diff --git a/build.rs b/build.rs
index 6cb26d0..950ac8e 100644
--- a/build.rs
+++ b/build.rs
@@ -12,7 +12,7 @@ fn main() {
 
     let _ = write!(out, "#[derive(Debug, Clone, AnyNode)]\n");
     let _ = write!(out, "pub enum AnyNode<'a> {{\n");
-    let _ = write!(out, "    Span(&'a Span<'a>),\n");
+    let _ = write!(out, "    Locate(&'a Locate),\n");
 
     let re_node = Regex::new(r"#\[derive.*Node.*\]").unwrap();
 
@@ -26,7 +26,7 @@ fn main() {
                 let line = line.unwrap();
                 if hit_node {
                     let name = line.split_whitespace().nth(2).unwrap().replace("<'a>", "");
-                    let _ = write!(out, "    {}(&'a {}<'a>),\n", name, name);
+                    let _ = write!(out, "    {}(&'a {}),\n", name, name);
                     hit_node = false;
                 }
                 if re_node.is_match(&line) {
diff --git a/src/ast/any_node.rs b/src/ast/any_node.rs
index 379b83a..bd54489 100644
--- a/src/ast/any_node.rs
+++ b/src/ast/any_node.rs
@@ -35,9 +35,9 @@ impl<'a> From<Vec<AnyNode<'a>>> for AnyNodes<'a> {
     }
 }
 
-impl<'a> From<&'a Span<'a>> for AnyNodes<'a> {
-    fn from(x: &'a Span<'a>) -> Self {
-        vec![AnyNode::Span(x)].into()
+impl<'a> From<&'a Locate> for AnyNodes<'a> {
+    fn from(x: &'a Locate) -> Self {
+        vec![AnyNode::Locate(x)].into()
     }
 }
 
@@ -327,11 +327,11 @@ where
     }
 }
 
-impl<'a, T> From<&'a Paren<'a, T>> for AnyNodes<'a>
+impl<'a, T> From<&'a Paren<T>> for AnyNodes<'a>
 where
     &'a T: Into<AnyNodes<'a>>,
 {
-    fn from(x: &'a Paren<'a, T>) -> Self {
+    fn from(x: &'a Paren<T>) -> Self {
         let mut ret = Vec::new();
         let (a, b, c) = &x.nodes;
         let mut a: AnyNodes<'a> = a.into();
@@ -343,11 +343,11 @@ where
     }
 }
 
-impl<'a, T> From<&'a Brace<'a, T>> for AnyNodes<'a>
+impl<'a, T> From<&'a Brace<T>> for AnyNodes<'a>
 where
     &'a T: Into<AnyNodes<'a>>,
 {
-    fn from(x: &'a Brace<'a, T>) -> Self {
+    fn from(x: &'a Brace<T>) -> Self {
         let mut ret = Vec::new();
         let (a, b, c) = &x.nodes;
         let mut a: AnyNodes<'a> = a.into();
@@ -359,11 +359,11 @@ where
     }
 }
 
-impl<'a, T> From<&'a Bracket<'a, T>> for AnyNodes<'a>
+impl<'a, T> From<&'a Bracket<T>> for AnyNodes<'a>
 where
     &'a T: Into<AnyNodes<'a>>,
 {
-    fn from(x: &'a Bracket<'a, T>) -> Self {
+    fn from(x: &'a Bracket<T>) -> Self {
         let mut ret = Vec::new();
         let (a, b, c) = &x.nodes;
         let mut a: AnyNodes<'a> = a.into();
@@ -375,11 +375,11 @@ where
     }
 }
 
-impl<'a, T> From<&'a ApostropheBrace<'a, T>> for AnyNodes<'a>
+impl<'a, T> From<&'a ApostropheBrace<T>> for AnyNodes<'a>
 where
     &'a T: Into<AnyNodes<'a>>,
 {
-    fn from(x: &'a ApostropheBrace<'a, T>) -> Self {
+    fn from(x: &'a ApostropheBrace<T>) -> Self {
         let mut ret = Vec::new();
         let (a, b, c) = &x.nodes;
         let mut a: AnyNodes<'a> = a.into();
diff --git a/src/ast/node.rs b/src/ast/node.rs
index 6793989..e49545d 100644
--- a/src/ast/node.rs
+++ b/src/ast/node.rs
@@ -5,7 +5,7 @@ pub trait Node<'a> {
     fn next(&'a self) -> AnyNodes<'a>;
 }
 
-impl<'a> Node<'a> for Span<'a> {
+impl<'a> Node<'a> for Locate {
     fn next(&'a self) -> AnyNodes<'a> {
         vec![].into()
     }
diff --git a/src/parser.rs b/src/parser.rs
index 753d4d3..539839a 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -32,6 +32,23 @@ pub struct Extra {
 
 pub type Span<'a> = nom_locate::LocatedSpanEx<&'a str, Extra>;
 
+#[derive(Copy, Clone, Default, Debug, PartialEq)]
+pub struct Locate {
+    offset: usize,
+    line: u32,
+    len: usize,
+}
+
+impl<'a> From<Span<'a>> for Locate {
+    fn from(x: Span<'a>) -> Self {
+        Locate {
+            offset: x.offset,
+            line: x.line,
+            len: x.fragment.len(),
+        }
+    }
+}
+
 mod thread_context {
 
     use crate::parser::RECURSIVE_FLAG_WORDS;
@@ -75,4 +92,10 @@ mod thread_context {
             RefCell::new(HashMap::new())
         }
     );
+
+    //thread_local!(
+    //    pub static MEMO: RefCell<HashMap<(&'static str, usize), AnyNode>> = {
+    //        RefCell::new(HashMap::new())
+    //    }
+    //);
 }
diff --git a/src/parser/behavioral_statements/assertion_statements.rs b/src/parser/behavioral_statements/assertion_statements.rs
index 1882c94..daf83b2 100644
--- a/src/parser/behavioral_statements/assertion_statements.rs
+++ b/src/parser/behavioral_statements/assertion_statements.rs
@@ -8,95 +8,80 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum AssertionItem<'a> {
-    Concurrent(ConcurrentAssertionItem<'a>),
-    Immediate(DeferredImmediateAssetionItem<'a>),
+pub enum AssertionItem {
+    Concurrent(ConcurrentAssertionItem),
+    Immediate(DeferredImmediateAssetionItem),
 }
 
 #[derive(Debug, Node)]
-pub struct DeferredImmediateAssetionItem<'a> {
+pub struct DeferredImmediateAssetionItem {
     pub nodes: (
-        Option<(BlockIdentifier<'a>, Symbol<'a>)>,
-        DeferredImmediateAssertionStatement<'a>,
+        Option<(BlockIdentifier, Symbol)>,
+        DeferredImmediateAssertionStatement,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ProceduralAssertionStatement<'a> {
-    Concurrent(ConcurrentAssertionStatement<'a>),
-    Immediate(ImmediateAssetionStatement<'a>),
-    Checker(CheckerInstantiation<'a>),
+pub enum ProceduralAssertionStatement {
+    Concurrent(ConcurrentAssertionStatement),
+    Immediate(ImmediateAssetionStatement),
+    Checker(CheckerInstantiation),
 }
 
 #[derive(Debug, Node)]
-pub enum ImmediateAssetionStatement<'a> {
-    Simple(SimpleImmediateAssertionStatement<'a>),
-    Deferred(DeferredImmediateAssertionStatement<'a>),
+pub enum ImmediateAssetionStatement {
+    Simple(SimpleImmediateAssertionStatement),
+    Deferred(DeferredImmediateAssertionStatement),
 }
 
 #[derive(Debug, Node)]
-pub enum SimpleImmediateAssertionStatement<'a> {
-    Assert(SimpleImmediateAssertStatement<'a>),
-    Assume(SimpleImmediateAssumeStatement<'a>),
-    Cover(SimpleImmediateCoverStatement<'a>),
+pub enum SimpleImmediateAssertionStatement {
+    Assert(SimpleImmediateAssertStatement),
+    Assume(SimpleImmediateAssumeStatement),
+    Cover(SimpleImmediateCoverStatement),
 }
 
 #[derive(Debug, Node)]
-pub struct SimpleImmediateAssertStatement<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, ActionBlock<'a>),
+pub struct SimpleImmediateAssertStatement {
+    pub nodes: (Keyword, Paren<Expression>, ActionBlock),
 }
 
 #[derive(Debug, Node)]
-pub struct SimpleImmediateAssumeStatement<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, ActionBlock<'a>),
+pub struct SimpleImmediateAssumeStatement {
+    pub nodes: (Keyword, Paren<Expression>, ActionBlock),
 }
 
 #[derive(Debug, Node)]
-pub struct SimpleImmediateCoverStatement<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, StatementOrNull<'a>),
+pub struct SimpleImmediateCoverStatement {
+    pub nodes: (Keyword, Paren<Expression>, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub enum DeferredImmediateAssertionStatement<'a> {
-    Assert(DeferredImmediateAssertStatement<'a>),
-    Assume(DeferredImmediateAssumeStatement<'a>),
-    Cover(DeferredImmediateCoverStatement<'a>),
+pub enum DeferredImmediateAssertionStatement {
+    Assert(DeferredImmediateAssertStatement),
+    Assume(DeferredImmediateAssumeStatement),
+    Cover(DeferredImmediateCoverStatement),
 }
 
 #[derive(Debug, Node)]
-pub struct DeferredImmediateAssertStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        AssertTiming<'a>,
-        Paren<'a, Expression<'a>>,
-        ActionBlock<'a>,
-    ),
+pub struct DeferredImmediateAssertStatement {
+    pub nodes: (Keyword, AssertTiming, Paren<Expression>, ActionBlock),
 }
 
 #[derive(Debug, Node)]
-pub struct DeferredImmediateAssumeStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        AssertTiming<'a>,
-        Paren<'a, Expression<'a>>,
-        ActionBlock<'a>,
-    ),
+pub struct DeferredImmediateAssumeStatement {
+    pub nodes: (Keyword, AssertTiming, Paren<Expression>, ActionBlock),
 }
 
 #[derive(Debug, Node)]
-pub struct DeferredImmediateCoverStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        AssertTiming<'a>,
-        Paren<'a, Expression<'a>>,
-        StatementOrNull<'a>,
-    ),
+pub struct DeferredImmediateCoverStatement {
+    pub nodes: (Keyword, AssertTiming, Paren<Expression>, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub enum AssertTiming<'a> {
-    Zero(Symbol<'a>),
-    Final(Keyword<'a>),
+pub enum AssertTiming {
+    Zero(Symbol),
+    Final(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/case_statements.rs b/src/parser/behavioral_statements/case_statements.rs
index b189e5e..190041d 100644
--- a/src/parser/behavioral_statements/case_statements.rs
+++ b/src/parser/behavioral_statements/case_statements.rs
@@ -9,137 +9,128 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum CaseStatement<'a> {
-    Normal(CaseStatementNormal<'a>),
-    Matches(CaseStatementMatches<'a>),
-    Inside(CaseStatementInside<'a>),
+pub enum CaseStatement {
+    Normal(CaseStatementNormal),
+    Matches(CaseStatementMatches),
+    Inside(CaseStatementInside),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseStatementNormal<'a> {
+pub struct CaseStatementNormal {
     pub nodes: (
-        Option<UniquePriority<'a>>,
-        CaseKeyword<'a>,
-        Paren<'a, CaseExpression<'a>>,
-        CaseItem<'a>,
-        Vec<CaseItem<'a>>,
-        Keyword<'a>,
+        Option<UniquePriority>,
+        CaseKeyword,
+        Paren<CaseExpression>,
+        CaseItem,
+        Vec<CaseItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseStatementMatches<'a> {
+pub struct CaseStatementMatches {
     pub nodes: (
-        Option<UniquePriority<'a>>,
-        CaseKeyword<'a>,
-        Paren<'a, CaseExpression<'a>>,
-        Keyword<'a>,
-        CasePatternItem<'a>,
-        Vec<CasePatternItem<'a>>,
-        Keyword<'a>,
+        Option<UniquePriority>,
+        CaseKeyword,
+        Paren<CaseExpression>,
+        Keyword,
+        CasePatternItem,
+        Vec<CasePatternItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseStatementInside<'a> {
+pub struct CaseStatementInside {
     pub nodes: (
-        Option<UniquePriority<'a>>,
-        Keyword<'a>,
-        Paren<'a, CaseExpression<'a>>,
-        Keyword<'a>,
-        CaseInsideItem<'a>,
-        Vec<CaseInsideItem<'a>>,
-        Keyword<'a>,
+        Option<UniquePriority>,
+        Keyword,
+        Paren<CaseExpression>,
+        Keyword,
+        CaseInsideItem,
+        Vec<CaseInsideItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CaseKeyword<'a> {
-    Case(Keyword<'a>),
-    Casez(Keyword<'a>),
-    Casex(Keyword<'a>),
+pub enum CaseKeyword {
+    Case(Keyword),
+    Casez(Keyword),
+    Casex(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseExpression<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct CaseExpression {
+    pub nodes: (Expression,),
 }
 
 #[derive(Debug, Node)]
-pub enum CaseItem<'a> {
-    NonDefault(CaseItemNondefault<'a>),
-    Default(CaseItemDefault<'a>),
+pub enum CaseItem {
+    NonDefault(CaseItemNondefault),
+    Default(CaseItemDefault),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseItemNondefault<'a> {
+pub struct CaseItemNondefault {
+    pub nodes: (List<Symbol, CaseItemExpression>, Symbol, StatementOrNull),
+}
+
+#[derive(Debug, Node)]
+pub struct CaseItemDefault {
+    pub nodes: (Keyword, Option<Symbol>, StatementOrNull),
+}
+
+#[derive(Debug, Node)]
+pub enum CasePatternItem {
+    NonDefault(CasePatternItemNondefault),
+    Default(CaseItemDefault),
+}
+
+#[derive(Debug, Node)]
+pub struct CasePatternItemNondefault {
     pub nodes: (
-        List<Symbol<'a>, CaseItemExpression<'a>>,
-        Symbol<'a>,
-        StatementOrNull<'a>,
+        Pattern,
+        Option<(Symbol, Expression)>,
+        Symbol,
+        StatementOrNull,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseItemDefault<'a> {
-    pub nodes: (Keyword<'a>, Option<Symbol<'a>>, StatementOrNull<'a>),
+pub enum CaseInsideItem {
+    NonDefault(CaseInsideItemNondefault),
+    Default(CaseItemDefault),
 }
 
 #[derive(Debug, Node)]
-pub enum CasePatternItem<'a> {
-    NonDefault(CasePatternItemNondefault<'a>),
-    Default(CaseItemDefault<'a>),
+pub struct CaseInsideItemNondefault {
+    pub nodes: (OpenRangeList, Symbol, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct CasePatternItemNondefault<'a> {
-    pub nodes: (
-        Pattern<'a>,
-        Option<(Symbol<'a>, Expression<'a>)>,
-        Symbol<'a>,
-        StatementOrNull<'a>,
-    ),
+pub struct CaseItemExpression {
+    pub nodes: (Expression,),
 }
 
 #[derive(Debug, Node)]
-pub enum CaseInsideItem<'a> {
-    NonDefault(CaseInsideItemNondefault<'a>),
-    Default(CaseItemDefault<'a>),
+pub struct RandcaseStatement {
+    pub nodes: (Keyword, RandcaseItem, Vec<RandcaseItem>, Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseInsideItemNondefault<'a> {
-    pub nodes: (OpenRangeList<'a>, Symbol<'a>, StatementOrNull<'a>),
+pub struct RandcaseItem {
+    pub nodes: (Expression, Symbol, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseItemExpression<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct OpenRangeList {
+    pub nodes: (List<Symbol, OpenValueRange>,),
 }
 
 #[derive(Debug, Node)]
-pub struct RandcaseStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        RandcaseItem<'a>,
-        Vec<RandcaseItem<'a>>,
-        Keyword<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct RandcaseItem<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, StatementOrNull<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct OpenRangeList<'a> {
-    pub nodes: (List<Symbol<'a>, OpenValueRange<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub struct OpenValueRange<'a> {
-    pub nodes: (ValueRange<'a>,),
+pub struct OpenValueRange {
+    pub nodes: (ValueRange,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/clocking_block.rs b/src/parser/behavioral_statements/clocking_block.rs
index d7d2e9c..7276bc4 100644
--- a/src/parser/behavioral_statements/clocking_block.rs
+++ b/src/parser/behavioral_statements/clocking_block.rs
@@ -9,196 +9,182 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ClockingDeclaration<'a> {
-    Local(ClockingDeclarationLocal<'a>),
-    Global(ClockingDeclarationGlobal<'a>),
+pub enum ClockingDeclaration {
+    Local(ClockingDeclarationLocal),
+    Global(ClockingDeclarationGlobal),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDeclarationLocal<'a> {
+pub struct ClockingDeclarationLocal {
     pub nodes: (
-        Option<Default<'a>>,
-        Keyword<'a>,
-        Option<ClockingIdentifier<'a>>,
-        ClockingEvent<'a>,
-        Symbol<'a>,
-        Vec<ClockingItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ClockingIdentifier<'a>)>,
+        Option<Default>,
+        Keyword,
+        Option<ClockingIdentifier>,
+        ClockingEvent,
+        Symbol,
+        Vec<ClockingItem>,
+        Keyword,
+        Option<(Symbol, ClockingIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Default<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Default {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDeclarationGlobal<'a> {
+pub struct ClockingDeclarationGlobal {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Option<ClockingIdentifier<'a>>,
-        ClockingEvent<'a>,
-        Symbol<'a>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ClockingIdentifier<'a>)>,
+        Keyword,
+        Keyword,
+        Option<ClockingIdentifier>,
+        ClockingEvent,
+        Symbol,
+        Keyword,
+        Option<(Symbol, ClockingIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ClockingEvent<'a> {
-    Identifier(ClockingEventIdentifier<'a>),
-    Expression(ClockingEventExpression<'a>),
+pub enum ClockingEvent {
+    Identifier(ClockingEventIdentifier),
+    Expression(ClockingEventExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingEventIdentifier<'a> {
-    pub nodes: (Symbol<'a>, Identifier<'a>),
+pub struct ClockingEventIdentifier {
+    pub nodes: (Symbol, Identifier),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingEventExpression<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, EventExpression<'a>>),
+pub struct ClockingEventExpression {
+    pub nodes: (Symbol, Paren<EventExpression>),
 }
 
 #[derive(Debug, Node)]
-pub enum ClockingItem<'a> {
-    Default(ClockingItemDefault<'a>),
-    Direction(ClockingItemDirection<'a>),
-    Assertion(ClockingItemAssertion<'a>),
+pub enum ClockingItem {
+    Default(ClockingItemDefault),
+    Direction(ClockingItemDirection),
+    Assertion(ClockingItemAssertion),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingItemDefault<'a> {
-    pub nodes: (Keyword<'a>, DefaultSkew<'a>, Symbol<'a>),
+pub struct ClockingItemDefault {
+    pub nodes: (Keyword, DefaultSkew, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingItemDirection<'a> {
-    pub nodes: (
-        ClockingDirection<'a>,
-        ListOfClockingDeclAssign<'a>,
-        Symbol<'a>,
-    ),
+pub struct ClockingItemDirection {
+    pub nodes: (ClockingDirection, ListOfClockingDeclAssign, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingItemAssertion<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, AssertionItemDeclaration<'a>),
+pub struct ClockingItemAssertion {
+    pub nodes: (Vec<AttributeInstance>, AssertionItemDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum DefaultSkew<'a> {
-    Input(DefaultSkewInput<'a>),
-    Output(DefaultSkewOutput<'a>),
-    InputOutput(DefaultSkewInputOutput<'a>),
+pub enum DefaultSkew {
+    Input(DefaultSkewInput),
+    Output(DefaultSkewOutput),
+    InputOutput(DefaultSkewInputOutput),
 }
 
 #[derive(Debug, Node)]
-pub struct DefaultSkewInput<'a> {
-    pub nodes: (Keyword<'a>, ClockingSkew<'a>),
+pub struct DefaultSkewInput {
+    pub nodes: (Keyword, ClockingSkew),
 }
 
 #[derive(Debug, Node)]
-pub struct DefaultSkewOutput<'a> {
-    pub nodes: (Keyword<'a>, ClockingSkew<'a>),
+pub struct DefaultSkewOutput {
+    pub nodes: (Keyword, ClockingSkew),
 }
 
 #[derive(Debug, Node)]
-pub struct DefaultSkewInputOutput<'a> {
-    pub nodes: (Keyword<'a>, ClockingSkew<'a>, Keyword<'a>, ClockingSkew<'a>),
+pub struct DefaultSkewInputOutput {
+    pub nodes: (Keyword, ClockingSkew, Keyword, ClockingSkew),
 }
 
 #[derive(Debug, Node)]
-pub enum ClockingDirection<'a> {
-    Input(ClockingDirectionInput<'a>),
-    Output(ClockingDirectionOutput<'a>),
-    InputOutput(ClockingDirectionInputOutput<'a>),
-    Inout(Keyword<'a>),
+pub enum ClockingDirection {
+    Input(ClockingDirectionInput),
+    Output(ClockingDirectionOutput),
+    InputOutput(ClockingDirectionInputOutput),
+    Inout(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDirectionInput<'a> {
-    pub nodes: (Keyword<'a>, Option<ClockingSkew<'a>>),
+pub struct ClockingDirectionInput {
+    pub nodes: (Keyword, Option<ClockingSkew>),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDirectionOutput<'a> {
-    pub nodes: (Keyword<'a>, Option<ClockingSkew<'a>>),
+pub struct ClockingDirectionOutput {
+    pub nodes: (Keyword, Option<ClockingSkew>),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDirectionInputOutput<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Option<ClockingSkew<'a>>,
-        Keyword<'a>,
-        Option<ClockingSkew<'a>>,
-    ),
+pub struct ClockingDirectionInputOutput {
+    pub nodes: (Keyword, Option<ClockingSkew>, Keyword, Option<ClockingSkew>),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfClockingDeclAssign<'a> {
-    pub nodes: (List<Symbol<'a>, ClockingDeclAssign<'a>>,),
+pub struct ListOfClockingDeclAssign {
+    pub nodes: (List<Symbol, ClockingDeclAssign>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDeclAssign<'a> {
-    pub nodes: (SignalIdentifier<'a>, Option<(Symbol<'a>, Expression<'a>)>),
+pub struct ClockingDeclAssign {
+    pub nodes: (SignalIdentifier, Option<(Symbol, Expression)>),
 }
 
 #[derive(Debug, Node)]
-pub enum ClockingSkew<'a> {
-    Edge(ClockingSkewEdge<'a>),
-    DelayControl(DelayControl<'a>),
+pub enum ClockingSkew {
+    Edge(ClockingSkewEdge),
+    DelayControl(DelayControl),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingSkewEdge<'a> {
-    pub nodes: (EdgeIdentifier<'a>, Option<DelayControl<'a>>),
+pub struct ClockingSkewEdge {
+    pub nodes: (EdgeIdentifier, Option<DelayControl>),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingDrive<'a> {
-    pub nodes: (
-        ClockvarExpression<'a>,
-        Symbol<'a>,
-        Option<CycleDelay<'a>>,
-        Expression<'a>,
-    ),
+pub struct ClockingDrive {
+    pub nodes: (ClockvarExpression, Symbol, Option<CycleDelay>, Expression),
 }
 
 #[derive(Debug, Node)]
-pub enum CycleDelay<'a> {
-    Integral(CycleDelayIntegral<'a>),
-    Identifier(CycleDelayIdentifier<'a>),
-    Expression(CycleDelayExpression<'a>),
+pub enum CycleDelay {
+    Integral(CycleDelayIntegral),
+    Identifier(CycleDelayIdentifier),
+    Expression(CycleDelayExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct CycleDelayIntegral<'a> {
-    pub nodes: (Symbol<'a>, IntegralNumber<'a>),
+pub struct CycleDelayIntegral {
+    pub nodes: (Symbol, IntegralNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct CycleDelayIdentifier<'a> {
-    pub nodes: (Symbol<'a>, Identifier<'a>),
+pub struct CycleDelayIdentifier {
+    pub nodes: (Symbol, Identifier),
 }
 
 #[derive(Debug, Node)]
-pub struct CycleDelayExpression<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, Expression<'a>>),
+pub struct CycleDelayExpression {
+    pub nodes: (Symbol, Paren<Expression>),
 }
 
 #[derive(Debug, Node)]
-pub struct Clockvar<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct Clockvar {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockvarExpression<'a> {
-    pub nodes: (Clockvar<'a>, Select<'a>),
+pub struct ClockvarExpression {
+    pub nodes: (Clockvar, Select),
 }
 // -----------------------------------------------------------------------------
 
diff --git a/src/parser/behavioral_statements/conditional_statements.rs b/src/parser/behavioral_statements/conditional_statements.rs
index 6264072..b527e63 100644
--- a/src/parser/behavioral_statements/conditional_statements.rs
+++ b/src/parser/behavioral_statements/conditional_statements.rs
@@ -9,43 +9,38 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ConditionalStatement<'a> {
+pub struct ConditionalStatement {
     pub nodes: (
-        Option<UniquePriority<'a>>,
-        Keyword<'a>,
-        Paren<'a, CondPredicate<'a>>,
-        StatementOrNull<'a>,
-        Vec<(
-            Keyword<'a>,
-            Keyword<'a>,
-            Paren<'a, CondPredicate<'a>>,
-            StatementOrNull<'a>,
-        )>,
-        Option<(Keyword<'a>, StatementOrNull<'a>)>,
+        Option<UniquePriority>,
+        Keyword,
+        Paren<CondPredicate>,
+        StatementOrNull,
+        Vec<(Keyword, Keyword, Paren<CondPredicate>, StatementOrNull)>,
+        Option<(Keyword, StatementOrNull)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum UniquePriority<'a> {
-    Unique(Keyword<'a>),
-    Unique0(Keyword<'a>),
-    Priority(Keyword<'a>),
+pub enum UniquePriority {
+    Unique(Keyword),
+    Unique0(Keyword),
+    Priority(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct CondPredicate<'a> {
-    pub nodes: (List<Symbol<'a>, ExpressionOrCondPattern<'a>>,),
+pub struct CondPredicate {
+    pub nodes: (List<Symbol, ExpressionOrCondPattern>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ExpressionOrCondPattern<'a> {
-    Expression(Expression<'a>),
-    CondPattern(CondPattern<'a>),
+pub enum ExpressionOrCondPattern {
+    Expression(Expression),
+    CondPattern(CondPattern),
 }
 
 #[derive(Debug, Node)]
-pub struct CondPattern<'a> {
-    pub nodes: (Expression<'a>, Keyword<'a>, Pattern<'a>),
+pub struct CondPattern {
+    pub nodes: (Expression, Keyword, Pattern),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/continuous_assignment_and_net_alias_statements.rs b/src/parser/behavioral_statements/continuous_assignment_and_net_alias_statements.rs
index ad4105c..8068d5d 100644
--- a/src/parser/behavioral_statements/continuous_assignment_and_net_alias_statements.rs
+++ b/src/parser/behavioral_statements/continuous_assignment_and_net_alias_statements.rs
@@ -7,56 +7,56 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ContinuousAssign<'a> {
-    Net(ContinuousAssignNet<'a>),
-    Variable(ContinuousAssignVariable<'a>),
+pub enum ContinuousAssign {
+    Net(ContinuousAssignNet),
+    Variable(ContinuousAssignVariable),
 }
 
 #[derive(Debug, Node)]
-pub struct ContinuousAssignNet<'a> {
+pub struct ContinuousAssignNet {
     pub nodes: (
-        Keyword<'a>,
-        Option<DriveStrength<'a>>,
-        Option<Delay3<'a>>,
-        ListOfNetAssignments<'a>,
-        Symbol<'a>,
+        Keyword,
+        Option<DriveStrength>,
+        Option<Delay3>,
+        ListOfNetAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ContinuousAssignVariable<'a> {
+pub struct ContinuousAssignVariable {
     pub nodes: (
-        Keyword<'a>,
-        Option<DelayControl<'a>>,
-        ListOfVariableAssignments<'a>,
-        Symbol<'a>,
+        Keyword,
+        Option<DelayControl>,
+        ListOfVariableAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfNetAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, NetAssignment<'a>>,),
+pub struct ListOfNetAssignments {
+    pub nodes: (List<Symbol, NetAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfVariableAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, VariableAssignment<'a>>,),
+pub struct ListOfVariableAssignments {
+    pub nodes: (List<Symbol, VariableAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct NetAlias<'a> {
+pub struct NetAlias {
     pub nodes: (
-        Keyword<'a>,
-        NetLvalue<'a>,
-        Symbol<'a>,
-        List<Symbol<'a>, NetLvalue<'a>>,
-        Symbol<'a>,
+        Keyword,
+        NetLvalue,
+        Symbol,
+        List<Symbol, NetLvalue>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NetAssignment<'a> {
-    pub nodes: (NetLvalue<'a>, Symbol<'a>, Expression<'a>),
+pub struct NetAssignment {
+    pub nodes: (NetLvalue, Symbol, Expression),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/looping_statements.rs b/src/parser/behavioral_statements/looping_statements.rs
index 3ce7493..70262f3 100644
--- a/src/parser/behavioral_statements/looping_statements.rs
+++ b/src/parser/behavioral_statements/looping_statements.rs
@@ -8,114 +8,99 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum LoopStatement<'a> {
-    Forever(LoopStatementForever<'a>),
-    Repeat(LoopStatementRepeat<'a>),
-    While(LoopStatementWhile<'a>),
-    For(LoopStatementFor<'a>),
-    DoWhile(LoopStatementDoWhile<'a>),
-    Foreach(LoopStatementForeach<'a>),
+pub enum LoopStatement {
+    Forever(LoopStatementForever),
+    Repeat(LoopStatementRepeat),
+    While(LoopStatementWhile),
+    For(LoopStatementFor),
+    DoWhile(LoopStatementDoWhile),
+    Foreach(LoopStatementForeach),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementForever<'a> {
-    pub nodes: (Keyword<'a>, StatementOrNull<'a>),
+pub struct LoopStatementForever {
+    pub nodes: (Keyword, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementRepeat<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, StatementOrNull<'a>),
+pub struct LoopStatementRepeat {
+    pub nodes: (Keyword, Paren<Expression>, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementWhile<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, StatementOrNull<'a>),
+pub struct LoopStatementWhile {
+    pub nodes: (Keyword, Paren<Expression>, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementFor<'a> {
+pub struct LoopStatementFor {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                Option<ForInitialization<'a>>,
-                Symbol<'a>,
-                Option<Expression<'a>>,
-                Symbol<'a>,
-                Option<ForStep<'a>>,
-            ),
-        >,
-        StatementOrNull<'a>,
+        Keyword,
+        Paren<(
+            Option<ForInitialization>,
+            Symbol,
+            Option<Expression>,
+            Symbol,
+            Option<ForStep>,
+        )>,
+        StatementOrNull,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementDoWhile<'a> {
+pub struct LoopStatementDoWhile {
+    pub nodes: (Keyword, StatementOrNull, Keyword, Paren<Expression>, Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct LoopStatementForeach {
     pub nodes: (
-        Keyword<'a>,
-        StatementOrNull<'a>,
-        Keyword<'a>,
-        Paren<'a, Expression<'a>>,
-        Symbol<'a>,
+        Keyword,
+        Paren<(PsOrHierarchicalArrayIdentifier, Bracket<LoopVariables>)>,
+        Statement,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopStatementForeach<'a> {
+pub enum ForInitialization {
+    ListOfVariableAssignments(ListOfVariableAssignments),
+    Declaration(ForInitializationDeclaration),
+}
+
+#[derive(Debug, Node)]
+pub struct ForInitializationDeclaration {
+    pub nodes: (List<Symbol, ForVariableDeclaration>,),
+}
+
+#[derive(Debug, Node)]
+pub struct ForVariableDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                PsOrHierarchicalArrayIdentifier<'a>,
-                Bracket<'a, LoopVariables<'a>>,
-            ),
-        >,
-        Statement<'a>,
+        Option<Var>,
+        DataType,
+        List<Symbol, (VariableIdentifier, Symbol, Expression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ForInitialization<'a> {
-    ListOfVariableAssignments(ListOfVariableAssignments<'a>),
-    Declaration(ForInitializationDeclaration<'a>),
+pub struct Var {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct ForInitializationDeclaration<'a> {
-    pub nodes: (List<Symbol<'a>, ForVariableDeclaration<'a>>,),
+pub struct ForStep {
+    pub nodes: (List<Symbol, ForStepAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ForVariableDeclaration<'a> {
-    pub nodes: (
-        Option<Var<'a>>,
-        DataType<'a>,
-        List<Symbol<'a>, (VariableIdentifier<'a>, Symbol<'a>, Expression<'a>)>,
-    ),
+pub enum ForStepAssignment {
+    OperatorAssignment(OperatorAssignment),
+    IncOrDecExpression(IncOrDecExpression),
+    FunctionSubroutineCall(FunctionSubroutineCall),
 }
 
 #[derive(Debug, Node)]
-pub struct Var<'a> {
-    pub nodes: (Keyword<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct ForStep<'a> {
-    pub nodes: (List<Symbol<'a>, ForStepAssignment<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub enum ForStepAssignment<'a> {
-    OperatorAssignment(OperatorAssignment<'a>),
-    IncOrDecExpression(IncOrDecExpression<'a>),
-    FunctionSubroutineCall(FunctionSubroutineCall<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct LoopVariables<'a> {
-    pub nodes: (List<Symbol<'a>, Option<IndexVariableIdentifier<'a>>>,),
+pub struct LoopVariables {
+    pub nodes: (List<Symbol, Option<IndexVariableIdentifier>>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/parallel_and_sequential_blocks.rs b/src/parser/behavioral_statements/parallel_and_sequential_blocks.rs
index 34adc0b..c92d24b 100644
--- a/src/parser/behavioral_statements/parallel_and_sequential_blocks.rs
+++ b/src/parser/behavioral_statements/parallel_and_sequential_blocks.rs
@@ -9,45 +9,45 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ActionBlock<'a> {
-    StatementOrNull(StatementOrNull<'a>),
-    Else(ActionBlockElse<'a>),
+pub enum ActionBlock {
+    StatementOrNull(StatementOrNull),
+    Else(ActionBlockElse),
 }
 
 #[derive(Debug, Node)]
-pub struct ActionBlockElse<'a> {
-    pub nodes: (Option<Statement<'a>>, Keyword<'a>, StatementOrNull<'a>),
+pub struct ActionBlockElse {
+    pub nodes: (Option<Statement>, Keyword, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct SeqBlock<'a> {
+pub struct SeqBlock {
     pub nodes: (
-        Keyword<'a>,
-        Option<(Symbol<'a>, BlockIdentifier<'a>)>,
-        Vec<BlockItemDeclaration<'a>>,
-        Vec<StatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, BlockIdentifier<'a>)>,
+        Keyword,
+        Option<(Symbol, BlockIdentifier)>,
+        Vec<BlockItemDeclaration>,
+        Vec<StatementOrNull>,
+        Keyword,
+        Option<(Symbol, BlockIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParBlock<'a> {
+pub struct ParBlock {
     pub nodes: (
-        Keyword<'a>,
-        Option<(Symbol<'a>, BlockIdentifier<'a>)>,
-        Vec<BlockItemDeclaration<'a>>,
-        Vec<StatementOrNull<'a>>,
-        JoinKeyword<'a>,
-        Option<(Symbol<'a>, BlockIdentifier<'a>)>,
+        Keyword,
+        Option<(Symbol, BlockIdentifier)>,
+        Vec<BlockItemDeclaration>,
+        Vec<StatementOrNull>,
+        JoinKeyword,
+        Option<(Symbol, BlockIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum JoinKeyword<'a> {
-    Join(Keyword<'a>),
-    JoinAny(Keyword<'a>),
-    JoinNone(Keyword<'a>),
+pub enum JoinKeyword {
+    Join(Keyword),
+    JoinAny(Keyword),
+    JoinNone(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/patterns.rs b/src/parser/behavioral_statements/patterns.rs
index b34d4ed..da813af 100644
--- a/src/parser/behavioral_statements/patterns.rs
+++ b/src/parser/behavioral_statements/patterns.rs
@@ -8,126 +8,107 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum Pattern<'a> {
-    Variable(Box<PatternVariable<'a>>),
-    Asterisk(Symbol<'a>),
-    ConstantExpression(Box<ConstantExpression<'a>>),
-    Tagged(Box<PatternTagged<'a>>),
-    List(Box<PatternList<'a>>),
-    IdentifierList(Box<PatternIdentifierList<'a>>),
+pub enum Pattern {
+    Variable(Box<PatternVariable>),
+    Asterisk(Symbol),
+    ConstantExpression(Box<ConstantExpression>),
+    Tagged(Box<PatternTagged>),
+    List(Box<PatternList>),
+    IdentifierList(Box<PatternIdentifierList>),
 }
 
 #[derive(Debug, Node)]
-pub struct PatternVariable<'a> {
-    pub nodes: (Symbol<'a>, VariableIdentifier<'a>),
+pub struct PatternVariable {
+    pub nodes: (Symbol, VariableIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PatternTagged<'a> {
-    pub nodes: (Keyword<'a>, MemberIdentifier<'a>, Option<Pattern<'a>>),
+pub struct PatternTagged {
+    pub nodes: (Keyword, MemberIdentifier, Option<Pattern>),
 }
 
 #[derive(Debug, Node)]
-pub struct PatternList<'a> {
-    pub nodes: (ApostropheBrace<'a, List<Symbol<'a>, Pattern<'a>>>,),
+pub struct PatternList {
+    pub nodes: (ApostropheBrace<List<Symbol, Pattern>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PatternIdentifierList<'a> {
-    pub nodes:
-        (ApostropheBrace<'a, List<Symbol<'a>, (MemberIdentifier<'a>, Symbol<'a>, Pattern<'a>)>>,),
+pub struct PatternIdentifierList {
+    pub nodes: (ApostropheBrace<List<Symbol, (MemberIdentifier, Symbol, Pattern)>>,),
 }
 
 #[derive(Debug, Node)]
-pub enum AssignmentPattern<'a> {
-    List(AssignmentPatternList<'a>),
-    Structure(AssignmentPatternStructure<'a>),
-    Array(AssignmentPatternArray<'a>),
-    Repeat(AssignmentPatternRepeat<'a>),
+pub enum AssignmentPattern {
+    List(AssignmentPatternList),
+    Structure(AssignmentPatternStructure),
+    Array(AssignmentPatternArray),
+    Repeat(AssignmentPatternRepeat),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternList<'a> {
-    pub nodes: (ApostropheBrace<'a, List<Symbol<'a>, Expression<'a>>>,),
+pub struct AssignmentPatternList {
+    pub nodes: (ApostropheBrace<List<Symbol, Expression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternStructure<'a> {
-    pub nodes: (
-        ApostropheBrace<
-            'a,
-            List<Symbol<'a>, (StructurePatternKey<'a>, Symbol<'a>, Expression<'a>)>,
-        >,
-    ),
+pub struct AssignmentPatternStructure {
+    pub nodes: (ApostropheBrace<List<Symbol, (StructurePatternKey, Symbol, Expression)>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternArray<'a> {
-    pub nodes: (
-        ApostropheBrace<'a, List<Symbol<'a>, (ArrayPatternKey<'a>, Symbol<'a>, Expression<'a>)>>,
-    ),
+pub struct AssignmentPatternArray {
+    pub nodes: (ApostropheBrace<List<Symbol, (ArrayPatternKey, Symbol, Expression)>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternRepeat<'a> {
-    pub nodes: (
-        ApostropheBrace<
-            'a,
-            (
-                ConstantExpression<'a>,
-                Brace<'a, List<Symbol<'a>, Expression<'a>>>,
-            ),
-        >,
-    ),
+pub struct AssignmentPatternRepeat {
+    pub nodes: (ApostropheBrace<(ConstantExpression, Brace<List<Symbol, Expression>>)>,),
 }
 
 #[derive(Debug, Node)]
-pub enum StructurePatternKey<'a> {
-    MemberIdentifier(MemberIdentifier<'a>),
-    AssignmentPatternKey(AssignmentPatternKey<'a>),
+pub enum StructurePatternKey {
+    MemberIdentifier(MemberIdentifier),
+    AssignmentPatternKey(AssignmentPatternKey),
 }
 
 #[derive(Debug, Node)]
-pub enum ArrayPatternKey<'a> {
-    ConstantExpression(ConstantExpression<'a>),
-    AssignmentPatternKey(AssignmentPatternKey<'a>),
+pub enum ArrayPatternKey {
+    ConstantExpression(ConstantExpression),
+    AssignmentPatternKey(AssignmentPatternKey),
 }
 
 #[derive(Debug, Node)]
-pub enum AssignmentPatternKey<'a> {
-    SimpleType(SimpleType<'a>),
-    Default(Keyword<'a>),
+pub enum AssignmentPatternKey {
+    SimpleType(SimpleType),
+    Default(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternExpression<'a> {
-    pub nodes: (
-        Option<AssignmentPatternExpressionType<'a>>,
-        AssignmentPattern<'a>,
-    ),
+pub struct AssignmentPatternExpression {
+    pub nodes: (Option<AssignmentPatternExpressionType>, AssignmentPattern),
 }
 
 #[derive(Debug, Node)]
-pub enum AssignmentPatternExpressionType<'a> {
-    PsTypeIdentifier(PsTypeIdentifier<'a>),
-    PsParameterIdentifier(PsParameterIdentifier<'a>),
-    IntegerAtomType(IntegerAtomType<'a>),
-    TypeReference(TypeReference<'a>),
+pub enum AssignmentPatternExpressionType {
+    PsTypeIdentifier(PsTypeIdentifier),
+    PsParameterIdentifier(PsParameterIdentifier),
+    IntegerAtomType(IntegerAtomType),
+    TypeReference(TypeReference),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantAssignmentPatternExpression<'a> {
-    pub nodes: (AssignmentPatternExpression<'a>,),
+pub struct ConstantAssignmentPatternExpression {
+    pub nodes: (AssignmentPatternExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternNetLvalue<'a> {
-    pub nodes: (ApostropheBrace<'a, List<Symbol<'a>, NetLvalue<'a>>>,),
+pub struct AssignmentPatternNetLvalue {
+    pub nodes: (ApostropheBrace<List<Symbol, NetLvalue>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentPatternVariableLvalue<'a> {
-    pub nodes: (ApostropheBrace<'a, List<Symbol<'a>, VariableLvalue<'a>>>,),
+pub struct AssignmentPatternVariableLvalue {
+    pub nodes: (ApostropheBrace<List<Symbol, VariableLvalue>>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/procedural_blocks_and_assignments.rs b/src/parser/behavioral_statements/procedural_blocks_and_assignments.rs
index 5ee9e99..0998443 100644
--- a/src/parser/behavioral_statements/procedural_blocks_and_assignments.rs
+++ b/src/parser/behavioral_statements/procedural_blocks_and_assignments.rs
@@ -7,125 +7,125 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct InitialConstruct<'a> {
-    pub nodes: (Keyword<'a>, StatementOrNull<'a>),
+pub struct InitialConstruct {
+    pub nodes: (Keyword, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct AlwaysConstruct<'a> {
-    pub nodes: (AlwaysKeyword<'a>, Statement<'a>),
+pub struct AlwaysConstruct {
+    pub nodes: (AlwaysKeyword, Statement),
 }
 
 #[derive(Debug, Node)]
-pub enum AlwaysKeyword<'a> {
-    Always(Keyword<'a>),
-    AlwaysComb(Keyword<'a>),
-    AlwaysLatch(Keyword<'a>),
-    AlwaysFf(Keyword<'a>),
+pub enum AlwaysKeyword {
+    Always(Keyword),
+    AlwaysComb(Keyword),
+    AlwaysLatch(Keyword),
+    AlwaysFf(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct FinalConstruct<'a> {
-    pub nodes: (Keyword<'a>, FunctionStatement<'a>),
+pub struct FinalConstruct {
+    pub nodes: (Keyword, FunctionStatement),
 }
 
 #[derive(Debug, Node)]
-pub enum BlockingAssignment<'a> {
-    Variable(BlockingAssignmentVariable<'a>),
-    NonrangeVariable(BlockingAssignmentNonrangeVariable<'a>),
-    HierarchicalVariable(BlockingAssignmentHierarchicalVariable<'a>),
-    OperatorAssignment(OperatorAssignment<'a>),
+pub enum BlockingAssignment {
+    Variable(BlockingAssignmentVariable),
+    NonrangeVariable(BlockingAssignmentNonrangeVariable),
+    HierarchicalVariable(BlockingAssignmentHierarchicalVariable),
+    OperatorAssignment(OperatorAssignment),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockingAssignmentVariable<'a> {
+pub struct BlockingAssignmentVariable {
     pub nodes: (
-        VariableLvalue<'a>,
-        Symbol<'a>,
-        DelayOrEventControl<'a>,
-        Expression<'a>,
+        VariableLvalue,
+        Symbol,
+        DelayOrEventControl,
+        Expression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockingAssignmentNonrangeVariable<'a> {
-    pub nodes: (NonrangeVariableLvalue<'a>, Symbol<'a>, DynamicArrayNew<'a>),
+pub struct BlockingAssignmentNonrangeVariable {
+    pub nodes: (NonrangeVariableLvalue, Symbol, DynamicArrayNew),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockingAssignmentHierarchicalVariable<'a> {
+pub struct BlockingAssignmentHierarchicalVariable {
     pub nodes: (
-        Option<ImplicitClassHandleOrClassScopeOrPackageScope<'a>>,
-        HierarchicalVariableIdentifier<'a>,
-        Select<'a>,
-        Symbol<'a>,
-        ClassNew<'a>,
+        Option<ImplicitClassHandleOrClassScopeOrPackageScope>,
+        HierarchicalVariableIdentifier,
+        Select,
+        Symbol,
+        ClassNew,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct OperatorAssignment<'a> {
-    pub nodes: (VariableLvalue<'a>, AssignmentOperator<'a>, Expression<'a>),
+pub struct OperatorAssignment {
+    pub nodes: (VariableLvalue, AssignmentOperator, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct AssignmentOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct AssignmentOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct NonblockingAssignment<'a> {
+pub struct NonblockingAssignment {
     pub nodes: (
-        VariableLvalue<'a>,
-        Symbol<'a>,
-        Option<DelayOrEventControl<'a>>,
-        Expression<'a>,
+        VariableLvalue,
+        Symbol,
+        Option<DelayOrEventControl>,
+        Expression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ProceduralContinuousAssignment<'a> {
-    Assign(ProceduralContinuousAssignmentAssign<'a>),
-    Deassign(ProceduralContinuousAssignmentDeassign<'a>),
-    ForceVariable(ProceduralContinuousAssignmentForceVariable<'a>),
-    ForceNet(ProceduralContinuousAssignmentForceNet<'a>),
-    ReleaseVariable(ProceduralContinuousAssignmentReleaseVariable<'a>),
-    ReleaseNet(ProceduralContinuousAssignmentReleaseNet<'a>),
+pub enum ProceduralContinuousAssignment {
+    Assign(ProceduralContinuousAssignmentAssign),
+    Deassign(ProceduralContinuousAssignmentDeassign),
+    ForceVariable(ProceduralContinuousAssignmentForceVariable),
+    ForceNet(ProceduralContinuousAssignmentForceNet),
+    ReleaseVariable(ProceduralContinuousAssignmentReleaseVariable),
+    ReleaseNet(ProceduralContinuousAssignmentReleaseNet),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentAssign<'a> {
-    pub nodes: (Keyword<'a>, VariableAssignment<'a>),
+pub struct ProceduralContinuousAssignmentAssign {
+    pub nodes: (Keyword, VariableAssignment),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentDeassign<'a> {
-    pub nodes: (Keyword<'a>, VariableLvalue<'a>),
+pub struct ProceduralContinuousAssignmentDeassign {
+    pub nodes: (Keyword, VariableLvalue),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentForceVariable<'a> {
-    pub nodes: (Keyword<'a>, VariableAssignment<'a>),
+pub struct ProceduralContinuousAssignmentForceVariable {
+    pub nodes: (Keyword, VariableAssignment),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentForceNet<'a> {
-    pub nodes: (Keyword<'a>, NetAssignment<'a>),
+pub struct ProceduralContinuousAssignmentForceNet {
+    pub nodes: (Keyword, NetAssignment),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentReleaseVariable<'a> {
-    pub nodes: (Keyword<'a>, VariableLvalue<'a>),
+pub struct ProceduralContinuousAssignmentReleaseVariable {
+    pub nodes: (Keyword, VariableLvalue),
 }
 
 #[derive(Debug, Node)]
-pub struct ProceduralContinuousAssignmentReleaseNet<'a> {
-    pub nodes: (Keyword<'a>, NetLvalue<'a>),
+pub struct ProceduralContinuousAssignmentReleaseNet {
+    pub nodes: (Keyword, NetLvalue),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableAssignment<'a> {
-    pub nodes: (VariableLvalue<'a>, Symbol<'a>, Expression<'a>),
+pub struct VariableAssignment {
+    pub nodes: (VariableLvalue, Symbol, Expression),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/randsequence.rs b/src/parser/behavioral_statements/randsequence.rs
index 0fad411..0521141 100644
--- a/src/parser/behavioral_statements/randsequence.rs
+++ b/src/parser/behavioral_statements/randsequence.rs
@@ -9,143 +9,135 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct RandsequenceStatement<'a> {
+pub struct RandsequenceStatement {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, Option<ProductionIdentifier<'a>>>,
-        Production<'a>,
-        Vec<Production<'a>>,
-        Keyword<'a>,
+        Keyword,
+        Paren<Option<ProductionIdentifier>>,
+        Production,
+        Vec<Production>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Production<'a> {
+pub struct Production {
     pub nodes: (
-        Option<DataTypeOrVoid<'a>>,
-        ProductionIdentifier<'a>,
-        Option<Paren<'a, TfPortList<'a>>>,
-        Symbol<'a>,
-        List<Symbol<'a>, RsRule<'a>>,
-        Symbol<'a>,
+        Option<DataTypeOrVoid>,
+        ProductionIdentifier,
+        Option<Paren<TfPortList>>,
+        Symbol,
+        List<Symbol, RsRule>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RsRule<'a> {
+pub struct RsRule {
     pub nodes: (
-        RsProductionList<'a>,
-        Option<(Symbol<'a>, WeightSpecification<'a>, Option<RsCodeBlock<'a>>)>,
+        RsProductionList,
+        Option<(Symbol, WeightSpecification, Option<RsCodeBlock>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum RsProductionList<'a> {
-    Prod(RsProductionListProd<'a>),
-    Join(RsProductionListJoin<'a>),
+pub enum RsProductionList {
+    Prod(RsProductionListProd),
+    Join(RsProductionListJoin),
 }
 
 #[derive(Debug, Node)]
-pub struct RsProductionListProd<'a> {
-    pub nodes: (RsProd<'a>, Vec<RsProd<'a>>),
+pub struct RsProductionListProd {
+    pub nodes: (RsProd, Vec<RsProd>),
 }
 
 #[derive(Debug, Node)]
-pub struct RsProductionListJoin<'a> {
+pub struct RsProductionListJoin {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Option<Paren<'a, Expression<'a>>>,
-        ProductionItem<'a>,
-        ProductionItem<'a>,
-        Vec<ProductionItem<'a>>,
+        Keyword,
+        Keyword,
+        Option<Paren<Expression>>,
+        ProductionItem,
+        ProductionItem,
+        Vec<ProductionItem>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum WeightSpecification<'a> {
-    IntegralNumber(IntegralNumber<'a>),
-    PsIdentifier(PsIdentifier<'a>),
-    Expression(WeightSpecificationExpression<'a>),
+pub enum WeightSpecification {
+    IntegralNumber(IntegralNumber),
+    PsIdentifier(PsIdentifier),
+    Expression(WeightSpecificationExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct WeightSpecificationExpression<'a> {
-    pub nodes: (Paren<'a, Expression<'a>>,),
+pub struct WeightSpecificationExpression {
+    pub nodes: (Paren<Expression>,),
 }
 
 #[derive(Debug, Node)]
-pub struct RsCodeBlock<'a> {
-    pub nodes: (Brace<'a, (Vec<DataDeclaration<'a>>, Vec<StatementOrNull<'a>>)>,),
+pub struct RsCodeBlock {
+    pub nodes: (Brace<(Vec<DataDeclaration>, Vec<StatementOrNull>)>,),
 }
 
 #[derive(Debug, Node)]
-pub enum RsProd<'a> {
-    ProductionItem(ProductionItem<'a>),
-    RsCodeBlock(RsCodeBlock<'a>),
-    RsIfElse(RsIfElse<'a>),
-    RsRepeat(RsRepeat<'a>),
-    RsCase(RsCase<'a>),
+pub enum RsProd {
+    ProductionItem(ProductionItem),
+    RsCodeBlock(RsCodeBlock),
+    RsIfElse(RsIfElse),
+    RsRepeat(RsRepeat),
+    RsCase(RsCase),
 }
 
 #[derive(Debug, Node)]
-pub struct ProductionItem<'a> {
+pub struct ProductionItem {
+    pub nodes: (ProductionIdentifier, Option<Paren<ListOfArguments>>),
+}
+
+#[derive(Debug, Node)]
+pub struct RsIfElse {
     pub nodes: (
-        ProductionIdentifier<'a>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
+        Keyword,
+        Paren<Expression>,
+        ProductionItem,
+        Option<(Keyword, ProductionItem)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RsIfElse<'a> {
+pub struct RsRepeat {
+    pub nodes: (Keyword, Paren<Expression>, ProductionItem),
+}
+
+#[derive(Debug, Node)]
+pub struct RsCase {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, Expression<'a>>,
-        ProductionItem<'a>,
-        Option<(Keyword<'a>, ProductionItem<'a>)>,
+        Keyword,
+        Paren<CaseExpression>,
+        RsCaseItem,
+        Vec<RsCaseItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RsRepeat<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, ProductionItem<'a>),
+pub enum RsCaseItem {
+    NonDefault(RsCaseItemNondefault),
+    Default(RsCaseItemDefault),
 }
 
 #[derive(Debug, Node)]
-pub struct RsCase<'a> {
+pub struct RsCaseItemNondefault {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, CaseExpression<'a>>,
-        RsCaseItem<'a>,
-        Vec<RsCaseItem<'a>>,
-        Keyword<'a>,
+        List<Symbol, CaseItemExpression>,
+        Symbol,
+        ProductionItem,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum RsCaseItem<'a> {
-    NonDefault(RsCaseItemNondefault<'a>),
-    Default(RsCaseItemDefault<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct RsCaseItemNondefault<'a> {
-    pub nodes: (
-        List<Symbol<'a>, CaseItemExpression<'a>>,
-        Symbol<'a>,
-        ProductionItem<'a>,
-        Symbol<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct RsCaseItemDefault<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Option<Symbol<'a>>,
-        ProductionItem<'a>,
-        Symbol<'a>,
-    ),
+pub struct RsCaseItemDefault {
+    pub nodes: (Keyword, Option<Symbol>, ProductionItem, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/statements.rs b/src/parser/behavioral_statements/statements.rs
index 4da95e4..7568a01 100644
--- a/src/parser/behavioral_statements/statements.rs
+++ b/src/parser/behavioral_statements/statements.rs
@@ -9,68 +9,68 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum StatementOrNull<'a> {
-    Statement(Statement<'a>),
-    Attribute(StatementOrNullAttribute<'a>),
+pub enum StatementOrNull {
+    Statement(Statement),
+    Attribute(StatementOrNullAttribute),
 }
 
 #[derive(Debug, Node)]
-pub struct StatementOrNullAttribute<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Symbol<'a>),
+pub struct StatementOrNullAttribute {
+    pub nodes: (Vec<AttributeInstance>, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct Statement<'a> {
+pub struct Statement {
     pub nodes: (
-        Option<(BlockIdentifier<'a>, Symbol<'a>)>,
-        Vec<AttributeInstance<'a>>,
-        StatementItem<'a>,
+        Option<(BlockIdentifier, Symbol)>,
+        Vec<AttributeInstance>,
+        StatementItem,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum StatementItem<'a> {
-    BlockingAssignment(Box<(BlockingAssignment<'a>, Symbol<'a>)>),
-    NonblockingAssignment(Box<(NonblockingAssignment<'a>, Symbol<'a>)>),
-    ProceduralContinuousAssignment(Box<(ProceduralContinuousAssignment<'a>, Symbol<'a>)>),
-    CaseStatement(Box<CaseStatement<'a>>),
-    ConditionalStatement(Box<ConditionalStatement<'a>>),
-    IncOrDecExpression(Box<(IncOrDecExpression<'a>, Symbol<'a>)>),
-    SubroutineCallStatement(Box<SubroutineCallStatement<'a>>),
-    DisableStatement(Box<DisableStatement<'a>>),
-    EventTrigger(Box<EventTrigger<'a>>),
-    LoopStatement(Box<LoopStatement<'a>>),
-    JumpStatement(Box<JumpStatement<'a>>),
-    ParBlock(Box<ParBlock<'a>>),
-    ProceduralTimingControlStatement(Box<ProceduralTimingControlStatement<'a>>),
-    SeqBlock(Box<SeqBlock<'a>>),
-    WaitStatement(Box<WaitStatement<'a>>),
-    ProceduralAssertionStatement(Box<ProceduralAssertionStatement<'a>>),
-    ClockingDrive(Box<(ClockingDrive<'a>, Symbol<'a>)>),
-    RandsequenceStatement(Box<RandsequenceStatement<'a>>),
-    RandcaseStatement(Box<RandcaseStatement<'a>>),
-    ExpectPropertyStatement(Box<ExpectPropertyStatement<'a>>),
+pub enum StatementItem {
+    BlockingAssignment(Box<(BlockingAssignment, Symbol)>),
+    NonblockingAssignment(Box<(NonblockingAssignment, Symbol)>),
+    ProceduralContinuousAssignment(Box<(ProceduralContinuousAssignment, Symbol)>),
+    CaseStatement(Box<CaseStatement>),
+    ConditionalStatement(Box<ConditionalStatement>),
+    IncOrDecExpression(Box<(IncOrDecExpression, Symbol)>),
+    SubroutineCallStatement(Box<SubroutineCallStatement>),
+    DisableStatement(Box<DisableStatement>),
+    EventTrigger(Box<EventTrigger>),
+    LoopStatement(Box<LoopStatement>),
+    JumpStatement(Box<JumpStatement>),
+    ParBlock(Box<ParBlock>),
+    ProceduralTimingControlStatement(Box<ProceduralTimingControlStatement>),
+    SeqBlock(Box<SeqBlock>),
+    WaitStatement(Box<WaitStatement>),
+    ProceduralAssertionStatement(Box<ProceduralAssertionStatement>),
+    ClockingDrive(Box<(ClockingDrive, Symbol)>),
+    RandsequenceStatement(Box<RandsequenceStatement>),
+    RandcaseStatement(Box<RandcaseStatement>),
+    ExpectPropertyStatement(Box<ExpectPropertyStatement>),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionStatement<'a> {
-    pub nodes: (Statement<'a>,),
+pub struct FunctionStatement {
+    pub nodes: (Statement,),
 }
 
 #[derive(Debug, Node)]
-pub enum FunctionStatementOrNull<'a> {
-    Statement(FunctionStatement<'a>),
-    Attribute(FunctionStatementOrNullAttribute<'a>),
+pub enum FunctionStatementOrNull {
+    Statement(FunctionStatement),
+    Attribute(FunctionStatementOrNullAttribute),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionStatementOrNullAttribute<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Symbol<'a>),
+pub struct FunctionStatementOrNullAttribute {
+    pub nodes: (Vec<AttributeInstance>, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableIdentifierList<'a> {
-    pub nodes: (List<Symbol<'a>, VariableIdentifier<'a>>,),
+pub struct VariableIdentifierList {
+    pub nodes: (List<Symbol, VariableIdentifier>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/subroutine_call_statements.rs b/src/parser/behavioral_statements/subroutine_call_statements.rs
index fa2dc46..a06de3f 100644
--- a/src/parser/behavioral_statements/subroutine_call_statements.rs
+++ b/src/parser/behavioral_statements/subroutine_call_statements.rs
@@ -8,19 +8,14 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum SubroutineCallStatement<'a> {
-    SubroutineCall((SubroutineCall<'a>, Symbol<'a>)),
-    Function(SubroutineCallStatementFunction<'a>),
+pub enum SubroutineCallStatement {
+    SubroutineCall((SubroutineCall, Symbol)),
+    Function(SubroutineCallStatementFunction),
 }
 
 #[derive(Debug, Node)]
-pub struct SubroutineCallStatementFunction<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Symbol<'a>,
-        Paren<'a, FunctionSubroutineCall<'a>>,
-        Symbol<'a>,
-    ),
+pub struct SubroutineCallStatementFunction {
+    pub nodes: (Keyword, Symbol, Paren<FunctionSubroutineCall>, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/behavioral_statements/timing_control_statements.rs b/src/parser/behavioral_statements/timing_control_statements.rs
index ccc08d3..bd28582 100644
--- a/src/parser/behavioral_statements/timing_control_statements.rs
+++ b/src/parser/behavioral_statements/timing_control_statements.rs
@@ -8,206 +8,206 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ProceduralTimingControlStatement<'a> {
-    pub nodes: (ProceduralTimingControl<'a>, StatementOrNull<'a>),
+pub struct ProceduralTimingControlStatement {
+    pub nodes: (ProceduralTimingControl, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub enum DelayOrEventControl<'a> {
-    Delay(DelayControl<'a>),
-    Event(EventControl<'a>),
-    Repeat(DelayOrEventControlRepeat<'a>),
+pub enum DelayOrEventControl {
+    Delay(DelayControl),
+    Event(EventControl),
+    Repeat(DelayOrEventControlRepeat),
 }
 
 #[derive(Debug, Node)]
-pub struct DelayOrEventControlRepeat<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, EventControl<'a>),
+pub struct DelayOrEventControlRepeat {
+    pub nodes: (Keyword, Paren<Expression>, EventControl),
 }
 
 #[derive(Debug, Node)]
-pub enum DelayControl<'a> {
-    Delay(DelayControlDelay<'a>),
-    Mintypmax(DelayControlMintypmax<'a>),
+pub enum DelayControl {
+    Delay(DelayControlDelay),
+    Mintypmax(DelayControlMintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct DelayControlDelay<'a> {
-    pub nodes: (Symbol<'a>, DelayValue<'a>),
+pub struct DelayControlDelay {
+    pub nodes: (Symbol, DelayValue),
 }
 
 #[derive(Debug, Node)]
-pub struct DelayControlMintypmax<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, MintypmaxExpression<'a>>),
+pub struct DelayControlMintypmax {
+    pub nodes: (Symbol, Paren<MintypmaxExpression>),
 }
 
 #[derive(Debug, Node)]
-pub enum EventControl<'a> {
-    EventIdentifier(EventControlEventIdentifier<'a>),
-    EventExpression(EventControlEventExpression<'a>),
-    Asterisk(EventControlAsterisk<'a>),
-    ParenAsterisk(EventControlParenAsterisk<'a>),
-    SequenceIdentifier(EventControlSequenceIdentifier<'a>),
+pub enum EventControl {
+    EventIdentifier(EventControlEventIdentifier),
+    EventExpression(EventControlEventExpression),
+    Asterisk(EventControlAsterisk),
+    ParenAsterisk(EventControlParenAsterisk),
+    SequenceIdentifier(EventControlSequenceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct EventControlEventIdentifier<'a> {
-    pub nodes: (Symbol<'a>, HierarchicalEventIdentifier<'a>),
+pub struct EventControlEventIdentifier {
+    pub nodes: (Symbol, HierarchicalEventIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct EventControlEventExpression<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, EventExpression<'a>>),
+pub struct EventControlEventExpression {
+    pub nodes: (Symbol, Paren<EventExpression>),
 }
 
 #[derive(Debug, Node)]
-pub struct EventControlAsterisk<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct EventControlAsterisk {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct EventControlParenAsterisk<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, Symbol<'a>>),
+pub struct EventControlParenAsterisk {
+    pub nodes: (Symbol, Paren<Symbol>),
 }
 
 #[derive(Debug, Node)]
-pub struct EventControlSequenceIdentifier<'a> {
-    pub nodes: (Symbol<'a>, PsOrHierarchicalSequenceIdentifier<'a>),
+pub struct EventControlSequenceIdentifier {
+    pub nodes: (Symbol, PsOrHierarchicalSequenceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum EventExpression<'a> {
-    Expression(Box<EventExpressionExpression<'a>>),
-    Sequence(Box<EventExpressionSequence<'a>>),
-    Or(Box<EventExpressionOr<'a>>),
-    Comma(Box<EventExpressionComma<'a>>),
-    Paren(Box<EventExpressionParen<'a>>),
+pub enum EventExpression {
+    Expression(Box<EventExpressionExpression>),
+    Sequence(Box<EventExpressionSequence>),
+    Or(Box<EventExpressionOr>),
+    Comma(Box<EventExpressionComma>),
+    Paren(Box<EventExpressionParen>),
 }
 
 #[derive(Debug, Node)]
-pub struct EventExpressionExpression<'a> {
+pub struct EventExpressionExpression {
     pub nodes: (
-        Option<EdgeIdentifier<'a>>,
-        Expression<'a>,
-        Option<(Keyword<'a>, Expression<'a>)>,
+        Option<EdgeIdentifier>,
+        Expression,
+        Option<(Keyword, Expression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct EventExpressionSequence<'a> {
-    pub nodes: (SequenceInstance<'a>, Option<(Keyword<'a>, Expression<'a>)>),
+pub struct EventExpressionSequence {
+    pub nodes: (SequenceInstance, Option<(Keyword, Expression)>),
 }
 
 #[derive(Debug, Node)]
-pub struct EventExpressionOr<'a> {
-    pub nodes: (EventExpression<'a>, Keyword<'a>, EventExpression<'a>),
+pub struct EventExpressionOr {
+    pub nodes: (EventExpression, Keyword, EventExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct EventExpressionComma<'a> {
-    pub nodes: (EventExpression<'a>, Symbol<'a>, EventExpression<'a>),
+pub struct EventExpressionComma {
+    pub nodes: (EventExpression, Symbol, EventExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct EventExpressionParen<'a> {
-    pub nodes: (Paren<'a, EventExpression<'a>>,),
+pub struct EventExpressionParen {
+    pub nodes: (Paren<EventExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ProceduralTimingControl<'a> {
-    DelayControl(DelayControl<'a>),
-    EventControl(EventControl<'a>),
-    CycleDelay(CycleDelay<'a>),
+pub enum ProceduralTimingControl {
+    DelayControl(DelayControl),
+    EventControl(EventControl),
+    CycleDelay(CycleDelay),
 }
 
 #[derive(Debug, Node)]
-pub enum JumpStatement<'a> {
-    Return(JumpStatementReturn<'a>),
-    Break(JumpStatementBreak<'a>),
-    Continue(JumpStatementContinue<'a>),
+pub enum JumpStatement {
+    Return(JumpStatementReturn),
+    Break(JumpStatementBreak),
+    Continue(JumpStatementContinue),
 }
 
 #[derive(Debug, Node)]
-pub struct JumpStatementReturn<'a> {
-    pub nodes: (Keyword<'a>, Option<Expression<'a>>, Symbol<'a>),
+pub struct JumpStatementReturn {
+    pub nodes: (Keyword, Option<Expression>, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct JumpStatementBreak<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>),
+pub struct JumpStatementBreak {
+    pub nodes: (Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct JumpStatementContinue<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>),
+pub struct JumpStatementContinue {
+    pub nodes: (Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum WaitStatement<'a> {
-    Wait(WaitStatementWait<'a>),
-    Fork(WaitStatementFork<'a>),
-    Order(WaitStatementOrder<'a>),
+pub enum WaitStatement {
+    Wait(WaitStatementWait),
+    Fork(WaitStatementFork),
+    Order(WaitStatementOrder),
 }
 
 #[derive(Debug, Node)]
-pub struct WaitStatementWait<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>, StatementOrNull<'a>),
+pub struct WaitStatementWait {
+    pub nodes: (Keyword, Paren<Expression>, StatementOrNull),
 }
 
 #[derive(Debug, Node)]
-pub struct WaitStatementFork<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, Symbol<'a>),
+pub struct WaitStatementFork {
+    pub nodes: (Keyword, Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct WaitStatementOrder<'a> {
+pub struct WaitStatementOrder {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, List<Symbol<'a>, HierarchicalIdentifier<'a>>>,
-        ActionBlock<'a>,
+        Keyword,
+        Paren<List<Symbol, HierarchicalIdentifier>>,
+        ActionBlock,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum EventTrigger<'a> {
-    Named(EventTriggerNamed<'a>),
-    Nonblocking(EventTriggerNonblocking<'a>),
+pub enum EventTrigger {
+    Named(EventTriggerNamed),
+    Nonblocking(EventTriggerNonblocking),
 }
 
 #[derive(Debug, Node)]
-pub struct EventTriggerNamed<'a> {
-    pub nodes: (Symbol<'a>, HierarchicalEventIdentifier<'a>, Symbol<'a>),
+pub struct EventTriggerNamed {
+    pub nodes: (Symbol, HierarchicalEventIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct EventTriggerNonblocking<'a> {
+pub struct EventTriggerNonblocking {
     pub nodes: (
-        Symbol<'a>,
-        Option<DelayOrEventControl<'a>>,
-        HierarchicalEventIdentifier<'a>,
-        Symbol<'a>,
+        Symbol,
+        Option<DelayOrEventControl>,
+        HierarchicalEventIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum DisableStatement<'a> {
-    Task(DisableStatementTask<'a>),
-    Block(DisableStatementBlock<'a>),
-    Fork(DisableStatementFork<'a>),
+pub enum DisableStatement {
+    Task(DisableStatementTask),
+    Block(DisableStatementBlock),
+    Fork(DisableStatementFork),
 }
 
 #[derive(Debug, Node)]
-pub struct DisableStatementTask<'a> {
-    pub nodes: (Keyword<'a>, HierarchicalTaskIdentifier<'a>, Symbol<'a>),
+pub struct DisableStatementTask {
+    pub nodes: (Keyword, HierarchicalTaskIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct DisableStatementBlock<'a> {
-    pub nodes: (Keyword<'a>, HierarchicalBlockIdentifier<'a>, Symbol<'a>),
+pub struct DisableStatementBlock {
+    pub nodes: (Keyword, HierarchicalBlockIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct DisableStatementFork<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, Symbol<'a>),
+pub struct DisableStatementFork {
+    pub nodes: (Keyword, Keyword, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/assertion_declarations.rs b/src/parser/declarations/assertion_declarations.rs
index 5460966..6361dee 100644
--- a/src/parser/declarations/assertion_declarations.rs
+++ b/src/parser/declarations/assertion_declarations.rs
@@ -9,758 +9,662 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ConcurrentAssertionItem<'a> {
-    Statement(ConcurrentAssertionItemStatement<'a>),
-    CheckerInstantiation(CheckerInstantiation<'a>),
+pub enum ConcurrentAssertionItem {
+    Statement(ConcurrentAssertionItemStatement),
+    CheckerInstantiation(CheckerInstantiation),
 }
 
 #[derive(Debug, Node)]
-pub struct ConcurrentAssertionItemStatement<'a> {
+pub struct ConcurrentAssertionItemStatement {
     pub nodes: (
-        Option<(BlockIdentifier<'a>, Symbol<'a>)>,
-        ConcurrentAssertionStatement<'a>,
+        Option<(BlockIdentifier, Symbol)>,
+        ConcurrentAssertionStatement,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConcurrentAssertionStatement<'a> {
-    AssertPropertyStatement(AssertPropertyStatement<'a>),
-    AssumePropertyStatement(AssumePropertyStatement<'a>),
-    CoverPropertyStatement(CoverPropertyStatement<'a>),
-    CoverSequenceStatement(CoverSequenceStatement<'a>),
-    RestrictPropertyStatement(RestrictPropertyStatement<'a>),
+pub enum ConcurrentAssertionStatement {
+    AssertPropertyStatement(AssertPropertyStatement),
+    AssumePropertyStatement(AssumePropertyStatement),
+    CoverPropertyStatement(CoverPropertyStatement),
+    CoverSequenceStatement(CoverSequenceStatement),
+    RestrictPropertyStatement(RestrictPropertyStatement),
 }
 
 #[derive(Debug, Node)]
-pub struct AssertPropertyStatement<'a> {
+pub struct AssertPropertyStatement {
+    pub nodes: (Keyword, Keyword, Paren<PropertySpec>, ActionBlock),
+}
+
+#[derive(Debug, Node)]
+pub struct AssumePropertyStatement {
+    pub nodes: (Keyword, Keyword, Paren<PropertySpec>, ActionBlock),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverPropertyStatement {
+    pub nodes: (Keyword, Keyword, Paren<PropertySpec>, StatementOrNull),
+}
+
+#[derive(Debug, Node)]
+pub struct ExpectPropertyStatement {
+    pub nodes: (Keyword, Paren<PropertySpec>, ActionBlock),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverSequenceStatement {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<'a, PropertySpec<'a>>,
-        ActionBlock<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct AssumePropertyStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<'a, PropertySpec<'a>>,
-        ActionBlock<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct CoverPropertyStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<'a, PropertySpec<'a>>,
-        StatementOrNull<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct ExpectPropertyStatement<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, PropertySpec<'a>>, ActionBlock<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CoverSequenceStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                Option<ClockingEvent<'a>>,
-                Option<(Keyword<'a>, Keyword<'a>, Paren<'a, ExpressionOrDist<'a>>)>,
-                SequenceExpr<'a>,
-            ),
-        >,
-        StatementOrNull<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct RestrictPropertyStatement<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<'a, PropertySpec<'a>>,
-        Symbol<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyInstance<'a> {
-    pub nodes: (
-        PsOrHierarchicalPropertyIdentifier<'a>,
-        Option<Paren<'a, Option<PropertyListOfArguments<'a>>>>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum PropertyListOfArguments<'a> {
-    Ordered(PropertyListOfArgumentsOrdered<'a>),
-    Named(PropertyListOfArgumentsNamed<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyListOfArgumentsOrdered<'a> {
-    pub nodes: (
-        List<Symbol<'a>, Option<PropertyActualArg<'a>>>,
-        Vec<(
-            Symbol<'a>,
-            Symbol<'a>,
-            Identifier<'a>,
-            Paren<'a, Option<PropertyActualArg<'a>>>,
+        Keyword,
+        Keyword,
+        Paren<(
+            Option<ClockingEvent>,
+            Option<(Keyword, Keyword, Paren<ExpressionOrDist>)>,
+            SequenceExpr,
         )>,
+        StatementOrNull,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyListOfArgumentsNamed<'a> {
+pub struct RestrictPropertyStatement {
+    pub nodes: (Keyword, Keyword, Paren<PropertySpec>, Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyInstance {
     pub nodes: (
-        List<
-            Symbol<'a>,
-            (
-                Symbol<'a>,
-                Identifier<'a>,
-                Paren<'a, Option<PropertyActualArg<'a>>>,
-            ),
-        >,
+        PsOrHierarchicalPropertyIdentifier,
+        Option<Paren<Option<PropertyListOfArguments>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyActualArg<'a> {
-    PropertyExpr(PropertyExpr<'a>),
-    SequenceActualArg(SequenceActualArg<'a>),
+pub enum PropertyListOfArguments {
+    Ordered(PropertyListOfArgumentsOrdered),
+    Named(PropertyListOfArgumentsNamed),
 }
 
 #[derive(Debug, Node)]
-pub enum AssertionItemDeclaration<'a> {
-    PropertyDeclaration(PropertyDeclaration<'a>),
-    SequenceDeclaration(SequenceDeclaration<'a>),
-    LetDeclaration(LetDeclaration<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyDeclaration<'a> {
+pub struct PropertyListOfArgumentsOrdered {
     pub nodes: (
-        Keyword<'a>,
-        PropertyIdentifier<'a>,
-        Option<Paren<'a, Option<PropertyPortList<'a>>>>,
-        Symbol<'a>,
-        Vec<AssertionVariableDeclaration<'a>>,
-        PropertySpec<'a>,
-        Option<Symbol<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, PropertyIdentifier<'a>)>,
+        List<Symbol, Option<PropertyActualArg>>,
+        Vec<(Symbol, Symbol, Identifier, Paren<Option<PropertyActualArg>>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyPortList<'a> {
-    pub nodes: (List<Symbol<'a>, PropertyPortItem<'a>>,),
+pub struct PropertyListOfArgumentsNamed {
+    pub nodes: (List<Symbol, (Symbol, Identifier, Paren<Option<PropertyActualArg>>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyPortItem<'a> {
+pub enum PropertyActualArg {
+    PropertyExpr(PropertyExpr),
+    SequenceActualArg(SequenceActualArg),
+}
+
+#[derive(Debug, Node)]
+pub enum AssertionItemDeclaration {
+    PropertyDeclaration(PropertyDeclaration),
+    SequenceDeclaration(SequenceDeclaration),
+    LetDeclaration(LetDeclaration),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<(Local<'a>, Option<PropertyLvarPortDirection<'a>>)>,
-        Option<PropertyFormalType<'a>>,
-        FormalPortIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, PropertyActualArg<'a>)>,
+        Keyword,
+        PropertyIdentifier,
+        Option<Paren<Option<PropertyPortList>>>,
+        Symbol,
+        Vec<AssertionVariableDeclaration>,
+        PropertySpec,
+        Option<Symbol>,
+        Keyword,
+        Option<(Symbol, PropertyIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyLvarPortDirection<'a> {
-    Input(Keyword<'a>),
+pub struct PropertyPortList {
+    pub nodes: (List<Symbol, PropertyPortItem>,),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyFormalType<'a> {
-    SequenceFormalType(SequenceFormalType<'a>),
-    Property(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertySpec<'a> {
+pub struct PropertyPortItem {
     pub nodes: (
-        Option<ClockingEvent<'a>>,
-        Option<(Keyword<'a>, Keyword<'a>, Paren<'a, ExpressionOrDist<'a>>)>,
-        PropertyExpr<'a>,
+        Vec<AttributeInstance>,
+        Option<(Local, Option<PropertyLvarPortDirection>)>,
+        Option<PropertyFormalType>,
+        FormalPortIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, PropertyActualArg)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyExpr<'a> {
-    SequenceExpr(SequenceExpr<'a>),
-    Strong(PropertyExprStrong<'a>),
-    Weak(PropertyExprWeak<'a>),
-    Paren(Box<PropertyExprParen<'a>>),
-    Not(Box<PropertyExprNot<'a>>),
-    Or(Box<PropertyExprOr<'a>>),
-    And(Box<PropertyExprAnd<'a>>),
-    ImplicationOverlapped(Box<PropertyExprImplicationOverlapped<'a>>),
-    ImplicationNonoverlapped(Box<PropertyExprImplicationNonoverlapped<'a>>),
-    If(Box<PropertyExprIf<'a>>),
-    Case(Box<PropertyExprCase<'a>>),
-    FollowedByOverlapped(Box<PropertyExprFollowedByOverlapped<'a>>),
-    FollowedByNonoverlapped(Box<PropertyExprFollowedByNonoverlapped<'a>>),
-    Nexttime(Box<PropertyExprNexttime<'a>>),
-    SNexttime(Box<PropertyExprSNexttime<'a>>),
-    Always(Box<PropertyExprAlways<'a>>),
-    SAlways(Box<PropertyExprSAlways<'a>>),
-    Eventually(Box<PropertyExprEventually<'a>>),
-    SEventually(Box<PropertyExprSEventually<'a>>),
-    Until(Box<PropertyExprUntil<'a>>),
-    SUntil(Box<PropertyExprSUntil<'a>>),
-    UntilWith(Box<PropertyExprUntilWith<'a>>),
-    SUntilWith(Box<PropertyExprSUntilWith<'a>>),
-    Implies(Box<PropertyExprImplies<'a>>),
-    Iff(Box<PropertyExprIff<'a>>),
-    AcceptOn(Box<PropertyExprAcceptOn<'a>>),
-    RejectOn(Box<PropertyExprRejectOn<'a>>),
-    SyncAcceptOn(Box<PropertyExprSyncAcceptOn<'a>>),
-    SyncRejectOn(Box<PropertyExprSyncRejectOn<'a>>),
-    PropertyInstance(Box<PropertyInstance<'a>>),
-    ClockingEvent(Box<PropertyExprClockingEvent<'a>>),
+pub enum PropertyLvarPortDirection {
+    Input(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprStrong<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, SequenceExpr<'a>>),
+pub enum PropertyFormalType {
+    SequenceFormalType(SequenceFormalType),
+    Property(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprWeak<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, SequenceExpr<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprParen<'a> {
-    pub nodes: (Paren<'a, SequenceExpr<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprNot<'a> {
-    pub nodes: (Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprOr<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprAnd<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprImplicationOverlapped<'a> {
-    pub nodes: (SequenceExpr<'a>, Symbol<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprImplicationNonoverlapped<'a> {
-    pub nodes: (SequenceExpr<'a>, Symbol<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprIf<'a> {
+pub struct PropertySpec {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyExpr<'a>,
-        Option<(Keyword<'a>, PropertyExpr<'a>)>,
+        Option<ClockingEvent>,
+        Option<(Keyword, Keyword, Paren<ExpressionOrDist>)>,
+        PropertyExpr,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprCase<'a> {
+pub enum PropertyExpr {
+    SequenceExpr(SequenceExpr),
+    Strong(PropertyExprStrong),
+    Weak(PropertyExprWeak),
+    Paren(Box<PropertyExprParen>),
+    Not(Box<PropertyExprNot>),
+    Or(Box<PropertyExprOr>),
+    And(Box<PropertyExprAnd>),
+    ImplicationOverlapped(Box<PropertyExprImplicationOverlapped>),
+    ImplicationNonoverlapped(Box<PropertyExprImplicationNonoverlapped>),
+    If(Box<PropertyExprIf>),
+    Case(Box<PropertyExprCase>),
+    FollowedByOverlapped(Box<PropertyExprFollowedByOverlapped>),
+    FollowedByNonoverlapped(Box<PropertyExprFollowedByNonoverlapped>),
+    Nexttime(Box<PropertyExprNexttime>),
+    SNexttime(Box<PropertyExprSNexttime>),
+    Always(Box<PropertyExprAlways>),
+    SAlways(Box<PropertyExprSAlways>),
+    Eventually(Box<PropertyExprEventually>),
+    SEventually(Box<PropertyExprSEventually>),
+    Until(Box<PropertyExprUntil>),
+    SUntil(Box<PropertyExprSUntil>),
+    UntilWith(Box<PropertyExprUntilWith>),
+    SUntilWith(Box<PropertyExprSUntilWith>),
+    Implies(Box<PropertyExprImplies>),
+    Iff(Box<PropertyExprIff>),
+    AcceptOn(Box<PropertyExprAcceptOn>),
+    RejectOn(Box<PropertyExprRejectOn>),
+    SyncAcceptOn(Box<PropertyExprSyncAcceptOn>),
+    SyncRejectOn(Box<PropertyExprSyncRejectOn>),
+    PropertyInstance(Box<PropertyInstance>),
+    ClockingEvent(Box<PropertyExprClockingEvent>),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprStrong {
+    pub nodes: (Keyword, Paren<SequenceExpr>),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprWeak {
+    pub nodes: (Keyword, Paren<SequenceExpr>),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprParen {
+    pub nodes: (Paren<SequenceExpr>,),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprNot {
+    pub nodes: (Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprOr {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprAnd {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprImplicationOverlapped {
+    pub nodes: (SequenceExpr, Symbol, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprImplicationNonoverlapped {
+    pub nodes: (SequenceExpr, Symbol, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprIf {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyCaseItem<'a>,
-        Vec<PropertyCaseItem<'a>>,
-        Keyword<'a>,
+        Keyword,
+        Paren<ExpressionOrDist>,
+        PropertyExpr,
+        Option<(Keyword, PropertyExpr)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprFollowedByOverlapped<'a> {
-    pub nodes: (SequenceExpr<'a>, Symbol<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprFollowedByNonoverlapped<'a> {
-    pub nodes: (SequenceExpr<'a>, Symbol<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprNexttime<'a> {
+pub struct PropertyExprCase {
     pub nodes: (
-        Keyword<'a>,
-        Option<Bracket<'a, ConstantExpression<'a>>>,
-        PropertyExpr<'a>,
+        Keyword,
+        Paren<ExpressionOrDist>,
+        PropertyCaseItem,
+        Vec<PropertyCaseItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSNexttime<'a> {
+pub struct PropertyExprFollowedByOverlapped {
+    pub nodes: (SequenceExpr, Symbol, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprFollowedByNonoverlapped {
+    pub nodes: (SequenceExpr, Symbol, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprNexttime {
+    pub nodes: (Keyword, Option<Bracket<ConstantExpression>>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSNexttime {
+    pub nodes: (Keyword, Option<Bracket<ConstantExpression>>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprAlways {
     pub nodes: (
-        Keyword<'a>,
-        Option<Bracket<'a, ConstantExpression<'a>>>,
-        PropertyExpr<'a>,
+        Keyword,
+        Option<Bracket<CycleDelayConstRangeExpression>>,
+        PropertyExpr,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprAlways<'a> {
+pub struct PropertyExprSAlways {
     pub nodes: (
-        Keyword<'a>,
-        Option<Bracket<'a, CycleDelayConstRangeExpression<'a>>>,
-        PropertyExpr<'a>,
+        Keyword,
+        Bracket<CycleDelayConstRangeExpression>,
+        PropertyExpr,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSAlways<'a> {
+pub struct PropertyExprEventually {
+    pub nodes: (Keyword, Bracket<ConstantRange>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSEventually {
     pub nodes: (
-        Keyword<'a>,
-        Bracket<'a, CycleDelayConstRangeExpression<'a>>,
-        PropertyExpr<'a>,
+        Keyword,
+        Option<Bracket<CycleDelayConstRangeExpression>>,
+        PropertyExpr,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprEventually<'a> {
+pub struct PropertyExprUntil {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSUntil {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprUntilWith {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSUntilWith {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprImplies {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprIff {
+    pub nodes: (PropertyExpr, Keyword, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprAcceptOn {
+    pub nodes: (Keyword, Paren<ExpressionOrDist>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprRejectOn {
+    pub nodes: (Keyword, Paren<ExpressionOrDist>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSyncAcceptOn {
+    pub nodes: (Keyword, Paren<ExpressionOrDist>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprSyncRejectOn {
+    pub nodes: (Keyword, Paren<ExpressionOrDist>, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyExprClockingEvent {
+    pub nodes: (ClockingEvent, PropertyExpr),
+}
+
+#[derive(Debug, Node)]
+pub enum PropertyCaseItem {
+    Nondefault(PropertyCaseItemNondefault),
+    Default(PropertyCaseItemDefault),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyCaseItemNondefault {
+    pub nodes: (List<Symbol, ExpressionOrDist>, Symbol, PropertyExpr, Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct PropertyCaseItemDefault {
+    pub nodes: (Keyword, Option<Symbol>, PropertyExpr, Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Bracket<'a, ConstantRange<'a>>,
-        PropertyExpr<'a>,
+        Keyword,
+        SequenceIdentifier,
+        Option<Paren<Option<SequencePortList>>>,
+        Symbol,
+        Vec<AssertionVariableDeclaration>,
+        SequenceExpr,
+        Option<Symbol>,
+        Keyword,
+        Option<(Symbol, SequenceIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSEventually<'a> {
+pub struct SequencePortList {
+    pub nodes: (List<Symbol, SequencePortItem>,),
+}
+
+#[derive(Debug, Node)]
+pub struct SequencePortItem {
     pub nodes: (
-        Keyword<'a>,
-        Option<Bracket<'a, CycleDelayConstRangeExpression<'a>>>,
-        PropertyExpr<'a>,
+        Vec<AttributeInstance>,
+        Option<(Local, Option<SequenceLvarPortDirection>)>,
+        Option<SequenceFormalType>,
+        FormalPortIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, SequenceActualArg)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprUntil<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
+pub enum SequenceLvarPortDirection {
+    Input(Keyword),
+    Inout(Keyword),
+    Output(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSUntil<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
+pub enum SequenceFormalType {
+    DataTypeOrImplicit(DataTypeOrImplicit),
+    Sequence(Keyword),
+    Untyped(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprUntilWith<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
+pub enum SequenceExpr {
+    CycleDelayExpr(Box<SequenceExprCycleDelayExpr>),
+    ExprCycleDelayExpr(Box<SequenceExprExprCycleDelayExpr>),
+    Expression(SequenceExprExpression),
+    Instance(Box<SequenceExprInstance>),
+    Paren(Box<SequenceExprParen>),
+    And(Box<SequenceExprAnd>),
+    Intersect(Box<SequenceExprIntersect>),
+    Or(Box<SequenceExprOr>),
+    FirstMatch(Box<SequenceExprFirstMatch>),
+    Throughout(Box<SequenceExprThroughout>),
+    Within(Box<SequenceExprWithin>),
+    ClockingEvent(Box<SequenceExprClockingEvent>),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSUntilWith<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprImplies<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprIff<'a> {
-    pub nodes: (PropertyExpr<'a>, Keyword<'a>, PropertyExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PropertyExprAcceptOn<'a> {
+pub struct SequenceExprCycleDelayExpr {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyExpr<'a>,
+        CycleDelayRange,
+        SequenceExpr,
+        Vec<(CycleDelayRange, SequenceExpr)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprRejectOn<'a> {
+pub struct SequenceExprExprCycleDelayExpr {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyExpr<'a>,
+        SequenceExpr,
+        CycleDelayRange,
+        SequenceExpr,
+        Vec<(CycleDelayRange, SequenceExpr)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSyncAcceptOn<'a> {
+pub struct SequenceExprExpression {
+    pub nodes: (ExpressionOrDist, Option<BooleanAbbrev>),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceExprInstance {
+    pub nodes: (SequenceInstance, Option<SequenceAbbrev>),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceExprParen {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyExpr<'a>,
+        Paren<(SequenceExpr, Vec<(Symbol, SequenceMatchItem)>)>,
+        Option<SequenceAbbrev>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprSyncRejectOn<'a> {
+pub struct SequenceExprAnd {
+    pub nodes: (SequenceExpr, Keyword, SequenceExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceExprIntersect {
+    pub nodes: (SequenceExpr, Keyword, SequenceExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceExprOr {
+    pub nodes: (SequenceExpr, Keyword, SequenceExpr),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceExprFirstMatch {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ExpressionOrDist<'a>>,
-        PropertyExpr<'a>,
+        Keyword,
+        Paren<(SequenceExpr, Vec<(Symbol, SequenceMatchItem)>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyExprClockingEvent<'a> {
-    pub nodes: (ClockingEvent<'a>, PropertyExpr<'a>),
+pub struct SequenceExprThroughout {
+    pub nodes: (ExpressionOrDist, Keyword, SequenceExpr),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyCaseItem<'a> {
-    Nondefault(PropertyCaseItemNondefault<'a>),
-    Default(PropertyCaseItemDefault<'a>),
+pub struct SequenceExprWithin {
+    pub nodes: (SequenceExpr, Keyword, SequenceExpr),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyCaseItemNondefault<'a> {
+pub struct SequenceExprClockingEvent {
+    pub nodes: (ClockingEvent, SequenceExpr),
+}
+
+#[derive(Debug, Node)]
+pub enum CycleDelayRange {
+    Primary(CycleDelayRangePrimary),
+    Expression(CycleDelayRangeExpression),
+    Asterisk(CycleDelayRangeAsterisk),
+    Plus(CycleDelayRangePlus),
+}
+
+#[derive(Debug, Node)]
+pub struct CycleDelayRangePrimary {
+    pub nodes: (Symbol, ConstantPrimary),
+}
+
+#[derive(Debug, Node)]
+pub struct CycleDelayRangeExpression {
+    pub nodes: (Symbol, Bracket<CycleDelayConstRangeExpression>),
+}
+
+#[derive(Debug, Node)]
+pub struct CycleDelayRangeAsterisk {
+    pub nodes: (Symbol, Bracket<Symbol>),
+}
+
+#[derive(Debug, Node)]
+pub struct CycleDelayRangePlus {
+    pub nodes: (Symbol, Bracket<Symbol>),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceMethodCall {
+    pub nodes: (SequenceInstance, Symbol, MethodIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub enum SequenceMatchItem {
+    OperatorAssignment(OperatorAssignment),
+    IncOrDecExpression(IncOrDecExpression),
+    SubroutineCall(SubroutineCall),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceInstance {
     pub nodes: (
-        List<Symbol<'a>, ExpressionOrDist<'a>>,
-        Symbol<'a>,
-        PropertyExpr<'a>,
-        Symbol<'a>,
+        PsOrHierarchicalSequenceIdentifier,
+        Option<Paren<Option<SequenceListOfArguments>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyCaseItemDefault<'a> {
+pub enum SequenceListOfArguments {
+    Ordered(SequenceListOfArgumentsOrdered),
+    Named(SequenceListOfArgumentsNamed),
+}
+
+#[derive(Debug, Node)]
+pub struct SequenceListOfArgumentsOrdered {
     pub nodes: (
-        Keyword<'a>,
-        Option<Symbol<'a>>,
-        PropertyExpr<'a>,
-        Symbol<'a>,
+        List<Symbol, Option<SequenceActualArg>>,
+        Vec<(Symbol, Symbol, Identifier, Paren<Option<SequenceActualArg>>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceDeclaration<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        SequenceIdentifier<'a>,
-        Option<Paren<'a, Option<SequencePortList<'a>>>>,
-        Symbol<'a>,
-        Vec<AssertionVariableDeclaration<'a>>,
-        SequenceExpr<'a>,
-        Option<Symbol<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, SequenceIdentifier<'a>)>,
-    ),
+pub struct SequenceListOfArgumentsNamed {
+    pub nodes: (List<Symbol, (Symbol, Identifier, Paren<Option<SequenceActualArg>>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequencePortList<'a> {
-    pub nodes: (List<Symbol<'a>, SequencePortItem<'a>>,),
+pub enum SequenceActualArg {
+    EventExpression(EventExpression),
+    SequenceExpr(SequenceExpr),
 }
 
 #[derive(Debug, Node)]
-pub struct SequencePortItem<'a> {
-    pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<(Local<'a>, Option<SequenceLvarPortDirection<'a>>)>,
-        Option<SequenceFormalType<'a>>,
-        FormalPortIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, SequenceActualArg<'a>)>,
-    ),
+pub enum BooleanAbbrev {
+    ConsecutiveRepetition(ConsecutiveRepetition),
+    NonConsecutiveRepetition(NonConsecutiveRepetition),
+    GotoRepetition(GotoRepetition),
 }
 
 #[derive(Debug, Node)]
-pub enum SequenceLvarPortDirection<'a> {
-    Input(Keyword<'a>),
-    Inout(Keyword<'a>),
-    Output(Keyword<'a>),
+pub struct SequenceAbbrev {
+    pub nodes: (ConsecutiveRepetition,),
 }
 
 #[derive(Debug, Node)]
-pub enum SequenceFormalType<'a> {
-    DataTypeOrImplicit(DataTypeOrImplicit<'a>),
-    Sequence(Keyword<'a>),
-    Untyped(Keyword<'a>),
+pub enum ConsecutiveRepetition {
+    Expression(ConsecutiveRepetitionExpression),
+    Asterisk(ConsecutiveRepetitionAsterisk),
+    Plus(ConsecutiveRepetitionPlus),
 }
 
 #[derive(Debug, Node)]
-pub enum SequenceExpr<'a> {
-    CycleDelayExpr(Box<SequenceExprCycleDelayExpr<'a>>),
-    ExprCycleDelayExpr(Box<SequenceExprExprCycleDelayExpr<'a>>),
-    Expression(SequenceExprExpression<'a>),
-    Instance(Box<SequenceExprInstance<'a>>),
-    Paren(Box<SequenceExprParen<'a>>),
-    And(Box<SequenceExprAnd<'a>>),
-    Intersect(Box<SequenceExprIntersect<'a>>),
-    Or(Box<SequenceExprOr<'a>>),
-    FirstMatch(Box<SequenceExprFirstMatch<'a>>),
-    Throughout(Box<SequenceExprThroughout<'a>>),
-    Within(Box<SequenceExprWithin<'a>>),
-    ClockingEvent(Box<SequenceExprClockingEvent<'a>>),
+pub struct ConsecutiveRepetitionExpression {
+    pub nodes: (Bracket<(Symbol, ConstOrRangeExpression)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprCycleDelayExpr<'a> {
-    pub nodes: (
-        CycleDelayRange<'a>,
-        SequenceExpr<'a>,
-        Vec<(CycleDelayRange<'a>, SequenceExpr<'a>)>,
-    ),
+pub struct ConsecutiveRepetitionAsterisk {
+    pub nodes: (Bracket<Symbol>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprExprCycleDelayExpr<'a> {
-    pub nodes: (
-        SequenceExpr<'a>,
-        CycleDelayRange<'a>,
-        SequenceExpr<'a>,
-        Vec<(CycleDelayRange<'a>, SequenceExpr<'a>)>,
-    ),
+pub struct ConsecutiveRepetitionPlus {
+    pub nodes: (Bracket<Symbol>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprExpression<'a> {
-    pub nodes: (ExpressionOrDist<'a>, Option<BooleanAbbrev<'a>>),
+pub struct NonConsecutiveRepetition {
+    pub nodes: (Bracket<(Symbol, ConstOrRangeExpression)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprInstance<'a> {
-    pub nodes: (SequenceInstance<'a>, Option<SequenceAbbrev<'a>>),
+pub struct GotoRepetition {
+    pub nodes: (Bracket<(Symbol, ConstOrRangeExpression)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprParen<'a> {
-    pub nodes: (
-        Paren<'a, (SequenceExpr<'a>, Vec<(Symbol<'a>, SequenceMatchItem<'a>)>)>,
-        Option<SequenceAbbrev<'a>>,
-    ),
+pub enum ConstOrRangeExpression {
+    ConstantExpression(ConstantExpression),
+    CycleDelayConstRangeExpression(CycleDelayConstRangeExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprAnd<'a> {
-    pub nodes: (SequenceExpr<'a>, Keyword<'a>, SequenceExpr<'a>),
+pub enum CycleDelayConstRangeExpression {
+    Binary(CycleDelayConstRangeExpressionBinary),
+    Dollar(CycleDelayConstRangeExpressionDollar),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprIntersect<'a> {
-    pub nodes: (SequenceExpr<'a>, Keyword<'a>, SequenceExpr<'a>),
+pub struct CycleDelayConstRangeExpressionBinary {
+    pub nodes: (ConstantExpression, Symbol, ConstantExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprOr<'a> {
-    pub nodes: (SequenceExpr<'a>, Keyword<'a>, SequenceExpr<'a>),
+pub struct CycleDelayConstRangeExpressionDollar {
+    pub nodes: (ConstantExpression, Symbol, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprFirstMatch<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Paren<'a, (SequenceExpr<'a>, Vec<(Symbol<'a>, SequenceMatchItem<'a>)>)>,
-    ),
+pub struct ExpressionOrDist {
+    pub nodes: (Expression, Option<(Keyword, Brace<DistList>)>),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceExprThroughout<'a> {
-    pub nodes: (ExpressionOrDist<'a>, Keyword<'a>, SequenceExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceExprWithin<'a> {
-    pub nodes: (SequenceExpr<'a>, Keyword<'a>, SequenceExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceExprClockingEvent<'a> {
-    pub nodes: (ClockingEvent<'a>, SequenceExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum CycleDelayRange<'a> {
-    Primary(CycleDelayRangePrimary<'a>),
-    Expression(CycleDelayRangeExpression<'a>),
-    Asterisk(CycleDelayRangeAsterisk<'a>),
-    Plus(CycleDelayRangePlus<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayRangePrimary<'a> {
-    pub nodes: (Symbol<'a>, ConstantPrimary<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayRangeExpression<'a> {
-    pub nodes: (Symbol<'a>, Bracket<'a, CycleDelayConstRangeExpression<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayRangeAsterisk<'a> {
-    pub nodes: (Symbol<'a>, Bracket<'a, Symbol<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayRangePlus<'a> {
-    pub nodes: (Symbol<'a>, Bracket<'a, Symbol<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceMethodCall<'a> {
-    pub nodes: (SequenceInstance<'a>, Symbol<'a>, MethodIdentifier<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum SequenceMatchItem<'a> {
-    OperatorAssignment(OperatorAssignment<'a>),
-    IncOrDecExpression(IncOrDecExpression<'a>),
-    SubroutineCall(SubroutineCall<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceInstance<'a> {
-    pub nodes: (
-        PsOrHierarchicalSequenceIdentifier<'a>,
-        Option<Paren<'a, Option<SequenceListOfArguments<'a>>>>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum SequenceListOfArguments<'a> {
-    Ordered(SequenceListOfArgumentsOrdered<'a>),
-    Named(SequenceListOfArgumentsNamed<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceListOfArgumentsOrdered<'a> {
-    pub nodes: (
-        List<Symbol<'a>, Option<SequenceActualArg<'a>>>,
-        Vec<(
-            Symbol<'a>,
-            Symbol<'a>,
-            Identifier<'a>,
-            Paren<'a, Option<SequenceActualArg<'a>>>,
-        )>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceListOfArgumentsNamed<'a> {
-    pub nodes: (
-        List<
-            Symbol<'a>,
-            (
-                Symbol<'a>,
-                Identifier<'a>,
-                Paren<'a, Option<SequenceActualArg<'a>>>,
-            ),
-        >,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum SequenceActualArg<'a> {
-    EventExpression(EventExpression<'a>),
-    SequenceExpr(SequenceExpr<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum BooleanAbbrev<'a> {
-    ConsecutiveRepetition(ConsecutiveRepetition<'a>),
-    NonConsecutiveRepetition(NonConsecutiveRepetition<'a>),
-    GotoRepetition(GotoRepetition<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SequenceAbbrev<'a> {
-    pub nodes: (ConsecutiveRepetition<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub enum ConsecutiveRepetition<'a> {
-    Expression(ConsecutiveRepetitionExpression<'a>),
-    Asterisk(ConsecutiveRepetitionAsterisk<'a>),
-    Plus(ConsecutiveRepetitionPlus<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct ConsecutiveRepetitionExpression<'a> {
-    pub nodes: (Bracket<'a, (Symbol<'a>, ConstOrRangeExpression<'a>)>,),
-}
-
-#[derive(Debug, Node)]
-pub struct ConsecutiveRepetitionAsterisk<'a> {
-    pub nodes: (Bracket<'a, Symbol<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub struct ConsecutiveRepetitionPlus<'a> {
-    pub nodes: (Bracket<'a, Symbol<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub struct NonConsecutiveRepetition<'a> {
-    pub nodes: (Bracket<'a, (Symbol<'a>, ConstOrRangeExpression<'a>)>,),
-}
-
-#[derive(Debug, Node)]
-pub struct GotoRepetition<'a> {
-    pub nodes: (Bracket<'a, (Symbol<'a>, ConstOrRangeExpression<'a>)>,),
-}
-
-#[derive(Debug, Node)]
-pub enum ConstOrRangeExpression<'a> {
-    ConstantExpression(ConstantExpression<'a>),
-    CycleDelayConstRangeExpression(CycleDelayConstRangeExpression<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum CycleDelayConstRangeExpression<'a> {
-    Binary(CycleDelayConstRangeExpressionBinary<'a>),
-    Dollar(CycleDelayConstRangeExpressionDollar<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayConstRangeExpressionBinary<'a> {
-    pub nodes: (ConstantExpression<'a>, Symbol<'a>, ConstantExpression<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CycleDelayConstRangeExpressionDollar<'a> {
-    pub nodes: (ConstantExpression<'a>, Symbol<'a>, Symbol<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct ExpressionOrDist<'a> {
-    pub nodes: (
-        Expression<'a>,
-        Option<(Keyword<'a>, Brace<'a, DistList<'a>>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct AssertionVariableDeclaration<'a> {
-    pub nodes: (
-        VarDataType<'a>,
-        ListOfVariableDeclAssignments<'a>,
-        Symbol<'a>,
-    ),
+pub struct AssertionVariableDeclaration {
+    pub nodes: (VarDataType, ListOfVariableDeclAssignments, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/block_item_declarations.rs b/src/parser/declarations/block_item_declarations.rs
index e820799..7920737 100644
--- a/src/parser/declarations/block_item_declarations.rs
+++ b/src/parser/declarations/block_item_declarations.rs
@@ -7,39 +7,39 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum BlockItemDeclaration<'a> {
-    Data(BlockItemDeclarationData<'a>),
-    LocalParameter(BlockItemDeclarationLocalParameter<'a>),
-    Parameter(BlockItemDeclarationParameter<'a>),
-    Let(BlockItemDeclarationLet<'a>),
+pub enum BlockItemDeclaration {
+    Data(BlockItemDeclarationData),
+    LocalParameter(BlockItemDeclarationLocalParameter),
+    Parameter(BlockItemDeclarationParameter),
+    Let(BlockItemDeclarationLet),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockItemDeclarationData<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, DataDeclaration<'a>),
+pub struct BlockItemDeclarationData {
+    pub nodes: (Vec<AttributeInstance>, DataDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockItemDeclarationLocalParameter<'a> {
+pub struct BlockItemDeclarationLocalParameter {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        LocalParameterDeclaration<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        LocalParameterDeclaration,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockItemDeclarationParameter<'a> {
+pub struct BlockItemDeclarationParameter {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ParameterDeclaration<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        ParameterDeclaration,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockItemDeclarationLet<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, LetDeclaration<'a>),
+pub struct BlockItemDeclarationLet {
+    pub nodes: (Vec<AttributeInstance>, LetDeclaration),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/covergroup_declarations.rs b/src/parser/declarations/covergroup_declarations.rs
index c38d9fc..f71bb78 100644
--- a/src/parser/declarations/covergroup_declarations.rs
+++ b/src/parser/declarations/covergroup_declarations.rs
@@ -9,514 +9,468 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct CovergroupDeclaration<'a> {
+pub struct CovergroupDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        CovergroupIdentifier<'a>,
-        Option<Paren<'a, Option<TfPortList<'a>>>>,
-        Option<CoverageEvent<'a>>,
-        Symbol<'a>,
-        Vec<CoverageSpecOrOption<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, CovergroupIdentifier<'a>)>,
+        Keyword,
+        CovergroupIdentifier,
+        Option<Paren<Option<TfPortList>>>,
+        Option<CoverageEvent>,
+        Symbol,
+        Vec<CoverageSpecOrOption>,
+        Keyword,
+        Option<(Symbol, CovergroupIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CoverageSpecOrOption<'a> {
-    Spec(CoverageSpecOrOptionSpec<'a>),
-    Option(CoverageSpecOrOptionOption<'a>),
+pub enum CoverageSpecOrOption {
+    Spec(CoverageSpecOrOptionSpec),
+    Option(CoverageSpecOrOptionOption),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageSpecOrOptionSpec<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, CoverageSpec<'a>),
+pub struct CoverageSpecOrOptionSpec {
+    pub nodes: (Vec<AttributeInstance>, CoverageSpec),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageSpecOrOptionOption<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, CoverageOption<'a>, Symbol<'a>),
+pub struct CoverageSpecOrOptionOption {
+    pub nodes: (Vec<AttributeInstance>, CoverageOption, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum CoverageOption<'a> {
-    Option(CoverageOptionOption<'a>),
-    TypeOption(CoverageOptionTypeOption<'a>),
+pub enum CoverageOption {
+    Option(CoverageOptionOption),
+    TypeOption(CoverageOptionTypeOption),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageOptionOption<'a> {
+pub struct CoverageOptionOption {
+    pub nodes: (Keyword, Symbol, MemberIdentifier, Symbol, Expression),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverageOptionTypeOption {
     pub nodes: (
-        Keyword<'a>,
-        Symbol<'a>,
-        MemberIdentifier<'a>,
-        Symbol<'a>,
-        Expression<'a>,
+        Keyword,
+        Symbol,
+        MemberIdentifier,
+        Symbol,
+        ConstantExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageOptionTypeOption<'a> {
+pub enum CoverageSpec {
+    CoverPoint(CoverPoint),
+    CoverCross(CoverCross),
+}
+
+#[derive(Debug, Node)]
+pub enum CoverageEvent {
+    ClockingEvent(ClockingEvent),
+    Sample(CoverageEventSample),
+    At(CoverageEventAt),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverageEventSample {
+    pub nodes: (Keyword, Keyword, Keyword, Paren<Option<TfPortList>>),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverageEventAt {
+    pub nodes: (Symbol, Paren<BlockEventExpression>),
+}
+
+#[derive(Debug, Node)]
+pub enum BlockEventExpression {
+    Or(Box<BlockEventExpressionOr>),
+    Begin(BlockEventExpressionBegin),
+    End(BlockEventExpressionEnd),
+}
+
+#[derive(Debug, Node)]
+pub struct BlockEventExpressionOr {
+    pub nodes: (BlockEventExpression, Keyword, BlockEventExpression),
+}
+
+#[derive(Debug, Node)]
+pub struct BlockEventExpressionBegin {
+    pub nodes: (Keyword, HierarchicalBtfIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub struct BlockEventExpressionEnd {
+    pub nodes: (Keyword, HierarchicalBtfIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub enum HierarchicalBtfIdentifier {
+    HierarchicalTfIdentifier(HierarchicalTfIdentifier),
+    HierarchicalBlockIdentifier(HierarchicalBlockIdentifier),
+    Method(HierarchicalBtfIdentifierMethod),
+}
+
+#[derive(Debug, Node)]
+pub struct HierarchicalBtfIdentifierMethod {
+    pub nodes: (Option<HierarchicalIdentifierOrClassScope>, MethodIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub enum HierarchicalIdentifierOrClassScope {
+    HierarchicalIdentifier((HierarchicalIdentifier, Symbol)),
+    ClassScope(ClassScope),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverPoint {
     pub nodes: (
-        Keyword<'a>,
-        Symbol<'a>,
-        MemberIdentifier<'a>,
-        Symbol<'a>,
-        ConstantExpression<'a>,
+        Option<(Option<DataTypeOrImplicit>, CoverPointIdentifier, Symbol)>,
+        Keyword,
+        Expression,
+        Option<(Keyword, Paren<Expression>)>,
+        BinsOrEmpty,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CoverageSpec<'a> {
-    CoverPoint(CoverPoint<'a>),
-    CoverCross(CoverCross<'a>),
+pub enum BinsOrEmpty {
+    NonEmpty(BinsOrEmptyNonEmpty),
+    Empty(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum CoverageEvent<'a> {
-    ClockingEvent(ClockingEvent<'a>),
-    Sample(CoverageEventSample<'a>),
-    At(CoverageEventAt<'a>),
+pub struct BinsOrEmptyNonEmpty {
+    pub nodes: (Brace<(Vec<AttributeInstance>, Vec<(BinsOrOptions, Symbol)>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageEventSample<'a> {
+pub enum BinsOrOptions {
+    CoverageOption(CoverageOption),
+    Covergroup(BinsOrOptionsCovergroup),
+    CoverPoint(BinsOrOptionsCoverPoint),
+    SetCovergroup(BinsOrOptionsSetCovergroup),
+    TransList(BinsOrOptionsTransList),
+    Default(BinsOrOptionsDefault),
+    DefaultSequence(BinsOrOptionsDefaultSequence),
+}
+
+#[derive(Debug, Node)]
+pub struct BinsOrOptionsCovergroup {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Keyword<'a>,
-        Paren<'a, Option<TfPortList<'a>>>,
+        Option<Wildcard>,
+        BinsKeyword,
+        BinIdentifier,
+        Option<Bracket<Option<CovergroupExpression>>>,
+        Symbol,
+        Brace<CovergroupRangeList>,
+        Option<(Keyword, Paren<WithCovergroupExpression>)>,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverageEventAt<'a> {
-    pub nodes: (Symbol<'a>, Paren<'a, BlockEventExpression<'a>>),
+pub struct Wildcard {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub enum BlockEventExpression<'a> {
-    Or(Box<BlockEventExpressionOr<'a>>),
-    Begin(BlockEventExpressionBegin<'a>),
-    End(BlockEventExpressionEnd<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BlockEventExpressionOr<'a> {
+pub struct BinsOrOptionsCoverPoint {
     pub nodes: (
-        BlockEventExpression<'a>,
-        Keyword<'a>,
-        BlockEventExpression<'a>,
+        Option<Wildcard>,
+        BinsKeyword,
+        BinIdentifier,
+        Option<Bracket<Option<CovergroupExpression>>>,
+        Symbol,
+        CoverPointIdentifier,
+        Keyword,
+        Paren<WithCovergroupExpression>,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockEventExpressionBegin<'a> {
-    pub nodes: (Keyword<'a>, HierarchicalBtfIdentifier<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BlockEventExpressionEnd<'a> {
-    pub nodes: (Keyword<'a>, HierarchicalBtfIdentifier<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum HierarchicalBtfIdentifier<'a> {
-    HierarchicalTfIdentifier(HierarchicalTfIdentifier<'a>),
-    HierarchicalBlockIdentifier(HierarchicalBlockIdentifier<'a>),
-    Method(HierarchicalBtfIdentifierMethod<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct HierarchicalBtfIdentifierMethod<'a> {
+pub struct BinsOrOptionsSetCovergroup {
     pub nodes: (
-        Option<HierarchicalIdentifierOrClassScope<'a>>,
-        MethodIdentifier<'a>,
+        Option<Wildcard>,
+        BinsKeyword,
+        BinIdentifier,
+        Option<Bracket<Option<CovergroupExpression>>>,
+        Symbol,
+        SetCovergroupExpression,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum HierarchicalIdentifierOrClassScope<'a> {
-    HierarchicalIdentifier((HierarchicalIdentifier<'a>, Symbol<'a>)),
-    ClassScope(ClassScope<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CoverPoint<'a> {
+pub struct BinsOrOptionsTransList {
     pub nodes: (
-        Option<(
-            Option<DataTypeOrImplicit<'a>>,
-            CoverPointIdentifier<'a>,
-            Symbol<'a>,
-        )>,
-        Keyword<'a>,
-        Expression<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
-        BinsOrEmpty<'a>,
+        Option<Wildcard>,
+        BinsKeyword,
+        BinIdentifier,
+        Option<(Symbol, Symbol)>,
+        Symbol,
+        TransList,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum BinsOrEmpty<'a> {
-    NonEmpty(BinsOrEmptyNonEmpty<'a>),
-    Empty(Symbol<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsOrEmptyNonEmpty<'a> {
+pub struct BinsOrOptionsDefault {
     pub nodes: (
-        Brace<
-            'a,
-            (
-                Vec<AttributeInstance<'a>>,
-                Vec<(BinsOrOptions<'a>, Symbol<'a>)>,
-            ),
-        >,
+        BinsKeyword,
+        BinIdentifier,
+        Option<Bracket<Option<CovergroupExpression>>>,
+        Symbol,
+        Keyword,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum BinsOrOptions<'a> {
-    CoverageOption(CoverageOption<'a>),
-    Covergroup(BinsOrOptionsCovergroup<'a>),
-    CoverPoint(BinsOrOptionsCoverPoint<'a>),
-    SetCovergroup(BinsOrOptionsSetCovergroup<'a>),
-    TransList(BinsOrOptionsTransList<'a>),
-    Default(BinsOrOptionsDefault<'a>),
-    DefaultSequence(BinsOrOptionsDefaultSequence<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsOrOptionsCovergroup<'a> {
+pub struct BinsOrOptionsDefaultSequence {
     pub nodes: (
-        Option<Wildcard<'a>>,
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Option<Bracket<'a, Option<CovergroupExpression<'a>>>>,
-        Symbol<'a>,
-        Brace<'a, CovergroupRangeList<'a>>,
-        Option<(Keyword<'a>, Paren<'a, WithCovergroupExpression<'a>>)>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        BinsKeyword,
+        BinIdentifier,
+        Symbol,
+        Keyword,
+        Keyword,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Wildcard<'a> {
-    pub nodes: (Keyword<'a>,),
+pub enum BinsKeyword {
+    Bins(Keyword),
+    IllegalBins(Keyword),
+    IgnoreBins(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct BinsOrOptionsCoverPoint<'a> {
+pub struct TransList {
+    pub nodes: (List<Symbol, Paren<TransSet>>,),
+}
+
+#[derive(Debug, Node)]
+pub struct TransSet {
+    pub nodes: (List<Symbol, TransRangeList>,),
+}
+
+#[derive(Debug, Node)]
+pub enum TransRangeList {
+    TransItem(TransItem),
+    Asterisk(TransRangeListAsterisk),
+    Arrow(TransRangeListArrow),
+    Equal(TransRangeListEqual),
+}
+
+#[derive(Debug, Node)]
+pub struct TransRangeListAsterisk {
+    pub nodes: (TransItem, Bracket<(Symbol, RepeatRange)>),
+}
+
+#[derive(Debug, Node)]
+pub struct TransRangeListArrow {
+    pub nodes: (TransItem, Bracket<(Symbol, RepeatRange)>),
+}
+
+#[derive(Debug, Node)]
+pub struct TransRangeListEqual {
+    pub nodes: (TransItem, Bracket<(Symbol, RepeatRange)>),
+}
+
+#[derive(Debug, Node)]
+pub struct TransItem {
+    pub nodes: (CovergroupRangeList,),
+}
+
+#[derive(Debug, Node)]
+pub enum RepeatRange {
+    CovergroupExpression(CovergroupExpression),
+    Binary(RepeatRangeBinary),
+}
+
+#[derive(Debug, Node)]
+pub struct RepeatRangeBinary {
+    pub nodes: (CovergroupExpression, Symbol, CovergroupExpression),
+}
+
+#[derive(Debug, Node)]
+pub struct CoverCross {
     pub nodes: (
-        Option<Wildcard<'a>>,
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Option<Bracket<'a, Option<CovergroupExpression<'a>>>>,
-        Symbol<'a>,
-        CoverPointIdentifier<'a>,
-        Keyword<'a>,
-        Paren<'a, WithCovergroupExpression<'a>>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        Option<(CrossIdentifier, Symbol)>,
+        Keyword,
+        ListOfCrossItems,
+        Option<(Keyword, Paren<Expression>)>,
+        CrossBody,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BinsOrOptionsSetCovergroup<'a> {
+pub struct ListOfCrossItems {
+    pub nodes: (CrossItem, List<Symbol, CrossItem>),
+}
+
+#[derive(Debug, Node)]
+pub enum CrossItem {
+    CoverPointIdentifier(CoverPointIdentifier),
+    VariableIdentifier(VariableIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub enum CrossBody {
+    NonEmpty(CrossBodyNonEmpty),
+    Empty(Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct CrossBodyNonEmpty {
+    pub nodes: (Brace<Vec<(CrossBodyItem, Symbol)>>,),
+}
+
+#[derive(Debug, Node)]
+pub enum CrossBodyItem {
+    FunctionDeclaration(FunctionDeclaration),
+    BinsSelectionOrOption((BinsSelectionOrOption, Symbol)),
+}
+
+#[derive(Debug, Node)]
+pub enum BinsSelectionOrOption {
+    Coverage(BinsSelectionOrOptionCoverage),
+    Bins(BinsSelectionOrOptionBins),
+}
+
+#[derive(Debug, Node)]
+pub struct BinsSelectionOrOptionCoverage {
+    pub nodes: (Vec<AttributeInstance>, CoverageOption),
+}
+
+#[derive(Debug, Node)]
+pub struct BinsSelectionOrOptionBins {
+    pub nodes: (Vec<AttributeInstance>, BinsSelection),
+}
+
+#[derive(Debug, Node)]
+pub struct BinsSelection {
     pub nodes: (
-        Option<Wildcard<'a>>,
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Option<Bracket<'a, Option<CovergroupExpression<'a>>>>,
-        Symbol<'a>,
-        SetCovergroupExpression<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        BinsKeyword,
+        BinIdentifier,
+        Symbol,
+        SelectExpression,
+        Option<(Keyword, Paren<Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BinsOrOptionsTransList<'a> {
+pub enum SelectExpression {
+    SelectCondition(SelectCondition),
+    Not(SelectExpressionNot),
+    And(Box<SelectExpressionAnd>),
+    Or(Box<SelectExpressionOr>),
+    Paren(Box<SelectExpressionParen>),
+    With(Box<SelectExpressionWith>),
+    CrossIdentifier(CrossIdentifier),
+    CrossSet(SelectExpressionCrossSet),
+}
+
+#[derive(Debug, Node)]
+pub struct SelectExpressionNot {
+    pub nodes: (Symbol, SelectCondition),
+}
+
+#[derive(Debug, Node)]
+pub struct SelectExpressionAnd {
+    pub nodes: (SelectExpression, Symbol, SelectExpression),
+}
+
+#[derive(Debug, Node)]
+pub struct SelectExpressionOr {
+    pub nodes: (SelectExpression, Symbol, SelectExpression),
+}
+
+#[derive(Debug, Node)]
+pub struct SelectExpressionParen {
+    pub nodes: (Paren<SelectExpression>,),
+}
+
+#[derive(Debug, Node)]
+pub struct SelectExpressionWith {
     pub nodes: (
-        Option<Wildcard<'a>>,
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Option<(Symbol<'a>, Symbol<'a>)>,
-        Symbol<'a>,
-        TransList<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        SelectExpression,
+        Keyword,
+        Paren<WithCovergroupExpression>,
+        Option<(Keyword, IntegerCovergroupExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BinsOrOptionsDefault<'a> {
+pub struct SelectExpressionCrossSet {
     pub nodes: (
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Option<Bracket<'a, Option<CovergroupExpression<'a>>>>,
-        Symbol<'a>,
-        Keyword<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        CrossSetExpression,
+        Option<(Keyword, IntegerCovergroupExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BinsOrOptionsDefaultSequence<'a> {
+pub struct SelectCondition {
     pub nodes: (
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Symbol<'a>,
-        Keyword<'a>,
-        Keyword<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        Keyword,
+        Paren<BinsExpression>,
+        Option<(Keyword, Brace<CovergroupRangeList>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum BinsKeyword<'a> {
-    Bins(Keyword<'a>),
-    IllegalBins(Keyword<'a>),
-    IgnoreBins(Keyword<'a>),
+pub enum BinsExpression {
+    VariableIdentifier(VariableIdentifier),
+    CoverPoint(BinsExpressionCoverPoint),
 }
 
 #[derive(Debug, Node)]
-pub struct TransList<'a> {
-    pub nodes: (List<Symbol<'a>, Paren<'a, TransSet<'a>>>,),
+pub struct BinsExpressionCoverPoint {
+    pub nodes: (CoverPointIdentifier, Option<(Symbol, BinIdentifier)>),
 }
 
 #[derive(Debug, Node)]
-pub struct TransSet<'a> {
-    pub nodes: (List<Symbol<'a>, TransRangeList<'a>>,),
+pub struct CovergroupRangeList {
+    pub nodes: (List<Symbol, CovergroupValueRange>,),
 }
 
 #[derive(Debug, Node)]
-pub enum TransRangeList<'a> {
-    TransItem(TransItem<'a>),
-    Asterisk(TransRangeListAsterisk<'a>),
-    Arrow(TransRangeListArrow<'a>),
-    Equal(TransRangeListEqual<'a>),
+pub enum CovergroupValueRange {
+    CovergroupExpression(CovergroupExpression),
+    Binary(CovergroupValueRangeBinary),
 }
 
 #[derive(Debug, Node)]
-pub struct TransRangeListAsterisk<'a> {
-    pub nodes: (TransItem<'a>, Bracket<'a, (Symbol<'a>, RepeatRange<'a>)>),
+pub struct CovergroupValueRangeBinary {
+    pub nodes: (Bracket<(CovergroupExpression, Symbol, CovergroupExpression)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct TransRangeListArrow<'a> {
-    pub nodes: (TransItem<'a>, Bracket<'a, (Symbol<'a>, RepeatRange<'a>)>),
+pub struct WithCovergroupExpression {
+    pub nodes: (CovergroupExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct TransRangeListEqual<'a> {
-    pub nodes: (TransItem<'a>, Bracket<'a, (Symbol<'a>, RepeatRange<'a>)>),
+pub struct SetCovergroupExpression {
+    pub nodes: (CovergroupExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct TransItem<'a> {
-    pub nodes: (CovergroupRangeList<'a>,),
+pub struct IntegerCovergroupExpression {
+    pub nodes: (CovergroupExpression,),
 }
 
 #[derive(Debug, Node)]
-pub enum RepeatRange<'a> {
-    CovergroupExpression(CovergroupExpression<'a>),
-    Binary(RepeatRangeBinary<'a>),
+pub struct CrossSetExpression {
+    pub nodes: (CovergroupExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct RepeatRangeBinary<'a> {
-    pub nodes: (
-        CovergroupExpression<'a>,
-        Symbol<'a>,
-        CovergroupExpression<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct CoverCross<'a> {
-    pub nodes: (
-        Option<(CrossIdentifier<'a>, Symbol<'a>)>,
-        Keyword<'a>,
-        ListOfCrossItems<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
-        CrossBody<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct ListOfCrossItems<'a> {
-    pub nodes: (CrossItem<'a>, List<Symbol<'a>, CrossItem<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub enum CrossItem<'a> {
-    CoverPointIdentifier(CoverPointIdentifier<'a>),
-    VariableIdentifier(VariableIdentifier<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum CrossBody<'a> {
-    NonEmpty(CrossBodyNonEmpty<'a>),
-    Empty(Symbol<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CrossBodyNonEmpty<'a> {
-    pub nodes: (Brace<'a, Vec<(CrossBodyItem<'a>, Symbol<'a>)>>,),
-}
-
-#[derive(Debug, Node)]
-pub enum CrossBodyItem<'a> {
-    FunctionDeclaration(FunctionDeclaration<'a>),
-    BinsSelectionOrOption((BinsSelectionOrOption<'a>, Symbol<'a>)),
-}
-
-#[derive(Debug, Node)]
-pub enum BinsSelectionOrOption<'a> {
-    Coverage(BinsSelectionOrOptionCoverage<'a>),
-    Bins(BinsSelectionOrOptionBins<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsSelectionOrOptionCoverage<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, CoverageOption<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsSelectionOrOptionBins<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, BinsSelection<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsSelection<'a> {
-    pub nodes: (
-        BinsKeyword<'a>,
-        BinIdentifier<'a>,
-        Symbol<'a>,
-        SelectExpression<'a>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum SelectExpression<'a> {
-    SelectCondition(SelectCondition<'a>),
-    Not(SelectExpressionNot<'a>),
-    And(Box<SelectExpressionAnd<'a>>),
-    Or(Box<SelectExpressionOr<'a>>),
-    Paren(Box<SelectExpressionParen<'a>>),
-    With(Box<SelectExpressionWith<'a>>),
-    CrossIdentifier(CrossIdentifier<'a>),
-    CrossSet(SelectExpressionCrossSet<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionNot<'a> {
-    pub nodes: (Symbol<'a>, SelectCondition<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionAnd<'a> {
-    pub nodes: (SelectExpression<'a>, Symbol<'a>, SelectExpression<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionOr<'a> {
-    pub nodes: (SelectExpression<'a>, Symbol<'a>, SelectExpression<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionParen<'a> {
-    pub nodes: (Paren<'a, SelectExpression<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionWith<'a> {
-    pub nodes: (
-        SelectExpression<'a>,
-        Keyword<'a>,
-        Paren<'a, WithCovergroupExpression<'a>>,
-        Option<(Keyword<'a>, IntegerCovergroupExpression<'a>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectExpressionCrossSet<'a> {
-    pub nodes: (
-        CrossSetExpression<'a>,
-        Option<(Keyword<'a>, IntegerCovergroupExpression<'a>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct SelectCondition<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Paren<'a, BinsExpression<'a>>,
-        Option<(Keyword<'a>, Brace<'a, CovergroupRangeList<'a>>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum BinsExpression<'a> {
-    VariableIdentifier(VariableIdentifier<'a>),
-    CoverPoint(BinsExpressionCoverPoint<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct BinsExpressionCoverPoint<'a> {
-    pub nodes: (
-        CoverPointIdentifier<'a>,
-        Option<(Symbol<'a>, BinIdentifier<'a>)>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct CovergroupRangeList<'a> {
-    pub nodes: (List<Symbol<'a>, CovergroupValueRange<'a>>,),
-}
-
-#[derive(Debug, Node)]
-pub enum CovergroupValueRange<'a> {
-    CovergroupExpression(CovergroupExpression<'a>),
-    Binary(CovergroupValueRangeBinary<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct CovergroupValueRangeBinary<'a> {
-    pub nodes: (
-        Bracket<
-            'a,
-            (
-                CovergroupExpression<'a>,
-                Symbol<'a>,
-                CovergroupExpression<'a>,
-            ),
-        >,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct WithCovergroupExpression<'a> {
-    pub nodes: (CovergroupExpression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct SetCovergroupExpression<'a> {
-    pub nodes: (CovergroupExpression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct IntegerCovergroupExpression<'a> {
-    pub nodes: (CovergroupExpression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct CrossSetExpression<'a> {
-    pub nodes: (CovergroupExpression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct CovergroupExpression<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct CovergroupExpression {
+    pub nodes: (Expression,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/declaration_assignments.rs b/src/parser/declarations/declaration_assignments.rs
index 62d0811..1c71663 100644
--- a/src/parser/declarations/declaration_assignments.rs
+++ b/src/parser/declarations/declaration_assignments.rs
@@ -9,167 +9,140 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct DefparamAssignment<'a> {
+pub struct DefparamAssignment {
     pub nodes: (
-        HierarchicalParameterIdentifier<'a>,
-        Symbol<'a>,
-        ConstantMintypmaxExpression<'a>,
+        HierarchicalParameterIdentifier,
+        Symbol,
+        ConstantMintypmaxExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NetDeclAssignment<'a> {
+pub struct NetDeclAssignment {
     pub nodes: (
-        NetIdentifier<'a>,
-        Vec<UnpackedDimension<'a>>,
-        Option<(Symbol<'a>, Expression<'a>)>,
+        NetIdentifier,
+        Vec<UnpackedDimension>,
+        Option<(Symbol, Expression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParamAssignment<'a> {
+pub struct ParamAssignment {
     pub nodes: (
-        ParameterIdentifier<'a>,
-        Vec<UnpackedDimension<'a>>,
-        Option<(Symbol<'a>, ConstantParamExpression<'a>)>,
+        ParameterIdentifier,
+        Vec<UnpackedDimension>,
+        Option<(Symbol, ConstantParamExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum SpecparamAssignment<'a> {
-    Mintypmax(SpecparamAssignmentMintypmax<'a>),
-    PulseControlSpecparam(PulseControlSpecparam<'a>),
+pub enum SpecparamAssignment {
+    Mintypmax(SpecparamAssignmentMintypmax),
+    PulseControlSpecparam(PulseControlSpecparam),
 }
 
 #[derive(Debug, Node)]
-pub struct SpecparamAssignmentMintypmax<'a> {
+pub struct SpecparamAssignmentMintypmax {
+    pub nodes: (SpecparamIdentifier, Symbol, ConstantMintypmaxExpression),
+}
+
+#[derive(Debug, Node)]
+pub struct TypeAssignment {
+    pub nodes: (TypeIdentifier, Option<(Symbol, DataType)>),
+}
+
+#[derive(Debug, Node)]
+pub enum PulseControlSpecparam {
+    WithoutDescriptor(PulseControlSpecparamWithoutDescriptor),
+    WithDescriptor(PulseControlSpecparamWithDescriptor),
+}
+
+#[derive(Debug, Node)]
+pub struct PulseControlSpecparamWithoutDescriptor {
     pub nodes: (
-        SpecparamIdentifier<'a>,
-        Symbol<'a>,
-        ConstantMintypmaxExpression<'a>,
+        Symbol,
+        Symbol,
+        Paren<(RejectLimitValue, Option<(Symbol, ErrorLimitValue)>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TypeAssignment<'a> {
-    pub nodes: (TypeIdentifier<'a>, Option<(Symbol<'a>, DataType<'a>)>),
-}
-
-#[derive(Debug, Node)]
-pub enum PulseControlSpecparam<'a> {
-    WithoutDescriptor(PulseControlSpecparamWithoutDescriptor<'a>),
-    WithDescriptor(PulseControlSpecparamWithDescriptor<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PulseControlSpecparamWithoutDescriptor<'a> {
+pub struct PulseControlSpecparamWithDescriptor {
     pub nodes: (
-        Symbol<'a>,
-        Symbol<'a>,
-        Paren<
-            'a,
-            (
-                RejectLimitValue<'a>,
-                Option<(Symbol<'a>, ErrorLimitValue<'a>)>,
-            ),
-        >,
+        Symbol,
+        SpecifyInputTerminalDescriptor,
+        Symbol,
+        SpecifyOutputTerminalDescriptor,
+        Symbol,
+        Paren<(RejectLimitValue, Option<(Symbol, ErrorLimitValue)>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PulseControlSpecparamWithDescriptor<'a> {
+pub struct ErrorLimitValue {
+    pub nodes: (LimitValue,),
+}
+
+#[derive(Debug, Node)]
+pub struct RejectLimitValue {
+    pub nodes: (LimitValue,),
+}
+
+#[derive(Debug, Node)]
+pub struct LimitValue {
+    pub nodes: (ConstantMintypmaxExpression,),
+}
+
+#[derive(Debug, Node)]
+pub enum VariableDeclAssignment {
+    Variable(VariableDeclAssignmentVariable),
+    DynamicArray(VariableDeclAssignmentDynamicArray),
+    Class(VariableDeclAssignmentClass),
+}
+
+#[derive(Debug, Node)]
+pub struct VariableDeclAssignmentVariable {
     pub nodes: (
-        Symbol<'a>,
-        SpecifyInputTerminalDescriptor<'a>,
-        Symbol<'a>,
-        SpecifyOutputTerminalDescriptor<'a>,
-        Symbol<'a>,
-        Paren<
-            'a,
-            (
-                RejectLimitValue<'a>,
-                Option<(Symbol<'a>, ErrorLimitValue<'a>)>,
-            ),
-        >,
+        VariableIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, Expression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ErrorLimitValue<'a> {
-    pub nodes: (LimitValue<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct RejectLimitValue<'a> {
-    pub nodes: (LimitValue<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct LimitValue<'a> {
-    pub nodes: (ConstantMintypmaxExpression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub enum VariableDeclAssignment<'a> {
-    Variable(VariableDeclAssignmentVariable<'a>),
-    DynamicArray(VariableDeclAssignmentDynamicArray<'a>),
-    Class(VariableDeclAssignmentClass<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct VariableDeclAssignmentVariable<'a> {
+pub struct VariableDeclAssignmentDynamicArray {
     pub nodes: (
-        VariableIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, Expression<'a>)>,
+        DynamicArrayVariableIdentifier,
+        UnsizedDimension,
+        Vec<VariableDimension>,
+        Option<(Symbol, DynamicArrayNew)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableDeclAssignmentDynamicArray<'a> {
-    pub nodes: (
-        DynamicArrayVariableIdentifier<'a>,
-        UnsizedDimension<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, DynamicArrayNew<'a>)>,
-    ),
+pub struct VariableDeclAssignmentClass {
+    pub nodes: (ClassVariableIdentifier, Option<(Symbol, ClassNew)>),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableDeclAssignmentClass<'a> {
-    pub nodes: (
-        ClassVariableIdentifier<'a>,
-        Option<(Symbol<'a>, ClassNew<'a>)>,
-    ),
+pub enum ClassNew {
+    Argument(ClassNewArgument),
+    Expression(ClassNewExpression),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassNew<'a> {
-    Argument(ClassNewArgument<'a>),
-    Expression(ClassNewExpression<'a>),
+pub struct ClassNewArgument {
+    pub nodes: (Option<ClassScope>, Keyword, Option<Paren<ListOfArguments>>),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassNewArgument<'a> {
-    pub nodes: (
-        Option<ClassScope<'a>>,
-        Keyword<'a>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
-    ),
+pub struct ClassNewExpression {
+    pub nodes: (Keyword, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassNewExpression<'a> {
-    pub nodes: (Keyword<'a>, Expression<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct DynamicArrayNew<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Bracket<'a, Expression<'a>>,
-        Option<Paren<'a, Expression<'a>>>,
-    ),
+pub struct DynamicArrayNew {
+    pub nodes: (Keyword, Bracket<Expression>, Option<Paren<Expression>>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/declaration_lists.rs b/src/parser/declarations/declaration_lists.rs
index 7692de7..2320fe2 100644
--- a/src/parser/declarations/declaration_lists.rs
+++ b/src/parser/declarations/declaration_lists.rs
@@ -8,83 +8,83 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ListOfDefparamAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, DefparamAssignment<'a>>,),
+pub struct ListOfDefparamAssignments {
+    pub nodes: (List<Symbol, DefparamAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfGenvarIdentifiers<'a> {
-    pub nodes: (List<Symbol<'a>, GenvarIdentifier<'a>>,),
+pub struct ListOfGenvarIdentifiers {
+    pub nodes: (List<Symbol, GenvarIdentifier>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfInterfaceIdentifiers<'a> {
-    pub nodes: (List<Symbol<'a>, (InterfaceIdentifier<'a>, Vec<UnpackedDimension<'a>>)>,),
+pub struct ListOfInterfaceIdentifiers {
+    pub nodes: (List<Symbol, (InterfaceIdentifier, Vec<UnpackedDimension>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfNetDeclAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, NetDeclAssignment<'a>>,),
+pub struct ListOfNetDeclAssignments {
+    pub nodes: (List<Symbol, NetDeclAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfParamAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, ParamAssignment<'a>>,),
+pub struct ListOfParamAssignments {
+    pub nodes: (List<Symbol, ParamAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPortIdentifiers<'a> {
-    pub nodes: (List<Symbol<'a>, (PortIdentifier<'a>, Vec<UnpackedDimension<'a>>)>,),
+pub struct ListOfPortIdentifiers {
+    pub nodes: (List<Symbol, (PortIdentifier, Vec<UnpackedDimension>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfUdpPortIdentifiers<'a> {
-    pub nodes: (List<Symbol<'a>, PortIdentifier<'a>>,),
+pub struct ListOfUdpPortIdentifiers {
+    pub nodes: (List<Symbol, PortIdentifier>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfSpecparamAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, SpecparamAssignment<'a>>,),
+pub struct ListOfSpecparamAssignments {
+    pub nodes: (List<Symbol, SpecparamAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfTfVariableIdentifiers<'a> {
+pub struct ListOfTfVariableIdentifiers {
     pub nodes: (
         List<
-            Symbol<'a>,
+            Symbol,
             (
-                PortIdentifier<'a>,
-                Vec<VariableDimension<'a>>,
-                Option<(Symbol<'a>, Expression<'a>)>,
+                PortIdentifier,
+                Vec<VariableDimension>,
+                Option<(Symbol, Expression)>,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfTypeAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, TypeAssignment<'a>>,),
+pub struct ListOfTypeAssignments {
+    pub nodes: (List<Symbol, TypeAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfVariableDeclAssignments<'a> {
-    pub nodes: (List<Symbol<'a>, VariableDeclAssignment<'a>>,),
+pub struct ListOfVariableDeclAssignments {
+    pub nodes: (List<Symbol, VariableDeclAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfVariableIdentifiers<'a> {
-    pub nodes: (List<Symbol<'a>, (VariableIdentifier<'a>, Vec<VariableDimension<'a>>)>,),
+pub struct ListOfVariableIdentifiers {
+    pub nodes: (List<Symbol, (VariableIdentifier, Vec<VariableDimension>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfVariablePortIdentifiers<'a> {
+pub struct ListOfVariablePortIdentifiers {
     pub nodes: (
         List<
-            Symbol<'a>,
+            Symbol,
             (
-                PortIdentifier<'a>,
-                Vec<VariableDimension<'a>>,
-                Option<(Symbol<'a>, ConstantExpression<'a>)>,
+                PortIdentifier,
+                Vec<VariableDimension>,
+                Option<(Symbol, ConstantExpression)>,
             ),
         >,
     ),
diff --git a/src/parser/declarations/declaration_ranges.rs b/src/parser/declarations/declaration_ranges.rs
index 60fdf03..593d5a0 100644
--- a/src/parser/declarations/declaration_ranges.rs
+++ b/src/parser/declarations/declaration_ranges.rs
@@ -8,64 +8,64 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum UnpackedDimension<'a> {
-    Range(UnpackedDimensionRange<'a>),
-    Expression(UnpackedDimensionExpression<'a>),
+pub enum UnpackedDimension {
+    Range(UnpackedDimensionRange),
+    Expression(UnpackedDimensionExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct UnpackedDimensionRange<'a> {
-    pub nodes: (Bracket<'a, ConstantRange<'a>>,),
+pub struct UnpackedDimensionRange {
+    pub nodes: (Bracket<ConstantRange>,),
 }
 
 #[derive(Debug, Node)]
-pub struct UnpackedDimensionExpression<'a> {
-    pub nodes: (Bracket<'a, ConstantExpression<'a>>,),
+pub struct UnpackedDimensionExpression {
+    pub nodes: (Bracket<ConstantExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub enum PackedDimension<'a> {
-    Range(PackedDimensionRange<'a>),
-    UnsizedDimension(UnsizedDimension<'a>),
+pub enum PackedDimension {
+    Range(PackedDimensionRange),
+    UnsizedDimension(UnsizedDimension),
 }
 
 #[derive(Debug, Node)]
-pub struct PackedDimensionRange<'a> {
-    pub nodes: (Bracket<'a, ConstantRange<'a>>,),
+pub struct PackedDimensionRange {
+    pub nodes: (Bracket<ConstantRange>,),
 }
 
 #[derive(Debug, Node)]
-pub enum AssociativeDimension<'a> {
-    DataType(AssociativeDimensionDataType<'a>),
-    Asterisk(AssociativeDimensionAsterisk<'a>),
+pub enum AssociativeDimension {
+    DataType(AssociativeDimensionDataType),
+    Asterisk(AssociativeDimensionAsterisk),
 }
 
 #[derive(Debug, Node)]
-pub struct AssociativeDimensionDataType<'a> {
-    pub nodes: (Bracket<'a, DataType<'a>>,),
+pub struct AssociativeDimensionDataType {
+    pub nodes: (Bracket<DataType>,),
 }
 
 #[derive(Debug, Node)]
-pub struct AssociativeDimensionAsterisk<'a> {
-    pub nodes: (Bracket<'a, Symbol<'a>>,),
+pub struct AssociativeDimensionAsterisk {
+    pub nodes: (Bracket<Symbol>,),
 }
 
 #[derive(Debug, Node)]
-pub enum VariableDimension<'a> {
-    UnsizedDimension(UnsizedDimension<'a>),
-    UnpackedDimension(UnpackedDimension<'a>),
-    AssociativeDimension(AssociativeDimension<'a>),
-    QueueDimension(QueueDimension<'a>),
+pub enum VariableDimension {
+    UnsizedDimension(UnsizedDimension),
+    UnpackedDimension(UnpackedDimension),
+    AssociativeDimension(AssociativeDimension),
+    QueueDimension(QueueDimension),
 }
 
 #[derive(Debug, Node)]
-pub struct QueueDimension<'a> {
-    pub nodes: (Bracket<'a, (Symbol<'a>, Option<(Symbol<'a>, ConstantExpression<'a>)>)>,),
+pub struct QueueDimension {
+    pub nodes: (Bracket<(Symbol, Option<(Symbol, ConstantExpression)>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct UnsizedDimension<'a> {
-    pub nodes: (Symbol<'a>, Symbol<'a>),
+pub struct UnsizedDimension {
+    pub nodes: (Symbol, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/delays.rs b/src/parser/declarations/delays.rs
index d819027..9eeefa0 100644
--- a/src/parser/declarations/delays.rs
+++ b/src/parser/declarations/delays.rs
@@ -8,66 +8,57 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum Delay3<'a> {
-    Single(Delay3Single<'a>),
-    Mintypmax(Delay3Mintypmax<'a>),
+pub enum Delay3 {
+    Single(Delay3Single),
+    Mintypmax(Delay3Mintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct Delay3Single<'a> {
-    pub nodes: (Symbol<'a>, DelayValue<'a>),
+pub struct Delay3Single {
+    pub nodes: (Symbol, DelayValue),
 }
 
 #[derive(Debug, Node)]
-pub struct Delay3Mintypmax<'a> {
+pub struct Delay3Mintypmax {
     pub nodes: (
-        Symbol<'a>,
-        Paren<
-            'a,
-            (
-                MintypmaxExpression<'a>,
-                Option<(
-                    Symbol<'a>,
-                    MintypmaxExpression<'a>,
-                    Option<(Symbol<'a>, MintypmaxExpression<'a>)>,
-                )>,
-            ),
-        >,
+        Symbol,
+        Paren<(
+            MintypmaxExpression,
+            Option<(
+                Symbol,
+                MintypmaxExpression,
+                Option<(Symbol, MintypmaxExpression)>,
+            )>,
+        )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum Delay2<'a> {
-    Single(Delay2Single<'a>),
-    Mintypmax(Delay2Mintypmax<'a>),
+pub enum Delay2 {
+    Single(Delay2Single),
+    Mintypmax(Delay2Mintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct Delay2Single<'a> {
-    pub nodes: (Symbol<'a>, DelayValue<'a>),
+pub struct Delay2Single {
+    pub nodes: (Symbol, DelayValue),
 }
 
 #[derive(Debug, Node)]
-pub struct Delay2Mintypmax<'a> {
+pub struct Delay2Mintypmax {
     pub nodes: (
-        Symbol<'a>,
-        Paren<
-            'a,
-            (
-                MintypmaxExpression<'a>,
-                Option<(Symbol<'a>, MintypmaxExpression<'a>)>,
-            ),
-        >,
+        Symbol,
+        Paren<(MintypmaxExpression, Option<(Symbol, MintypmaxExpression)>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum DelayValue<'a> {
-    UnsignedNumber(UnsignedNumber<'a>),
-    RealNumber(RealNumber<'a>),
-    PsIdentifier(PsIdentifier<'a>),
-    TimeLiteral(TimeLiteral<'a>),
-    Step1(Keyword<'a>),
+pub enum DelayValue {
+    UnsignedNumber(UnsignedNumber),
+    RealNumber(RealNumber),
+    PsIdentifier(PsIdentifier),
+    TimeLiteral(TimeLiteral),
+    Step1(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/function_declarations.rs b/src/parser/declarations/function_declarations.rs
index f4db4c6..eb22b97 100644
--- a/src/parser/declarations/function_declarations.rs
+++ b/src/parser/declarations/function_declarations.rs
@@ -9,152 +9,148 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum FunctionDataTypeOrImplicit<'a> {
-    DataTypeOrVoid(DataTypeOrVoid<'a>),
-    ImplicitDataType(ImplicitDataType<'a>),
+pub enum FunctionDataTypeOrImplicit {
+    DataTypeOrVoid(DataTypeOrVoid),
+    ImplicitDataType(ImplicitDataType),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionDeclaration<'a> {
+pub struct FunctionDeclaration {
+    pub nodes: (Keyword, Option<Lifetime>, FunctionBodyDeclaration),
+}
+
+#[derive(Debug, Node)]
+pub enum FunctionBodyDeclaration {
+    WithoutPort(FunctionBodyDeclarationWithoutPort),
+    WithPort(FunctionBodyDeclarationWithPort),
+}
+
+#[derive(Debug, Node)]
+pub struct FunctionBodyDeclarationWithoutPort {
     pub nodes: (
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        FunctionBodyDeclaration<'a>,
+        Option<FunctionDataTypeOrImplicit>,
+        Option<InterfaceIdentifierOrClassScope>,
+        FunctionIdentifier,
+        Symbol,
+        Vec<TfItemDeclaration>,
+        Vec<FunctionStatementOrNull>,
+        Keyword,
+        Option<(Symbol, FunctionIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum FunctionBodyDeclaration<'a> {
-    WithoutPort(FunctionBodyDeclarationWithoutPort<'a>),
-    WithPort(FunctionBodyDeclarationWithPort<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct FunctionBodyDeclarationWithoutPort<'a> {
+pub struct FunctionBodyDeclarationWithPort {
     pub nodes: (
-        Option<FunctionDataTypeOrImplicit<'a>>,
-        Option<InterfaceIdentifierOrClassScope<'a>>,
-        FunctionIdentifier<'a>,
-        Symbol<'a>,
-        Vec<TfItemDeclaration<'a>>,
-        Vec<FunctionStatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, FunctionIdentifier<'a>)>,
+        Option<FunctionDataTypeOrImplicit>,
+        Option<InterfaceIdentifierOrClassScope>,
+        FunctionIdentifier,
+        Paren<Option<TfPortList>>,
+        Symbol,
+        Vec<BlockItemDeclaration>,
+        Vec<FunctionStatementOrNull>,
+        Keyword,
+        Option<(Symbol, FunctionIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionBodyDeclarationWithPort<'a> {
+pub enum InterfaceIdentifierOrClassScope {
+    InterfaceIdentifier((InterfaceIdentifier, Symbol)),
+    ClassScope(ClassScope),
+}
+
+#[derive(Debug, Node)]
+pub struct FunctionPrototype {
     pub nodes: (
-        Option<FunctionDataTypeOrImplicit<'a>>,
-        Option<InterfaceIdentifierOrClassScope<'a>>,
-        FunctionIdentifier<'a>,
-        Paren<'a, Option<TfPortList<'a>>>,
-        Symbol<'a>,
-        Vec<BlockItemDeclaration<'a>>,
-        Vec<FunctionStatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, FunctionIdentifier<'a>)>,
+        Keyword,
+        DataTypeOrVoid,
+        FunctionIdentifier,
+        Option<Paren<Option<TfPortList>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum InterfaceIdentifierOrClassScope<'a> {
-    InterfaceIdentifier((InterfaceIdentifier<'a>, Symbol<'a>)),
-    ClassScope(ClassScope<'a>),
+pub enum DpiImportExport {
+    ImportFunction(DpiImportExportImportFunction),
+    ImportTask(DpiImportExportImportTask),
+    ExportFunction(DpiImportExportExportFunction),
+    ExportTask(DpiImportExportExportTask),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionPrototype<'a> {
+pub struct DpiImportExportImportFunction {
     pub nodes: (
-        Keyword<'a>,
-        DataTypeOrVoid<'a>,
-        FunctionIdentifier<'a>,
-        Option<Paren<'a, Option<TfPortList<'a>>>>,
+        Keyword,
+        DpiSpecString,
+        Option<DpiFunctionImportProperty>,
+        Option<(CIdentifier, Symbol)>,
+        DpiFunctionProto,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum DpiImportExport<'a> {
-    ImportFunction(DpiImportExportImportFunction<'a>),
-    ImportTask(DpiImportExportImportTask<'a>),
-    ExportFunction(DpiImportExportExportFunction<'a>),
-    ExportTask(DpiImportExportExportTask<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct DpiImportExportImportFunction<'a> {
+pub struct DpiImportExportImportTask {
     pub nodes: (
-        Keyword<'a>,
-        DpiSpecString<'a>,
-        Option<DpiFunctionImportProperty<'a>>,
-        Option<(CIdentifier<'a>, Symbol<'a>)>,
-        DpiFunctionProto<'a>,
-        Symbol<'a>,
+        Keyword,
+        DpiSpecString,
+        Option<DpiTaskImportProperty>,
+        Option<(CIdentifier, Symbol)>,
+        DpiTaskProto,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DpiImportExportImportTask<'a> {
+pub struct DpiImportExportExportFunction {
     pub nodes: (
-        Keyword<'a>,
-        DpiSpecString<'a>,
-        Option<DpiTaskImportProperty<'a>>,
-        Option<(CIdentifier<'a>, Symbol<'a>)>,
-        DpiTaskProto<'a>,
-        Symbol<'a>,
+        Keyword,
+        DpiSpecString,
+        Option<(CIdentifier, Symbol)>,
+        Keyword,
+        FunctionIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DpiImportExportExportFunction<'a> {
+pub struct DpiImportExportExportTask {
     pub nodes: (
-        Keyword<'a>,
-        DpiSpecString<'a>,
-        Option<(CIdentifier<'a>, Symbol<'a>)>,
-        Keyword<'a>,
-        FunctionIdentifier<'a>,
-        Symbol<'a>,
+        Keyword,
+        DpiSpecString,
+        Option<(CIdentifier, Symbol)>,
+        Keyword,
+        TaskIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DpiImportExportExportTask<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        DpiSpecString<'a>,
-        Option<(CIdentifier<'a>, Symbol<'a>)>,
-        Keyword<'a>,
-        TaskIdentifier<'a>,
-        Symbol<'a>,
-    ),
+pub enum DpiSpecString {
+    DpiC(Keyword),
+    Dpi(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum DpiSpecString<'a> {
-    DpiC(Keyword<'a>),
-    Dpi(Keyword<'a>),
+pub enum DpiFunctionImportProperty {
+    Context(Keyword),
+    Pure(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum DpiFunctionImportProperty<'a> {
-    Context(Keyword<'a>),
-    Pure(Keyword<'a>),
+pub enum DpiTaskImportProperty {
+    Context(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum DpiTaskImportProperty<'a> {
-    Context(Keyword<'a>),
+pub struct DpiFunctionProto {
+    pub nodes: (FunctionPrototype,),
 }
 
 #[derive(Debug, Node)]
-pub struct DpiFunctionProto<'a> {
-    pub nodes: (FunctionPrototype<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct DpiTaskProto<'a> {
-    pub nodes: (TaskPrototype<'a>,),
+pub struct DpiTaskProto {
+    pub nodes: (TaskPrototype,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/interface_declarations.rs b/src/parser/declarations/interface_declarations.rs
index 59560b2..3d8d673 100644
--- a/src/parser/declarations/interface_declarations.rs
+++ b/src/parser/declarations/interface_declarations.rs
@@ -8,88 +8,81 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ModportDeclaration<'a> {
-    pub nodes: (Keyword<'a>, List<Symbol<'a>, ModportItem<'a>>, Symbol<'a>),
+pub struct ModportDeclaration {
+    pub nodes: (Keyword, List<Symbol, ModportItem>, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportItem<'a> {
+pub struct ModportItem {
     pub nodes: (
-        ModportIdentifier<'a>,
-        Paren<'a, List<Symbol<'a>, ModportPortsDeclaraton<'a>>>,
+        ModportIdentifier,
+        Paren<List<Symbol, ModportPortsDeclaraton>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ModportPortsDeclaraton<'a> {
-    Simple(ModportPortsDeclaratonSimple<'a>),
-    Tf(ModportPortsDeclaratonTf<'a>),
-    Clocking(ModportPortsDeclaratonClocking<'a>),
+pub enum ModportPortsDeclaraton {
+    Simple(ModportPortsDeclaratonSimple),
+    Tf(ModportPortsDeclaratonTf),
+    Clocking(ModportPortsDeclaratonClocking),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportPortsDeclaratonSimple<'a> {
-    pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ModportSimplePortsDeclaration<'a>,
-    ),
+pub struct ModportPortsDeclaratonSimple {
+    pub nodes: (Vec<AttributeInstance>, ModportSimplePortsDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportPortsDeclaratonTf<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ModportTfPortsDeclaration<'a>),
+pub struct ModportPortsDeclaratonTf {
+    pub nodes: (Vec<AttributeInstance>, ModportTfPortsDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportPortsDeclaratonClocking<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ModportClockingDeclaration<'a>),
+pub struct ModportPortsDeclaratonClocking {
+    pub nodes: (Vec<AttributeInstance>, ModportClockingDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportClockingDeclaration<'a> {
-    pub nodes: (Keyword<'a>, ClockingIdentifier<'a>),
+pub struct ModportClockingDeclaration {
+    pub nodes: (Keyword, ClockingIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportSimplePortsDeclaration<'a> {
-    pub nodes: (PortDirection<'a>, List<Symbol<'a>, ModportSimplePort<'a>>),
+pub struct ModportSimplePortsDeclaration {
+    pub nodes: (PortDirection, List<Symbol, ModportSimplePort>),
 }
 
 #[derive(Debug, Node)]
-pub enum ModportSimplePort<'a> {
-    Ordered(ModportSimplePortOrdered<'a>),
-    Named(ModportSimplePortNamed<'a>),
+pub enum ModportSimplePort {
+    Ordered(ModportSimplePortOrdered),
+    Named(ModportSimplePortNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportSimplePortOrdered<'a> {
-    pub nodes: (PortIdentifier<'a>,),
+pub struct ModportSimplePortOrdered {
+    pub nodes: (PortIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportSimplePortNamed<'a> {
-    pub nodes: (
-        Symbol<'a>,
-        PortIdentifier<'a>,
-        Paren<'a, Option<Expression<'a>>>,
-    ),
+pub struct ModportSimplePortNamed {
+    pub nodes: (Symbol, PortIdentifier, Paren<Option<Expression>>),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportTfPortsDeclaration<'a> {
-    pub nodes: (ImportExport<'a>, List<Symbol<'a>, ModportTfPort<'a>>),
+pub struct ModportTfPortsDeclaration {
+    pub nodes: (ImportExport, List<Symbol, ModportTfPort>),
 }
 
 #[derive(Debug, Node)]
-pub enum ModportTfPort<'a> {
-    MethodPrototype(MethodPrototype<'a>),
-    TfIdentifier(TfIdentifier<'a>),
+pub enum ModportTfPort {
+    MethodPrototype(MethodPrototype),
+    TfIdentifier(TfIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum ImportExport<'a> {
-    Import(Keyword<'a>),
-    Export(Keyword<'a>),
+pub enum ImportExport {
+    Import(Keyword),
+    Export(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/let_declarations.rs b/src/parser/declarations/let_declarations.rs
index 6a3d6c9..ddc42e3 100644
--- a/src/parser/declarations/let_declarations.rs
+++ b/src/parser/declarations/let_declarations.rs
@@ -9,89 +9,75 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct LetDeclaration<'a> {
+pub struct LetDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        LetIdentifier<'a>,
-        Option<Paren<'a, Option<LetPortList<'a>>>>,
-        Symbol<'a>,
-        Expression<'a>,
-        Symbol<'a>,
+        Keyword,
+        LetIdentifier,
+        Option<Paren<Option<LetPortList>>>,
+        Symbol,
+        Expression,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LetIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct LetIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct LetPortList<'a> {
-    pub nodes: (List<Symbol<'a>, LetPortItem<'a>>,),
+pub struct LetPortList {
+    pub nodes: (List<Symbol, LetPortItem>,),
 }
 
 #[derive(Debug, Node)]
-pub struct LetPortItem<'a> {
+pub struct LetPortItem {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<LetFormalType<'a>>,
-        FormalPortIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, Expression<'a>)>,
+        Vec<AttributeInstance>,
+        Option<LetFormalType>,
+        FormalPortIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, Expression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum LetFormalType<'a> {
-    DataTypeOrImplicit(DataTypeOrImplicit<'a>),
-    Untyped(Keyword<'a>),
+pub enum LetFormalType {
+    DataTypeOrImplicit(DataTypeOrImplicit),
+    Untyped(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct LetExpression<'a> {
+pub struct LetExpression {
     pub nodes: (
-        Option<PackageScope<'a>>,
-        LetIdentifier<'a>,
-        Option<Paren<'a, Option<LetListOfArguments<'a>>>>,
+        Option<PackageScope>,
+        LetIdentifier,
+        Option<Paren<Option<LetListOfArguments>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum LetListOfArguments<'a> {
-    Ordered(LetListOfArgumentsOrdered<'a>),
-    Named(LetListOfArgumentsNamed<'a>),
+pub enum LetListOfArguments {
+    Ordered(LetListOfArgumentsOrdered),
+    Named(LetListOfArgumentsNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct LetListOfArgumentsOrdered<'a> {
+pub struct LetListOfArgumentsOrdered {
     pub nodes: (
-        List<Symbol<'a>, Option<LetActualArg<'a>>>,
-        Vec<(
-            Symbol<'a>,
-            Symbol<'a>,
-            Identifier<'a>,
-            Paren<'a, Option<LetActualArg<'a>>>,
-        )>,
+        List<Symbol, Option<LetActualArg>>,
+        Vec<(Symbol, Symbol, Identifier, Paren<Option<LetActualArg>>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LetListOfArgumentsNamed<'a> {
-    pub nodes: (
-        List<
-            Symbol<'a>,
-            (
-                Symbol<'a>,
-                Identifier<'a>,
-                Paren<'a, Option<LetActualArg<'a>>>,
-            ),
-        >,
-    ),
+pub struct LetListOfArgumentsNamed {
+    pub nodes: (List<Symbol, (Symbol, Identifier, Paren<Option<LetActualArg>>)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct LetActualArg<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct LetActualArg {
+    pub nodes: (Expression,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/module_parameter_declarations.rs b/src/parser/declarations/module_parameter_declarations.rs
index b37d3b2..fcb0280 100644
--- a/src/parser/declarations/module_parameter_declarations.rs
+++ b/src/parser/declarations/module_parameter_declarations.rs
@@ -7,52 +7,52 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum LocalParameterDeclaration<'a> {
-    Param(LocalParameterDeclarationParam<'a>),
-    Type(LocalParameterDeclarationType<'a>),
+pub enum LocalParameterDeclaration {
+    Param(LocalParameterDeclarationParam),
+    Type(LocalParameterDeclarationType),
 }
 
 #[derive(Debug, Node)]
-pub struct LocalParameterDeclarationParam<'a> {
+pub struct LocalParameterDeclarationParam {
     pub nodes: (
-        Keyword<'a>,
-        Option<DataTypeOrImplicit<'a>>,
-        ListOfParamAssignments<'a>,
+        Keyword,
+        Option<DataTypeOrImplicit>,
+        ListOfParamAssignments,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LocalParameterDeclarationType<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, ListOfTypeAssignments<'a>),
+pub struct LocalParameterDeclarationType {
+    pub nodes: (Keyword, Keyword, ListOfTypeAssignments),
 }
 
 #[derive(Debug, Node)]
-pub enum ParameterDeclaration<'a> {
-    Param(ParameterDeclarationParam<'a>),
-    Type(ParameterDeclarationType<'a>),
+pub enum ParameterDeclaration {
+    Param(ParameterDeclarationParam),
+    Type(ParameterDeclarationType),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterDeclarationParam<'a> {
+pub struct ParameterDeclarationParam {
     pub nodes: (
-        Keyword<'a>,
-        Option<DataTypeOrImplicit<'a>>,
-        ListOfParamAssignments<'a>,
+        Keyword,
+        Option<DataTypeOrImplicit>,
+        ListOfParamAssignments,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterDeclarationType<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, ListOfTypeAssignments<'a>),
+pub struct ParameterDeclarationType {
+    pub nodes: (Keyword, Keyword, ListOfTypeAssignments),
 }
 
 #[derive(Debug, Node)]
-pub struct SpecparamDeclaration<'a> {
+pub struct SpecparamDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Option<PackedDimension<'a>>,
-        ListOfSpecparamAssignments<'a>,
-        Symbol<'a>,
+        Keyword,
+        Option<PackedDimension>,
+        ListOfSpecparamAssignments,
+        Symbol,
     ),
 }
 
diff --git a/src/parser/declarations/net_and_variable_types.rs b/src/parser/declarations/net_and_variable_types.rs
index 0f8e7fe..61a66ce 100644
--- a/src/parser/declarations/net_and_variable_types.rs
+++ b/src/parser/declarations/net_and_variable_types.rs
@@ -9,290 +9,278 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum CastingType<'a> {
-    SimpleType(Box<SimpleType<'a>>),
-    ConstantPrimary(Box<ConstantPrimary<'a>>),
-    Signing(Box<Signing<'a>>),
-    String(Keyword<'a>),
-    Const(Keyword<'a>),
+pub enum CastingType {
+    SimpleType(Box<SimpleType>),
+    ConstantPrimary(Box<ConstantPrimary>),
+    Signing(Box<Signing>),
+    String(Keyword),
+    Const(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum DataType<'a> {
-    Vector(DataTypeVector<'a>),
-    Atom(DataTypeAtom<'a>),
-    NonIntegerType(NonIntegerType<'a>),
-    StructUnion(Box<DataTypeStructUnion<'a>>),
-    Enum(DataTypeEnum<'a>),
-    String(Keyword<'a>),
-    Chandle(Keyword<'a>),
-    Virtual(DataTypeVirtual<'a>),
-    Type(DataTypeType<'a>),
-    ClassType(ClassType<'a>),
-    Event(Keyword<'a>),
-    PsCovergroupIdentifier(PsCovergroupIdentifier<'a>),
-    TypeReference(Box<TypeReference<'a>>),
+pub enum DataType {
+    Vector(DataTypeVector),
+    Atom(DataTypeAtom),
+    NonIntegerType(NonIntegerType),
+    StructUnion(Box<DataTypeStructUnion>),
+    Enum(DataTypeEnum),
+    String(Keyword),
+    Chandle(Keyword),
+    Virtual(DataTypeVirtual),
+    Type(DataTypeType),
+    ClassType(ClassType),
+    Event(Keyword),
+    PsCovergroupIdentifier(PsCovergroupIdentifier),
+    TypeReference(Box<TypeReference>),
 }
 
 #[derive(Debug, Node)]
-pub struct DataTypeVector<'a> {
+pub struct DataTypeVector {
+    pub nodes: (IntegerVectorType, Option<Signing>, Vec<PackedDimension>),
+}
+
+#[derive(Debug, Node)]
+pub struct DataTypeAtom {
+    pub nodes: (IntegerAtomType, Option<Signing>),
+}
+
+#[derive(Debug, Node)]
+pub struct DataTypeStructUnion {
     pub nodes: (
-        IntegerVectorType<'a>,
-        Option<Signing<'a>>,
-        Vec<PackedDimension<'a>>,
+        StructUnion,
+        Option<(Packed, Option<Signing>)>,
+        Brace<(StructUnionMember, Vec<StructUnionMember>)>,
+        Vec<PackedDimension>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DataTypeAtom<'a> {
-    pub nodes: (IntegerAtomType<'a>, Option<Signing<'a>>),
+pub struct Packed {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct DataTypeStructUnion<'a> {
+pub struct DataTypeEnum {
     pub nodes: (
-        StructUnion<'a>,
-        Option<(Packed<'a>, Option<Signing<'a>>)>,
-        Brace<'a, (StructUnionMember<'a>, Vec<StructUnionMember<'a>>)>,
-        Vec<PackedDimension<'a>>,
+        Keyword,
+        Option<EnumBaseType>,
+        Brace<List<Symbol, EnumNameDeclaration>>,
+        Vec<PackedDimension>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Packed<'a> {
-    pub nodes: (Keyword<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct DataTypeEnum<'a> {
+pub struct DataTypeVirtual {
     pub nodes: (
-        Keyword<'a>,
-        Option<EnumBaseType<'a>>,
-        Brace<'a, List<Symbol<'a>, EnumNameDeclaration<'a>>>,
-        Vec<PackedDimension<'a>>,
+        Keyword,
+        Option<Interface>,
+        InterfaceIdentifier,
+        Option<ParameterValueAssignment>,
+        Option<(Symbol, ModportIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DataTypeVirtual<'a> {
+pub struct Interface {
+    pub nodes: (Keyword,),
+}
+
+#[derive(Debug, Node)]
+pub struct DataTypeType {
     pub nodes: (
-        Keyword<'a>,
-        Option<Interface<'a>>,
-        InterfaceIdentifier<'a>,
-        Option<ParameterValueAssignment<'a>>,
-        Option<(Symbol<'a>, ModportIdentifier<'a>)>,
+        Option<PackageScopeOrClassScope>,
+        TypeIdentifier,
+        Vec<PackedDimension>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Interface<'a> {
-    pub nodes: (Keyword<'a>,),
+pub enum DataTypeOrImplicit {
+    DataType(DataType),
+    ImplicitDataType(ImplicitDataType),
 }
 
 #[derive(Debug, Node)]
-pub struct DataTypeType<'a> {
+pub struct ImplicitDataType {
+    pub nodes: (Option<Signing>, Vec<PackedDimension>),
+}
+
+#[derive(Debug, Node)]
+pub enum EnumBaseType {
+    Atom(EnumBaseTypeAtom),
+    Vector(EnumBaseTypeVector),
+    Type(EnumBaseTypeType),
+}
+
+#[derive(Debug, Node)]
+pub struct EnumBaseTypeAtom {
+    pub nodes: (IntegerAtomType, Option<Signing>),
+}
+
+#[derive(Debug, Node)]
+pub struct EnumBaseTypeVector {
+    pub nodes: (IntegerVectorType, Option<Signing>, Option<PackedDimension>),
+}
+
+#[derive(Debug, Node)]
+pub struct EnumBaseTypeType {
+    pub nodes: (TypeIdentifier, Option<PackedDimension>),
+}
+
+#[derive(Debug, Node)]
+pub struct EnumNameDeclaration {
     pub nodes: (
-        Option<PackageScopeOrClassScope<'a>>,
-        TypeIdentifier<'a>,
-        Vec<PackedDimension<'a>>,
+        EnumIdentifier,
+        Option<Bracket<(IntegralNumber, Option<(Symbol, IntegralNumber)>)>>,
+        Option<(Symbol, ConstantExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum DataTypeOrImplicit<'a> {
-    DataType(DataType<'a>),
-    ImplicitDataType(ImplicitDataType<'a>),
+pub struct ClassScope {
+    pub nodes: (ClassType, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ImplicitDataType<'a> {
-    pub nodes: (Option<Signing<'a>>, Vec<PackedDimension<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub enum EnumBaseType<'a> {
-    Atom(EnumBaseTypeAtom<'a>),
-    Vector(EnumBaseTypeVector<'a>),
-    Type(EnumBaseTypeType<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct EnumBaseTypeAtom<'a> {
-    pub nodes: (IntegerAtomType<'a>, Option<Signing<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct EnumBaseTypeVector<'a> {
+pub struct ClassType {
     pub nodes: (
-        IntegerVectorType<'a>,
-        Option<Signing<'a>>,
-        Option<PackedDimension<'a>>,
+        PsClassIdentifier,
+        Option<ParameterValueAssignment>,
+        Vec<(Symbol, ClassIdentifier, Option<ParameterValueAssignment>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct EnumBaseTypeType<'a> {
-    pub nodes: (TypeIdentifier<'a>, Option<PackedDimension<'a>>),
+pub enum IntegerType {
+    IntegerVectorType(IntegerVectorType),
+    IntegerAtomType(IntegerAtomType),
 }
 
 #[derive(Debug, Node)]
-pub struct EnumNameDeclaration<'a> {
+pub enum IntegerAtomType {
+    Byte(Keyword),
+    Shortint(Keyword),
+    Int(Keyword),
+    Longint(Keyword),
+    Integer(Keyword),
+    Time(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum IntegerVectorType {
+    Bit(Keyword),
+    Logic(Keyword),
+    Reg(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum NonIntegerType {
+    Shortreal(Keyword),
+    Real(Keyword),
+    Realtime(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum NetType {
+    Supply0(Keyword),
+    Supply1(Keyword),
+    Tri(Keyword),
+    Triand(Keyword),
+    Trior(Keyword),
+    Trireg(Keyword),
+    Tri0(Keyword),
+    Tri1(Keyword),
+    Uwire(Keyword),
+    Wire(Keyword),
+    Wand(Keyword),
+    Wor(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum NetPortType {
+    DataType(NetPortTypeDataType),
+    NetTypeIdentifier(NetTypeIdentifier),
+    Interconnect(NetPortTypeInterconnect),
+}
+
+#[derive(Debug, Node)]
+pub struct NetPortTypeDataType {
+    pub nodes: (Option<NetType>, DataTypeOrImplicit),
+}
+
+#[derive(Debug, Node)]
+pub struct NetPortTypeInterconnect {
+    pub nodes: (Keyword, ImplicitDataType),
+}
+
+#[derive(Debug, Node)]
+pub struct VariablePortType {
+    pub nodes: (VarDataType,),
+}
+
+#[derive(Debug, Node)]
+pub enum VarDataType {
+    DataType(DataType),
+    Var(VarDataTypeVar),
+}
+
+#[derive(Debug, Node)]
+pub struct VarDataTypeVar {
+    pub nodes: (Keyword, DataTypeOrImplicit),
+}
+
+#[derive(Debug, Node)]
+pub enum Signing {
+    Signed(Keyword),
+    Unsigned(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum SimpleType {
+    IntegerType(IntegerType),
+    NonIntegerType(NonIntegerType),
+    PsTypeIdentifier(PsTypeIdentifier),
+    PsParameterIdentifier(PsParameterIdentifier),
+}
+
+#[derive(Debug, Node)]
+pub struct StructUnionMember {
     pub nodes: (
-        EnumIdentifier<'a>,
-        Option<Bracket<'a, (IntegralNumber<'a>, Option<(Symbol<'a>, IntegralNumber<'a>)>)>>,
-        Option<(Symbol<'a>, ConstantExpression<'a>)>,
+        Vec<AttributeInstance>,
+        Option<RandomQualifier>,
+        DataTypeOrVoid,
+        ListOfVariableDeclAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassScope<'a> {
-    pub nodes: (ClassType<'a>, Symbol<'a>),
+pub enum DataTypeOrVoid {
+    DataType(DataType),
+    Void(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassType<'a> {
-    pub nodes: (
-        PsClassIdentifier<'a>,
-        Option<ParameterValueAssignment<'a>>,
-        Vec<(
-            Symbol<'a>,
-            ClassIdentifier<'a>,
-            Option<ParameterValueAssignment<'a>>,
-        )>,
-    ),
+pub enum StructUnion {
+    Struct(Keyword),
+    Union(Keyword),
+    UnionTagged((Keyword, Keyword)),
 }
 
 #[derive(Debug, Node)]
-pub enum IntegerType<'a> {
-    IntegerVectorType(IntegerVectorType<'a>),
-    IntegerAtomType(IntegerAtomType<'a>),
+pub enum TypeReference {
+    Expression(TypeReferenceExpression),
+    DataType(TypeReferenceDataType),
 }
 
 #[derive(Debug, Node)]
-pub enum IntegerAtomType<'a> {
-    Byte(Keyword<'a>),
-    Shortint(Keyword<'a>),
-    Int(Keyword<'a>),
-    Longint(Keyword<'a>),
-    Integer(Keyword<'a>),
-    Time(Keyword<'a>),
+pub struct TypeReferenceExpression {
+    pub nodes: (Keyword, Paren<Expression>),
 }
 
 #[derive(Debug, Node)]
-pub enum IntegerVectorType<'a> {
-    Bit(Keyword<'a>),
-    Logic(Keyword<'a>),
-    Reg(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum NonIntegerType<'a> {
-    Shortreal(Keyword<'a>),
-    Real(Keyword<'a>),
-    Realtime(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum NetType<'a> {
-    Supply0(Keyword<'a>),
-    Supply1(Keyword<'a>),
-    Tri(Keyword<'a>),
-    Triand(Keyword<'a>),
-    Trior(Keyword<'a>),
-    Trireg(Keyword<'a>),
-    Tri0(Keyword<'a>),
-    Tri1(Keyword<'a>),
-    Uwire(Keyword<'a>),
-    Wire(Keyword<'a>),
-    Wand(Keyword<'a>),
-    Wor(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum NetPortType<'a> {
-    DataType(NetPortTypeDataType<'a>),
-    NetTypeIdentifier(NetTypeIdentifier<'a>),
-    Interconnect(NetPortTypeInterconnect<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct NetPortTypeDataType<'a> {
-    pub nodes: (Option<NetType<'a>>, DataTypeOrImplicit<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct NetPortTypeInterconnect<'a> {
-    pub nodes: (Keyword<'a>, ImplicitDataType<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct VariablePortType<'a> {
-    pub nodes: (VarDataType<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub enum VarDataType<'a> {
-    DataType(DataType<'a>),
-    Var(VarDataTypeVar<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct VarDataTypeVar<'a> {
-    pub nodes: (Keyword<'a>, DataTypeOrImplicit<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum Signing<'a> {
-    Signed(Keyword<'a>),
-    Unsigned(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum SimpleType<'a> {
-    IntegerType(IntegerType<'a>),
-    NonIntegerType(NonIntegerType<'a>),
-    PsTypeIdentifier(PsTypeIdentifier<'a>),
-    PsParameterIdentifier(PsParameterIdentifier<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct StructUnionMember<'a> {
-    pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<RandomQualifier<'a>>,
-        DataTypeOrVoid<'a>,
-        ListOfVariableDeclAssignments<'a>,
-        Symbol<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub enum DataTypeOrVoid<'a> {
-    DataType(DataType<'a>),
-    Void(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum StructUnion<'a> {
-    Struct(Keyword<'a>),
-    Union(Keyword<'a>),
-    UnionTagged((Keyword<'a>, Keyword<'a>)),
-}
-
-#[derive(Debug, Node)]
-pub enum TypeReference<'a> {
-    Expression(TypeReferenceExpression<'a>),
-    DataType(TypeReferenceDataType<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct TypeReferenceExpression<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, Expression<'a>>),
-}
-
-#[derive(Debug, Node)]
-pub struct TypeReferenceDataType<'a> {
-    pub nodes: (Keyword<'a>, Paren<'a, DataType<'a>>),
+pub struct TypeReferenceDataType {
+    pub nodes: (Keyword, Paren<DataType>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/port_declarations.rs b/src/parser/declarations/port_declarations.rs
index 3a08425..a4066d1 100644
--- a/src/parser/declarations/port_declarations.rs
+++ b/src/parser/declarations/port_declarations.rs
@@ -8,77 +8,77 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct InoutDeclaration<'a> {
+pub struct InoutDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Option<NetPortType<'a>>,
-        ListOfPortIdentifiers<'a>,
+        Keyword,
+        Option<NetPortType>,
+        ListOfPortIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum InputDeclaration<'a> {
-    Net(InputDeclarationNet<'a>),
-    Variable(InputDeclarationVariable<'a>),
+pub enum InputDeclaration {
+    Net(InputDeclarationNet),
+    Variable(InputDeclarationVariable),
 }
 
 #[derive(Debug, Node)]
-pub struct InputDeclarationNet<'a> {
+pub struct InputDeclarationNet {
     pub nodes: (
-        Keyword<'a>,
-        Option<NetPortType<'a>>,
-        ListOfPortIdentifiers<'a>,
+        Keyword,
+        Option<NetPortType>,
+        ListOfPortIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InputDeclarationVariable<'a> {
+pub struct InputDeclarationVariable {
     pub nodes: (
-        Keyword<'a>,
-        VariablePortType<'a>,
-        ListOfVariableIdentifiers<'a>,
+        Keyword,
+        VariablePortType,
+        ListOfVariableIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum OutputDeclaration<'a> {
-    Net(OutputDeclarationNet<'a>),
-    Variable(OutputDeclarationVariable<'a>),
+pub enum OutputDeclaration {
+    Net(OutputDeclarationNet),
+    Variable(OutputDeclarationVariable),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputDeclarationNet<'a> {
+pub struct OutputDeclarationNet {
     pub nodes: (
-        Keyword<'a>,
-        Option<NetPortType<'a>>,
-        ListOfPortIdentifiers<'a>,
+        Keyword,
+        Option<NetPortType>,
+        ListOfPortIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputDeclarationVariable<'a> {
+pub struct OutputDeclarationVariable {
     pub nodes: (
-        Keyword<'a>,
-        VariablePortType<'a>,
-        ListOfVariableIdentifiers<'a>,
+        Keyword,
+        VariablePortType,
+        ListOfVariableIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfacePortDeclaration<'a> {
+pub struct InterfacePortDeclaration {
     pub nodes: (
-        InterfaceIdentifier<'a>,
-        Option<(Symbol<'a>, ModportIdentifier<'a>)>,
-        ListOfInterfaceIdentifiers<'a>,
+        InterfaceIdentifier,
+        Option<(Symbol, ModportIdentifier)>,
+        ListOfInterfaceIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RefDeclaration<'a> {
+pub struct RefDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        VariablePortType<'a>,
-        ListOfVariableIdentifiers<'a>,
+        Keyword,
+        VariablePortType,
+        ListOfVariableIdentifiers,
     ),
 }
 
diff --git a/src/parser/declarations/strengths.rs b/src/parser/declarations/strengths.rs
index 0239268..be38fe0 100644
--- a/src/parser/declarations/strengths.rs
+++ b/src/parser/declarations/strengths.rs
@@ -7,81 +7,81 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum DriveStrength<'a> {
-    Strength01(DriveStrength01<'a>),
-    Strength10(DriveStrength10<'a>),
-    Strength0z(DriveStrength0z<'a>),
-    Strength1z(DriveStrength1z<'a>),
-    Strengthz0(DriveStrengthz0<'a>),
-    Strengthz1(DriveStrengthz1<'a>),
+pub enum DriveStrength {
+    Strength01(DriveStrength01),
+    Strength10(DriveStrength10),
+    Strength0z(DriveStrength0z),
+    Strength1z(DriveStrength1z),
+    Strengthz0(DriveStrengthz0),
+    Strengthz1(DriveStrengthz1),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrength01<'a> {
-    pub nodes: (Paren<'a, (Strength0<'a>, Symbol<'a>, Strength1<'a>)>,),
+pub struct DriveStrength01 {
+    pub nodes: (Paren<(Strength0, Symbol, Strength1)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrength10<'a> {
-    pub nodes: (Paren<'a, (Strength1<'a>, Symbol<'a>, Strength0<'a>)>,),
+pub struct DriveStrength10 {
+    pub nodes: (Paren<(Strength1, Symbol, Strength0)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrength0z<'a> {
-    pub nodes: (Paren<'a, (Strength0<'a>, Symbol<'a>, Keyword<'a>)>,),
+pub struct DriveStrength0z {
+    pub nodes: (Paren<(Strength0, Symbol, Keyword)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrength1z<'a> {
-    pub nodes: (Paren<'a, (Strength1<'a>, Symbol<'a>, Keyword<'a>)>,),
+pub struct DriveStrength1z {
+    pub nodes: (Paren<(Strength1, Symbol, Keyword)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrengthz1<'a> {
-    pub nodes: (Paren<'a, (Keyword<'a>, Symbol<'a>, Strength1<'a>)>,),
+pub struct DriveStrengthz1 {
+    pub nodes: (Paren<(Keyword, Symbol, Strength1)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DriveStrengthz0<'a> {
-    pub nodes: (Paren<'a, (Keyword<'a>, Symbol<'a>, Strength0<'a>)>,),
+pub struct DriveStrengthz0 {
+    pub nodes: (Paren<(Keyword, Symbol, Strength0)>,),
 }
 
 #[derive(Debug, Node)]
-pub enum Strength0<'a> {
-    Supply0(Keyword<'a>),
-    Strong0(Keyword<'a>),
-    Pull0(Keyword<'a>),
-    Weak0(Keyword<'a>),
+pub enum Strength0 {
+    Supply0(Keyword),
+    Strong0(Keyword),
+    Pull0(Keyword),
+    Weak0(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum Strength1<'a> {
-    Supply1(Keyword<'a>),
-    Strong1(Keyword<'a>),
-    Pull1(Keyword<'a>),
-    Weak1(Keyword<'a>),
+pub enum Strength1 {
+    Supply1(Keyword),
+    Strong1(Keyword),
+    Pull1(Keyword),
+    Weak1(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum ChargeStrength<'a> {
-    Small(ChargeStrengthSmall<'a>),
-    Medium(ChargeStrengthMedium<'a>),
-    Large(ChargeStrengthLarge<'a>),
+pub enum ChargeStrength {
+    Small(ChargeStrengthSmall),
+    Medium(ChargeStrengthMedium),
+    Large(ChargeStrengthLarge),
 }
 
 #[derive(Debug, Node)]
-pub struct ChargeStrengthSmall<'a> {
-    pub nodes: (Paren<'a, Keyword<'a>>,),
+pub struct ChargeStrengthSmall {
+    pub nodes: (Paren<Keyword>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ChargeStrengthMedium<'a> {
-    pub nodes: (Paren<'a, Keyword<'a>>,),
+pub struct ChargeStrengthMedium {
+    pub nodes: (Paren<Keyword>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ChargeStrengthLarge<'a> {
-    pub nodes: (Paren<'a, Keyword<'a>>,),
+pub struct ChargeStrengthLarge {
+    pub nodes: (Paren<Keyword>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/task_declarations.rs b/src/parser/declarations/task_declarations.rs
index bdace00..0ee7c7a 100644
--- a/src/parser/declarations/task_declarations.rs
+++ b/src/parser/declarations/task_declarations.rs
@@ -9,94 +9,90 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct TaskDeclaration<'a> {
-    pub nodes: (Keyword<'a>, Option<Lifetime<'a>>, TaskBodyDeclaration<'a>),
+pub struct TaskDeclaration {
+    pub nodes: (Keyword, Option<Lifetime>, TaskBodyDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum TaskBodyDeclaration<'a> {
-    WithoutPort(TaskBodyDeclarationWithoutPort<'a>),
-    WithPort(TaskBodyDeclarationWithPort<'a>),
+pub enum TaskBodyDeclaration {
+    WithoutPort(TaskBodyDeclarationWithoutPort),
+    WithPort(TaskBodyDeclarationWithPort),
 }
 
 #[derive(Debug, Node)]
-pub struct TaskBodyDeclarationWithoutPort<'a> {
+pub struct TaskBodyDeclarationWithoutPort {
     pub nodes: (
-        Option<InterfaceIdentifierOrClassScope<'a>>,
-        TaskIdentifier<'a>,
-        Symbol<'a>,
-        Vec<TfItemDeclaration<'a>>,
-        Vec<StatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, TaskIdentifier<'a>)>,
+        Option<InterfaceIdentifierOrClassScope>,
+        TaskIdentifier,
+        Symbol,
+        Vec<TfItemDeclaration>,
+        Vec<StatementOrNull>,
+        Keyword,
+        Option<(Symbol, TaskIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TaskBodyDeclarationWithPort<'a> {
+pub struct TaskBodyDeclarationWithPort {
     pub nodes: (
-        Option<InterfaceIdentifierOrClassScope<'a>>,
-        TaskIdentifier<'a>,
-        Paren<'a, Option<TfPortList<'a>>>,
-        Symbol<'a>,
-        Vec<BlockItemDeclaration<'a>>,
-        Vec<StatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, TaskIdentifier<'a>)>,
+        Option<InterfaceIdentifierOrClassScope>,
+        TaskIdentifier,
+        Paren<Option<TfPortList>>,
+        Symbol,
+        Vec<BlockItemDeclaration>,
+        Vec<StatementOrNull>,
+        Keyword,
+        Option<(Symbol, TaskIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TfItemDeclaration<'a> {
-    BlockItemDeclaration(BlockItemDeclaration<'a>),
-    TfPortDeclaration(TfPortDeclaration<'a>),
+pub enum TfItemDeclaration {
+    BlockItemDeclaration(BlockItemDeclaration),
+    TfPortDeclaration(TfPortDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct TfPortList<'a> {
-    pub nodes: (List<Symbol<'a>, TfPortItem<'a>>,),
+pub struct TfPortList {
+    pub nodes: (List<Symbol, TfPortItem>,),
 }
 
 #[derive(Debug, Node)]
-pub struct TfPortItem<'a> {
+pub struct TfPortItem {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<TfPortDirection<'a>>,
-        Option<Var<'a>>,
-        Option<DataTypeOrImplicit<'a>>,
+        Vec<AttributeInstance>,
+        Option<TfPortDirection>,
+        Option<Var>,
+        Option<DataTypeOrImplicit>,
         Option<(
-            PortIdentifier<'a>,
-            Vec<VariableDimension<'a>>,
-            Option<(Symbol<'a>, Expression<'a>)>,
+            PortIdentifier,
+            Vec<VariableDimension>,
+            Option<(Symbol, Expression)>,
         )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TfPortDirection<'a> {
-    PortDirection(PortDirection<'a>),
-    ConstRef((Keyword<'a>, Keyword<'a>)),
+pub enum TfPortDirection {
+    PortDirection(PortDirection),
+    ConstRef((Keyword, Keyword)),
 }
 
 #[derive(Debug, Node)]
-pub struct TfPortDeclaration<'a> {
+pub struct TfPortDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        TfPortDirection<'a>,
-        Option<Var<'a>>,
-        Option<DataTypeOrImplicit<'a>>,
-        ListOfTfVariableIdentifiers<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        TfPortDirection,
+        Option<Var>,
+        Option<DataTypeOrImplicit>,
+        ListOfTfVariableIdentifiers,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TaskPrototype<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        TaskIdentifier<'a>,
-        Option<Paren<'a, Option<TfPortList<'a>>>>,
-    ),
+pub struct TaskPrototype {
+    pub nodes: (Keyword, TaskIdentifier, Option<Paren<Option<TfPortList>>>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/declarations/type_declarations.rs b/src/parser/declarations/type_declarations.rs
index 7205831..6514140 100644
--- a/src/parser/declarations/type_declarations.rs
+++ b/src/parser/declarations/type_declarations.rs
@@ -9,221 +9,221 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum DataDeclaration<'a> {
-    Variable(DataDeclarationVariable<'a>),
-    TypeDeclaration(TypeDeclaration<'a>),
-    PackageImportDeclaration(PackageImportDeclaration<'a>),
-    NetTypeDeclaration(NetTypeDeclaration<'a>),
+pub enum DataDeclaration {
+    Variable(DataDeclarationVariable),
+    TypeDeclaration(TypeDeclaration),
+    PackageImportDeclaration(PackageImportDeclaration),
+    NetTypeDeclaration(NetTypeDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct DataDeclarationVariable<'a> {
+pub struct DataDeclarationVariable {
     pub nodes: (
-        Option<Const<'a>>,
-        Option<Var<'a>>,
-        Option<Lifetime<'a>>,
-        Option<DataTypeOrImplicit<'a>>,
-        ListOfVariableDeclAssignments<'a>,
-        Symbol<'a>,
+        Option<Const>,
+        Option<Var>,
+        Option<Lifetime>,
+        Option<DataTypeOrImplicit>,
+        ListOfVariableDeclAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Const<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Const {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageImportDeclaration<'a> {
+pub struct PackageImportDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        List<Symbol<'a>, PackageImportItem<'a>>,
-        Symbol<'a>,
+        Keyword,
+        List<Symbol, PackageImportItem>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PackageImportItem<'a> {
-    Identifier(PackageImportItemIdentifier<'a>),
-    Asterisk(PackageImportItemAsterisk<'a>),
+pub enum PackageImportItem {
+    Identifier(PackageImportItemIdentifier),
+    Asterisk(PackageImportItemAsterisk),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageImportItemIdentifier<'a> {
-    pub nodes: (PackageIdentifier<'a>, Symbol<'a>, Identifier<'a>),
+pub struct PackageImportItemIdentifier {
+    pub nodes: (PackageIdentifier, Symbol, Identifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageImportItemAsterisk<'a> {
-    pub nodes: (PackageIdentifier<'a>, Symbol<'a>, Symbol<'a>),
+pub struct PackageImportItemAsterisk {
+    pub nodes: (PackageIdentifier, Symbol, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum PackageExportDeclaration<'a> {
-    Asterisk(PackageExportDeclarationAsterisk<'a>),
-    Item(PackageExportDeclarationItem<'a>),
+pub enum PackageExportDeclaration {
+    Asterisk(PackageExportDeclarationAsterisk),
+    Item(PackageExportDeclarationItem),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageExportDeclarationAsterisk<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>, Symbol<'a>),
+pub struct PackageExportDeclarationAsterisk {
+    pub nodes: (Keyword, Symbol, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageExportDeclarationItem<'a> {
+pub struct PackageExportDeclarationItem {
     pub nodes: (
-        Keyword<'a>,
-        List<Symbol<'a>, PackageImportItem<'a>>,
-        Symbol<'a>,
+        Keyword,
+        List<Symbol, PackageImportItem>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarDeclaration<'a> {
-    pub nodes: (Keyword<'a>, ListOfGenvarIdentifiers<'a>, Symbol<'a>),
+pub struct GenvarDeclaration {
+    pub nodes: (Keyword, ListOfGenvarIdentifiers, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum NetDeclaration<'a> {
-    NetType(NetDeclarationNetType<'a>),
-    NetTypeIdentifier(NetDeclarationNetTypeIdentifier<'a>),
-    Interconnect(NetDeclarationInterconnect<'a>),
+pub enum NetDeclaration {
+    NetType(NetDeclarationNetType),
+    NetTypeIdentifier(NetDeclarationNetTypeIdentifier),
+    Interconnect(NetDeclarationInterconnect),
 }
 
 #[derive(Debug, Node)]
-pub struct NetDeclarationNetType<'a> {
+pub struct NetDeclarationNetType {
     pub nodes: (
-        NetType<'a>,
-        Option<Strength<'a>>,
-        Option<VectorScalar<'a>>,
-        Option<DataTypeOrImplicit<'a>>,
-        Option<Delay3<'a>>,
-        ListOfNetDeclAssignments<'a>,
-        Symbol<'a>,
+        NetType,
+        Option<Strength>,
+        Option<VectorScalar>,
+        Option<DataTypeOrImplicit>,
+        Option<Delay3>,
+        ListOfNetDeclAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum Strength<'a> {
-    Drive(DriveStrength<'a>),
-    Charge(ChargeStrength<'a>),
+pub enum Strength {
+    Drive(DriveStrength),
+    Charge(ChargeStrength),
 }
 
 #[derive(Debug, Node)]
-pub enum VectorScalar<'a> {
-    Vectored(Keyword<'a>),
-    Scalared(Keyword<'a>),
+pub enum VectorScalar {
+    Vectored(Keyword),
+    Scalared(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct NetDeclarationNetTypeIdentifier<'a> {
+pub struct NetDeclarationNetTypeIdentifier {
     pub nodes: (
-        NetTypeIdentifier<'a>,
-        Option<DelayControl<'a>>,
-        ListOfNetDeclAssignments<'a>,
-        Symbol<'a>,
+        NetTypeIdentifier,
+        Option<DelayControl>,
+        ListOfNetDeclAssignments,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NetDeclarationInterconnect<'a> {
+pub struct NetDeclarationInterconnect {
     pub nodes: (
-        Keyword<'a>,
-        ImplicitDataType<'a>,
-        Option<(Symbol<'a>, DelayValue<'a>)>,
-        NetIdentifier<'a>,
-        Vec<UnpackedDimension<'a>>,
-        Option<(Symbol<'a>, NetIdentifier<'a>, Vec<UnpackedDimension<'a>>)>,
-        Symbol<'a>,
+        Keyword,
+        ImplicitDataType,
+        Option<(Symbol, DelayValue)>,
+        NetIdentifier,
+        Vec<UnpackedDimension>,
+        Option<(Symbol, NetIdentifier, Vec<UnpackedDimension>)>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TypeDeclaration<'a> {
-    DataType(TypeDeclarationDataType<'a>),
-    Interface(TypeDeclarationInterface<'a>),
-    Reserved(TypeDeclarationReserved<'a>),
+pub enum TypeDeclaration {
+    DataType(TypeDeclarationDataType),
+    Interface(TypeDeclarationInterface),
+    Reserved(TypeDeclarationReserved),
 }
 
 #[derive(Debug, Node)]
-pub struct TypeDeclarationDataType<'a> {
+pub struct TypeDeclarationDataType {
     pub nodes: (
-        Keyword<'a>,
-        DataType<'a>,
-        TypeIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Symbol<'a>,
+        Keyword,
+        DataType,
+        TypeIdentifier,
+        Vec<VariableDimension>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TypeDeclarationInterface<'a> {
+pub struct TypeDeclarationInterface {
     pub nodes: (
-        Keyword<'a>,
-        InterfaceInstanceIdentifier<'a>,
-        ConstantBitSelect<'a>,
-        Symbol<'a>,
-        TypeIdentifier<'a>,
-        TypeIdentifier<'a>,
-        Symbol<'a>,
+        Keyword,
+        InterfaceInstanceIdentifier,
+        ConstantBitSelect,
+        Symbol,
+        TypeIdentifier,
+        TypeIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TypeDeclarationReserved<'a> {
+pub struct TypeDeclarationReserved {
     pub nodes: (
-        Keyword<'a>,
-        Option<TypeDeclarationKeyword<'a>>,
-        TypeIdentifier<'a>,
-        Symbol<'a>,
+        Keyword,
+        Option<TypeDeclarationKeyword>,
+        TypeIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TypeDeclarationKeyword<'a> {
-    Enum(Keyword<'a>),
-    Struct(Keyword<'a>),
-    Union(Keyword<'a>),
-    Class(Keyword<'a>),
-    InterfaceClass((Keyword<'a>, Keyword<'a>)),
+pub enum TypeDeclarationKeyword {
+    Enum(Keyword),
+    Struct(Keyword),
+    Union(Keyword),
+    Class(Keyword),
+    InterfaceClass((Keyword, Keyword)),
 }
 
 #[derive(Debug, Node)]
-pub enum NetTypeDeclaration<'a> {
-    DataType(NetTypeDeclarationDataType<'a>),
-    NetType(NetTypeDeclarationNetType<'a>),
+pub enum NetTypeDeclaration {
+    DataType(NetTypeDeclarationDataType),
+    NetType(NetTypeDeclarationNetType),
 }
 
 #[derive(Debug, Node)]
-pub struct NetTypeDeclarationDataType<'a> {
+pub struct NetTypeDeclarationDataType {
     pub nodes: (
-        Keyword<'a>,
-        DataType<'a>,
-        NetTypeIdentifier<'a>,
+        Keyword,
+        DataType,
+        NetTypeIdentifier,
         Option<(
-            Keyword<'a>,
-            Option<PackageScopeOrClassScope<'a>>,
-            TfIdentifier<'a>,
+            Keyword,
+            Option<PackageScopeOrClassScope>,
+            TfIdentifier,
         )>,
-        Symbol<'a>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NetTypeDeclarationNetType<'a> {
+pub struct NetTypeDeclarationNetType {
     pub nodes: (
-        Keyword<'a>,
-        Option<PackageScopeOrClassScope<'a>>,
-        NetTypeIdentifier<'a>,
-        NetTypeIdentifier<'a>,
-        Symbol<'a>,
+        Keyword,
+        Option<PackageScopeOrClassScope>,
+        NetTypeIdentifier,
+        NetTypeIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum Lifetime<'a> {
-    Static(Keyword<'a>),
-    Automatic(Keyword<'a>),
+pub enum Lifetime {
+    Static(Keyword),
+    Automatic(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/concatenations.rs b/src/parser/expressions/concatenations.rs
index 0ebdd15..4852894 100644
--- a/src/parser/expressions/concatenations.rs
+++ b/src/parser/expressions/concatenations.rs
@@ -8,99 +8,99 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct Concatenation<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, Expression<'a>>>,),
+pub struct Concatenation {
+    pub nodes: (Brace< List<Symbol, Expression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantConcatenation<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, ConstantExpression<'a>>>,),
+pub struct ConstantConcatenation {
+    pub nodes: (Brace< List<Symbol, ConstantExpression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantMultipleConcatenation<'a> {
-    pub nodes: (Brace<'a, (ConstantExpression<'a>, ConstantConcatenation<'a>)>,),
+pub struct ConstantMultipleConcatenation {
+    pub nodes: (Brace< (ConstantExpression, ConstantConcatenation)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathConcatenation<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, ModulePathExpression<'a>>>,),
+pub struct ModulePathConcatenation {
+    pub nodes: (Brace< List<Symbol, ModulePathExpression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathMultipleConcatenation<'a> {
-    pub nodes: (Brace<'a, (ConstantExpression<'a>, ModulePathConcatenation<'a>)>,),
+pub struct ModulePathMultipleConcatenation {
+    pub nodes: (Brace< (ConstantExpression, ModulePathConcatenation)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct MultipleConcatenation<'a> {
-    pub nodes: (Brace<'a, (Expression<'a>, Concatenation<'a>)>,),
+pub struct MultipleConcatenation {
+    pub nodes: (Brace< (Expression, Concatenation)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct StreamingConcatenation<'a> {
+pub struct StreamingConcatenation {
     pub nodes: (
         Brace<
-            'a,
+            
             (
-                StreamOperator<'a>,
-                Option<SliceSize<'a>>,
-                StreamConcatenation<'a>,
+                StreamOperator,
+                Option<SliceSize>,
+                StreamConcatenation,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct StreamOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct StreamOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub enum SliceSize<'a> {
-    SimpleType(SimpleType<'a>),
-    ConstantExpression(ConstantExpression<'a>),
+pub enum SliceSize {
+    SimpleType(SimpleType),
+    ConstantExpression(ConstantExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct StreamConcatenation<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, StreamExpression<'a>>>,),
+pub struct StreamConcatenation {
+    pub nodes: (Brace< List<Symbol, StreamExpression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct StreamExpression<'a> {
+pub struct StreamExpression {
     pub nodes: (
-        Expression<'a>,
-        Option<(Keyword<'a>, Bracket<'a, ArrayRangeExpression<'a>>)>,
+        Expression,
+        Option<(Keyword, Bracket< ArrayRangeExpression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ArrayRangeExpression<'a> {
-    Expression(Expression<'a>),
-    Colon(ArrayRangeExpressionColon<'a>),
-    PlusColon(ArrayRangeExpressionPlusColon<'a>),
-    MinusColon(ArrayRangeExpressionMinusColon<'a>),
+pub enum ArrayRangeExpression {
+    Expression(Expression),
+    Colon(ArrayRangeExpressionColon),
+    PlusColon(ArrayRangeExpressionPlusColon),
+    MinusColon(ArrayRangeExpressionMinusColon),
 }
 
 #[derive(Debug, Node)]
-pub struct ArrayRangeExpressionColon<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, Expression<'a>),
+pub struct ArrayRangeExpressionColon {
+    pub nodes: (Expression, Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct ArrayRangeExpressionPlusColon<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, Expression<'a>),
+pub struct ArrayRangeExpressionPlusColon {
+    pub nodes: (Expression, Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct ArrayRangeExpressionMinusColon<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, Expression<'a>),
+pub struct ArrayRangeExpressionMinusColon {
+    pub nodes: (Expression, Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct EmptyUnpackedArrayConcatenation<'a> {
-    pub nodes: (Symbol<'a>, Symbol<'a>),
+pub struct EmptyUnpackedArrayConcatenation {
+    pub nodes: (Symbol, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/expression_leftside_values.rs b/src/parser/expressions/expression_leftside_values.rs
index 9d86e0a..64b0690 100644
--- a/src/parser/expressions/expression_leftside_values.rs
+++ b/src/parser/expressions/expression_leftside_values.rs
@@ -7,66 +7,66 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum NetLvalue<'a> {
-    Identifier(NetLvalueIdentifier<'a>),
-    Lvalue(Box<NetLvalueLvalue<'a>>),
-    Pattern(Box<NetLvaluePattern<'a>>),
+pub enum NetLvalue {
+    Identifier(NetLvalueIdentifier),
+    Lvalue(Box<NetLvalueLvalue>),
+    Pattern(Box<NetLvaluePattern>),
 }
 
 #[derive(Debug, Node)]
-pub struct NetLvalueIdentifier<'a> {
-    pub nodes: (PsOrHierarchicalNetIdentifier<'a>, ConstantSelect<'a>),
+pub struct NetLvalueIdentifier {
+    pub nodes: (PsOrHierarchicalNetIdentifier, ConstantSelect),
 }
 
 #[derive(Debug, Node)]
-pub struct NetLvalueLvalue<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, NetLvalue<'a>>>,),
+pub struct NetLvalueLvalue {
+    pub nodes: (Brace<List<Symbol, NetLvalue>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct NetLvaluePattern<'a> {
+pub struct NetLvaluePattern {
     pub nodes: (
-        Option<AssignmentPatternExpressionType<'a>>,
-        AssignmentPatternNetLvalue<'a>,
+        Option<AssignmentPatternExpressionType>,
+        AssignmentPatternNetLvalue,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum VariableLvalue<'a> {
-    Identifier(VariableLvalueIdentifier<'a>),
-    Lvalue(Box<VariableLvalueLvalue<'a>>),
-    Pattern(Box<VariableLvaluePattern<'a>>),
-    StreamingConcatenation(StreamingConcatenation<'a>),
+pub enum VariableLvalue {
+    Identifier(VariableLvalueIdentifier),
+    Lvalue(Box<VariableLvalueLvalue>),
+    Pattern(Box<VariableLvaluePattern>),
+    StreamingConcatenation(StreamingConcatenation),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableLvalueIdentifier<'a> {
+pub struct VariableLvalueIdentifier {
     pub nodes: (
-        Option<ImplicitClassHandleOrPackageScope<'a>>,
-        HierarchicalVariableIdentifier<'a>,
-        Select<'a>,
+        Option<ImplicitClassHandleOrPackageScope>,
+        HierarchicalVariableIdentifier,
+        Select,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableLvalueLvalue<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, VariableLvalue<'a>>>,),
+pub struct VariableLvalueLvalue {
+    pub nodes: (Brace<List<Symbol, VariableLvalue>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableLvaluePattern<'a> {
+pub struct VariableLvaluePattern {
     pub nodes: (
-        Option<AssignmentPatternExpressionType<'a>>,
-        AssignmentPatternVariableLvalue<'a>,
+        Option<AssignmentPatternExpressionType>,
+        AssignmentPatternVariableLvalue,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NonrangeVariableLvalue<'a> {
+pub struct NonrangeVariableLvalue {
     pub nodes: (
-        Option<ImplicitClassHandleOrPackageScope<'a>>,
-        HierarchicalVariableIdentifier<'a>,
-        NonrangeSelect<'a>,
+        Option<ImplicitClassHandleOrPackageScope>,
+        HierarchicalVariableIdentifier,
+        NonrangeSelect,
     ),
 }
 
diff --git a/src/parser/expressions/expressions.rs b/src/parser/expressions/expressions.rs
index 573e6ea..bfcb237 100644
--- a/src/parser/expressions/expressions.rs
+++ b/src/parser/expressions/expressions.rs
@@ -8,273 +8,273 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum IncOrDecExpression<'a> {
-    Prefix(IncOrDecExpressionPrefix<'a>),
-    Suffix(IncOrDecExpressionSuffix<'a>),
+pub enum IncOrDecExpression {
+    Prefix(IncOrDecExpressionPrefix),
+    Suffix(IncOrDecExpressionSuffix),
 }
 
 #[derive(Debug, Node)]
-pub struct IncOrDecExpressionPrefix<'a> {
+pub struct IncOrDecExpressionPrefix {
     pub nodes: (
-        IncOrDecOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        VariableLvalue<'a>,
+        IncOrDecOperator,
+        Vec<AttributeInstance>,
+        VariableLvalue,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct IncOrDecExpressionSuffix<'a> {
+pub struct IncOrDecExpressionSuffix {
     pub nodes: (
-        VariableLvalue<'a>,
-        Vec<AttributeInstance<'a>>,
-        IncOrDecOperator<'a>,
+        VariableLvalue,
+        Vec<AttributeInstance>,
+        IncOrDecOperator,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConditionalExpression<'a> {
+pub struct ConditionalExpression {
     pub nodes: (
-        CondPredicate<'a>,
-        Symbol<'a>,
-        Vec<AttributeInstance<'a>>,
-        Expression<'a>,
-        Symbol<'a>,
-        Expression<'a>,
+        CondPredicate,
+        Symbol,
+        Vec<AttributeInstance>,
+        Expression,
+        Symbol,
+        Expression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstantExpression<'a> {
-    ConstantPrimary(Box<ConstantPrimary<'a>>),
-    Unary(Box<ConstantExpressionUnary<'a>>),
-    Binary(Box<ConstantExpressionBinary<'a>>),
-    Ternary(Box<ConstantExpressionTernary<'a>>),
+pub enum ConstantExpression {
+    ConstantPrimary(Box<ConstantPrimary>),
+    Unary(Box<ConstantExpressionUnary>),
+    Binary(Box<ConstantExpressionBinary>),
+    Ternary(Box<ConstantExpressionTernary>),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantExpressionUnary<'a> {
+pub struct ConstantExpressionUnary {
     pub nodes: (
-        UnaryOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        ConstantPrimary<'a>,
+        UnaryOperator,
+        Vec<AttributeInstance>,
+        ConstantPrimary,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantExpressionBinary<'a> {
+pub struct ConstantExpressionBinary {
     pub nodes: (
-        ConstantExpression<'a>,
-        BinaryOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        ConstantExpression<'a>,
+        ConstantExpression,
+        BinaryOperator,
+        Vec<AttributeInstance>,
+        ConstantExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantExpressionTernary<'a> {
+pub struct ConstantExpressionTernary {
     pub nodes: (
-        ConstantExpression<'a>,
-        Symbol<'a>,
-        Vec<AttributeInstance<'a>>,
-        ConstantExpression<'a>,
-        Symbol<'a>,
-        ConstantExpression<'a>,
+        ConstantExpression,
+        Symbol,
+        Vec<AttributeInstance>,
+        ConstantExpression,
+        Symbol,
+        ConstantExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstantMintypmaxExpression<'a> {
-    Unary(ConstantExpression<'a>),
-    Ternary(ConstantMintypmaxExpressionTernary<'a>),
+pub enum ConstantMintypmaxExpression {
+    Unary(ConstantExpression),
+    Ternary(ConstantMintypmaxExpressionTernary),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantMintypmaxExpressionTernary<'a> {
+pub struct ConstantMintypmaxExpressionTernary {
     pub nodes: (
-        ConstantExpression<'a>,
-        Symbol<'a>,
-        ConstantExpression<'a>,
-        Symbol<'a>,
-        ConstantExpression<'a>,
+        ConstantExpression,
+        Symbol,
+        ConstantExpression,
+        Symbol,
+        ConstantExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstantParamExpression<'a> {
-    ConstantMintypmaxExpression(ConstantMintypmaxExpression<'a>),
-    DataType(DataType<'a>),
-    Dollar(Symbol<'a>),
+pub enum ConstantParamExpression {
+    ConstantMintypmaxExpression(ConstantMintypmaxExpression),
+    DataType(DataType),
+    Dollar(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum ParamExpression<'a> {
-    MintypmaxExpression(MintypmaxExpression<'a>),
-    DataType(Box<DataType<'a>>),
-    Dollar(Symbol<'a>),
+pub enum ParamExpression {
+    MintypmaxExpression(MintypmaxExpression),
+    DataType(Box<DataType>),
+    Dollar(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstantRangeExpression<'a> {
-    ConstantExpression(ConstantExpression<'a>),
-    ConstantPartSelectRange(ConstantPartSelectRange<'a>),
+pub enum ConstantRangeExpression {
+    ConstantExpression(ConstantExpression),
+    ConstantPartSelectRange(ConstantPartSelectRange),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstantPartSelectRange<'a> {
-    ConstantRange(ConstantRange<'a>),
-    ConstantIndexedRange(ConstantIndexedRange<'a>),
+pub enum ConstantPartSelectRange {
+    ConstantRange(ConstantRange),
+    ConstantIndexedRange(ConstantIndexedRange),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantRange<'a> {
-    pub nodes: (ConstantExpression<'a>, Symbol<'a>, ConstantExpression<'a>),
+pub struct ConstantRange {
+    pub nodes: (ConstantExpression, Symbol, ConstantExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantIndexedRange<'a> {
-    pub nodes: (ConstantExpression<'a>, Symbol<'a>, ConstantExpression<'a>),
+pub struct ConstantIndexedRange {
+    pub nodes: (ConstantExpression, Symbol, ConstantExpression),
 }
 
 #[derive(Debug, Node)]
-pub enum Expression<'a> {
-    Primary(Box<Primary<'a>>),
-    Unary(Box<ExpressionUnary<'a>>),
-    IncOrDecExpression(Box<IncOrDecExpression<'a>>),
-    OperatorAssignment(Box<ExpressionOperatorAssignment<'a>>),
-    Binary(Box<ExpressionBinary<'a>>),
-    ConditionalExpression(Box<ConditionalExpression<'a>>),
-    InsideExpression(Box<InsideExpression<'a>>),
-    TaggedUnionExpression(Box<TaggedUnionExpression<'a>>),
+pub enum Expression {
+    Primary(Box<Primary>),
+    Unary(Box<ExpressionUnary>),
+    IncOrDecExpression(Box<IncOrDecExpression>),
+    OperatorAssignment(Box<ExpressionOperatorAssignment>),
+    Binary(Box<ExpressionBinary>),
+    ConditionalExpression(Box<ConditionalExpression>),
+    InsideExpression(Box<InsideExpression>),
+    TaggedUnionExpression(Box<TaggedUnionExpression>),
 }
 
 #[derive(Debug, Node)]
-pub struct ExpressionUnary<'a> {
-    pub nodes: (UnaryOperator<'a>, Vec<AttributeInstance<'a>>, Primary<'a>),
+pub struct ExpressionUnary {
+    pub nodes: (UnaryOperator, Vec<AttributeInstance>, Primary),
 }
 
 #[derive(Debug, Node)]
-pub struct ExpressionOperatorAssignment<'a> {
-    pub nodes: (Paren<'a, OperatorAssignment<'a>>,),
+pub struct ExpressionOperatorAssignment {
+    pub nodes: (Paren< OperatorAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ExpressionBinary<'a> {
+pub struct ExpressionBinary {
     pub nodes: (
-        Expression<'a>,
-        BinaryOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        Expression<'a>,
+        Expression,
+        BinaryOperator,
+        Vec<AttributeInstance>,
+        Expression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TaggedUnionExpression<'a> {
-    pub nodes: (Keyword<'a>, MemberIdentifier<'a>, Option<Expression<'a>>),
+pub struct TaggedUnionExpression {
+    pub nodes: (Keyword, MemberIdentifier, Option<Expression>),
 }
 
 #[derive(Debug, Node)]
-pub struct InsideExpression<'a> {
-    pub nodes: (Expression<'a>, Keyword<'a>, Brace<'a, OpenRangeList<'a>>),
+pub struct InsideExpression {
+    pub nodes: (Expression, Keyword, Brace< OpenRangeList>),
 }
 
 #[derive(Debug, Node)]
-pub enum ValueRange<'a> {
-    Expression(Expression<'a>),
-    Binary(ValueRangeBinary<'a>),
+pub enum ValueRange {
+    Expression(Expression),
+    Binary(ValueRangeBinary),
 }
 
 #[derive(Debug, Node)]
-pub struct ValueRangeBinary<'a> {
-    pub nodes: (Bracket<'a, (Expression<'a>, Symbol<'a>, Expression<'a>)>,),
+pub struct ValueRangeBinary {
+    pub nodes: (Bracket< (Expression, Symbol, Expression)>,),
 }
 
 #[derive(Debug, Node)]
-pub enum MintypmaxExpression<'a> {
-    Expression(Expression<'a>),
-    Ternary(MintypmaxExpressionTernary<'a>),
+pub enum MintypmaxExpression {
+    Expression(Expression),
+    Ternary(MintypmaxExpressionTernary),
 }
 
 #[derive(Debug, Node)]
-pub struct MintypmaxExpressionTernary<'a> {
+pub struct MintypmaxExpressionTernary {
     pub nodes: (
-        Expression<'a>,
-        Symbol<'a>,
-        Expression<'a>,
-        Symbol<'a>,
-        Expression<'a>,
+        Expression,
+        Symbol,
+        Expression,
+        Symbol,
+        Expression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathConditionalExpression<'a> {
+pub struct ModulePathConditionalExpression {
     pub nodes: (
-        ModulePathExpression<'a>,
-        Symbol<'a>,
-        Vec<AttributeInstance<'a>>,
-        ModulePathExpression<'a>,
-        Symbol<'a>,
-        ModulePathExpression<'a>,
+        ModulePathExpression,
+        Symbol,
+        Vec<AttributeInstance>,
+        ModulePathExpression,
+        Symbol,
+        ModulePathExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ModulePathExpression<'a> {
-    ModulePathPrimary(Box<ModulePathPrimary<'a>>),
-    Unary(Box<ModulePathExpressionUnary<'a>>),
-    Binary(Box<ModulePathExpressionBinary<'a>>),
-    ModulePathConditionalExpression(Box<ModulePathConditionalExpression<'a>>),
+pub enum ModulePathExpression {
+    ModulePathPrimary(Box<ModulePathPrimary>),
+    Unary(Box<ModulePathExpressionUnary>),
+    Binary(Box<ModulePathExpressionBinary>),
+    ModulePathConditionalExpression(Box<ModulePathConditionalExpression>),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathExpressionUnary<'a> {
+pub struct ModulePathExpressionUnary {
     pub nodes: (
-        UnaryModulePathOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        ModulePathPrimary<'a>,
+        UnaryModulePathOperator,
+        Vec<AttributeInstance>,
+        ModulePathPrimary,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathExpressionBinary<'a> {
+pub struct ModulePathExpressionBinary {
     pub nodes: (
-        ModulePathExpression<'a>,
-        BinaryModulePathOperator<'a>,
-        Vec<AttributeInstance<'a>>,
-        ModulePathExpression<'a>,
+        ModulePathExpression,
+        BinaryModulePathOperator,
+        Vec<AttributeInstance>,
+        ModulePathExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ModulePathMintypmaxExpression<'a> {
-    ModulePathExpression(ModulePathExpression<'a>),
-    Ternary(ModulePathMintypmaxExpressionTernary<'a>),
+pub enum ModulePathMintypmaxExpression {
+    ModulePathExpression(ModulePathExpression),
+    Ternary(ModulePathMintypmaxExpressionTernary),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathMintypmaxExpressionTernary<'a> {
+pub struct ModulePathMintypmaxExpressionTernary {
     pub nodes: (
-        ModulePathExpression<'a>,
-        Symbol<'a>,
-        ModulePathExpression<'a>,
-        Symbol<'a>,
-        ModulePathExpression<'a>,
+        ModulePathExpression,
+        Symbol,
+        ModulePathExpression,
+        Symbol,
+        ModulePathExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PartSelectRange<'a> {
-    ConstantRange(ConstantRange<'a>),
-    IndexedRange(IndexedRange<'a>),
+pub enum PartSelectRange {
+    ConstantRange(ConstantRange),
+    IndexedRange(IndexedRange),
 }
 
 #[derive(Debug, Node)]
-pub struct IndexedRange<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, ConstantExpression<'a>),
+pub struct IndexedRange {
+    pub nodes: (Expression, Symbol, ConstantExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarExpression<'a> {
-    pub nodes: (ConstantExpression<'a>,),
+pub struct GenvarExpression {
+    pub nodes: (ConstantExpression,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/numbers.rs b/src/parser/expressions/numbers.rs
index 8614f97..e41b6d1 100644
--- a/src/parser/expressions/numbers.rs
+++ b/src/parser/expressions/numbers.rs
@@ -11,153 +11,153 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum Number<'a> {
-    IntegralNumber(IntegralNumber<'a>),
-    RealNumber(RealNumber<'a>),
+pub enum Number {
+    IntegralNumber(IntegralNumber),
+    RealNumber(RealNumber),
 }
 
 #[derive(Debug, Node)]
-pub enum IntegralNumber<'a> {
-    DecimalNumber(DecimalNumber<'a>),
-    OctalNumber(OctalNumber<'a>),
-    BinaryNumber(BinaryNumber<'a>),
-    HexNumber(HexNumber<'a>),
+pub enum IntegralNumber {
+    DecimalNumber(DecimalNumber),
+    OctalNumber(OctalNumber),
+    BinaryNumber(BinaryNumber),
+    HexNumber(HexNumber),
 }
 
 #[derive(Debug, Node)]
-pub enum DecimalNumber<'a> {
-    UnsignedNumber(UnsignedNumber<'a>),
-    BaseUnsigned(DecimalNumberBaseUnsigned<'a>),
-    BaseXNumber(DecimalNumberBaseXNumber<'a>),
-    BaseZNumber(DecimalNumberBaseZNumber<'a>),
+pub enum DecimalNumber {
+    UnsignedNumber(UnsignedNumber),
+    BaseUnsigned(DecimalNumberBaseUnsigned),
+    BaseXNumber(DecimalNumberBaseXNumber),
+    BaseZNumber(DecimalNumberBaseZNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct DecimalNumberBaseUnsigned<'a> {
-    pub nodes: (Option<Size<'a>>, DecimalBase<'a>, UnsignedNumber<'a>),
+pub struct DecimalNumberBaseUnsigned {
+    pub nodes: (Option<Size>, DecimalBase, UnsignedNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct DecimalNumberBaseXNumber<'a> {
-    pub nodes: (Option<Size<'a>>, DecimalBase<'a>, XNumber<'a>),
+pub struct DecimalNumberBaseXNumber {
+    pub nodes: (Option<Size>, DecimalBase, XNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct DecimalNumberBaseZNumber<'a> {
-    pub nodes: (Option<Size<'a>>, DecimalBase<'a>, ZNumber<'a>),
+pub struct DecimalNumberBaseZNumber {
+    pub nodes: (Option<Size>, DecimalBase, ZNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct BinaryNumber<'a> {
-    pub nodes: (Option<Size<'a>>, BinaryBase<'a>, BinaryValue<'a>),
+pub struct BinaryNumber {
+    pub nodes: (Option<Size>, BinaryBase, BinaryValue),
 }
 
 #[derive(Debug, Node)]
-pub struct OctalNumber<'a> {
-    pub nodes: (Option<Size<'a>>, OctalBase<'a>, OctalValue<'a>),
+pub struct OctalNumber {
+    pub nodes: (Option<Size>, OctalBase, OctalValue),
 }
 
 #[derive(Debug, Node)]
-pub struct HexNumber<'a> {
-    pub nodes: (Option<Size<'a>>, HexBase<'a>, HexValue<'a>),
+pub struct HexNumber {
+    pub nodes: (Option<Size>, HexBase, HexValue),
 }
 
 #[derive(Debug, Node)]
-pub enum Sign<'a> {
-    Plus(Symbol<'a>),
-    Minus(Symbol<'a>),
+pub enum Sign {
+    Plus(Symbol),
+    Minus(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct Size<'a> {
-    pub nodes: (NonZeroUnsignedNumber<'a>,),
+pub struct Size {
+    pub nodes: (NonZeroUnsignedNumber,),
 }
 
 #[derive(Debug, Node)]
-pub struct NonZeroUnsignedNumber<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct NonZeroUnsignedNumber {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub enum RealNumber<'a> {
-    FixedPointNumber(FixedPointNumber<'a>),
-    Floating(RealNumberFloating<'a>),
+pub enum RealNumber {
+    FixedPointNumber(FixedPointNumber),
+    Floating(RealNumberFloating),
 }
 
 #[derive(Debug, Node)]
-pub struct RealNumberFloating<'a> {
+pub struct RealNumberFloating {
     pub nodes: (
-        UnsignedNumber<'a>,
-        Option<(Symbol<'a>, UnsignedNumber<'a>)>,
-        Exp<'a>,
-        Option<Sign<'a>>,
-        UnsignedNumber<'a>,
+        UnsignedNumber,
+        Option<(Symbol, UnsignedNumber)>,
+        Exp,
+        Option<Sign>,
+        UnsignedNumber,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct FixedPointNumber<'a> {
-    pub nodes: (UnsignedNumber<'a>, Symbol<'a>, UnsignedNumber<'a>),
+pub struct FixedPointNumber {
+    pub nodes: (UnsignedNumber, Symbol, UnsignedNumber),
 }
 
 #[derive(Debug, Node)]
-pub struct Exp<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct Exp {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct UnsignedNumber<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct UnsignedNumber {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct BinaryValue<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct BinaryValue {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct OctalValue<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct OctalValue {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct HexValue<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct HexValue {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct DecimalBase<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct DecimalBase {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct BinaryBase<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct BinaryBase {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct OctalBase<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct OctalBase {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct HexBase<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct HexBase {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct XNumber<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct XNumber {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct ZNumber<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct ZNumber {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct UnbasedUnsizedLiteral<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct UnbasedUnsizedLiteral {
+    pub nodes: (Symbol,),
 }
 
 // -----------------------------------------------------------------------------
@@ -268,11 +268,12 @@ pub fn non_zero_unsigned_number(s: Span) -> IResult<Span, NonZeroUnsignedNumber>
 }
 
 #[parser]
-pub fn non_zero_unsigned_number_impl(s: Span) -> IResult<Span, Span> {
+pub fn non_zero_unsigned_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a("123456789")(s)?;
-    fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -301,7 +302,9 @@ pub fn real_number_floating(s: Span) -> IResult<Span, RealNumber> {
 #[parser]
 pub fn fixed_point_number(s: Span) -> IResult<Span, FixedPointNumber> {
     let (s, a) = unsigned_number(s)?;
-    let (s, b) = map(tag("."), |x| Symbol { nodes: (x, vec![]) })(s)?;;
+    let (s, b) = map(tag("."), |x: Span| Symbol {
+        nodes: (x.into(), vec![]),
+    })(s)?;
     let (s, c) = unsigned_number(s)?;
     Ok((s, FixedPointNumber { nodes: (a, b, c) }))
 }
@@ -319,11 +322,12 @@ pub fn unsigned_number(s: Span) -> IResult<Span, UnsignedNumber> {
 }
 
 #[parser]
-pub fn unsigned_number_impl(s: Span) -> IResult<Span, Span> {
+pub fn unsigned_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = digit1(s)?;
-    fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -333,11 +337,12 @@ pub fn binary_value(s: Span) -> IResult<Span, BinaryValue> {
 }
 
 #[parser]
-pub fn binary_value_impl(s: Span) -> IResult<Span, Span> {
+pub fn binary_value_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a("01xXzZ?")(s)?;
-    fold_many0(alt((tag("_"), is_a("01xXzZ?"))), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), is_a("01xXzZ?"))), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -347,11 +352,12 @@ pub fn octal_value(s: Span) -> IResult<Span, OctalValue> {
 }
 
 #[parser]
-pub fn octal_value_impl(s: Span) -> IResult<Span, Span> {
+pub fn octal_value_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a("01234567xXzZ?")(s)?;
-    fold_many0(alt((tag("_"), is_a("01234567xXzZ?"))), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), is_a("01234567xXzZ?"))), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -361,13 +367,14 @@ pub fn hex_value(s: Span) -> IResult<Span, HexValue> {
 }
 
 #[parser]
-pub fn hex_value_impl(s: Span) -> IResult<Span, Span> {
+pub fn hex_value_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a("0123456789abcdefABCDEFxXzZ?")(s)?;
-    fold_many0(
+    let (s, a) = fold_many0(
         alt((tag("_"), is_a("0123456789abcdefABCDEFxXzZ?"))),
         a,
         |acc, item| concat(acc, item).unwrap(),
-    )(s)
+    )(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -377,8 +384,9 @@ pub fn decimal_base(s: Span) -> IResult<Span, DecimalBase> {
 }
 
 #[parser]
-pub fn decimal_base_impl(s: Span) -> IResult<Span, Span> {
-    alt((tag_no_case("'d"), tag_no_case("'sd")))(s)
+pub fn decimal_base_impl(s: Span) -> IResult<Span, Locate> {
+    let (s, a) = alt((tag_no_case("'d"), tag_no_case("'sd")))(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -388,8 +396,9 @@ pub fn binary_base(s: Span) -> IResult<Span, BinaryBase> {
 }
 
 #[parser]
-pub fn binary_base_impl(s: Span) -> IResult<Span, Span> {
-    alt((tag_no_case("'b"), tag_no_case("'sb")))(s)
+pub fn binary_base_impl(s: Span) -> IResult<Span, Locate> {
+    let (s, a) = alt((tag_no_case("'b"), tag_no_case("'sb")))(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -399,8 +408,9 @@ pub fn octal_base(s: Span) -> IResult<Span, OctalBase> {
 }
 
 #[parser]
-pub fn octal_base_impl(s: Span) -> IResult<Span, Span> {
-    alt((tag_no_case("'o"), tag_no_case("'so")))(s)
+pub fn octal_base_impl(s: Span) -> IResult<Span, Locate> {
+    let (s, a) = alt((tag_no_case("'o"), tag_no_case("'so")))(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -410,8 +420,9 @@ pub fn hex_base(s: Span) -> IResult<Span, HexBase> {
 }
 
 #[parser]
-pub fn hex_base_impl(s: Span) -> IResult<Span, Span> {
-    alt((tag_no_case("'h"), tag_no_case("'sh")))(s)
+pub fn hex_base_impl(s: Span) -> IResult<Span, Locate> {
+    let (s, a) = alt((tag_no_case("'h"), tag_no_case("'sh")))(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -421,11 +432,12 @@ pub fn x_number(s: Span) -> IResult<Span, XNumber> {
 }
 
 #[parser]
-pub fn x_number_impl(s: Span) -> IResult<Span, Span> {
+pub fn x_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = tag_no_case("x")(s)?;
-    fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -435,11 +447,12 @@ pub fn z_number(s: Span) -> IResult<Span, ZNumber> {
 }
 
 #[parser]
-pub fn z_number_impl(s: Span) -> IResult<Span, Span> {
+pub fn z_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = alt((tag_no_case("z"), tag("?")))(s)?;
-    fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
+    let (s, a) = fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
         concat(acc, item).unwrap()
-    })(s)
+    })(s)?;
+    Ok((s, a.into()))
 }
 
 #[parser]
diff --git a/src/parser/expressions/operators.rs b/src/parser/expressions/operators.rs
index 887e2af..bb519aa 100644
--- a/src/parser/expressions/operators.rs
+++ b/src/parser/expressions/operators.rs
@@ -6,28 +6,28 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct UnaryOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct UnaryOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct BinaryOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct BinaryOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct IncOrDecOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct IncOrDecOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct UnaryModulePathOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct UnaryModulePathOperator {
+    pub nodes: (Symbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct BinaryModulePathOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct BinaryModulePathOperator {
+    pub nodes: (Symbol,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/primaries.rs b/src/parser/expressions/primaries.rs
index 520ea3b..519fbe8 100644
--- a/src/parser/expressions/primaries.rs
+++ b/src/parser/expressions/primaries.rs
@@ -8,255 +8,255 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ConstantPrimary<'a> {
-    PrimaryLiteral(PrimaryLiteral<'a>),
-    PsParameter(ConstantPrimaryPsParameter<'a>),
-    Specparam(ConstantPrimarySpecparam<'a>),
-    GenvarIdentifier(GenvarIdentifier<'a>),
-    FormalPort(ConstantPrimaryFormalPort<'a>),
-    Enum(ConstantPrimaryEnum<'a>),
-    Concatenation(ConstantPrimaryConcatenation<'a>),
-    MultipleConcatenation(ConstantPrimaryMultipleConcatenation<'a>),
-    ConstantFunctionCall(ConstantFunctionCall<'a>),
-    ConstantLetExpression(ConstantLetExpression<'a>),
-    MintypmaxExpression(ConstantPrimaryMintypmaxExpression<'a>),
-    ConstantCast(ConstantCast<'a>),
-    ConstantAssignmentPatternExpression(ConstantAssignmentPatternExpression<'a>),
-    TypeReference(TypeReference<'a>),
-    Null(Keyword<'a>),
+pub enum ConstantPrimary {
+    PrimaryLiteral(PrimaryLiteral),
+    PsParameter(ConstantPrimaryPsParameter),
+    Specparam(ConstantPrimarySpecparam),
+    GenvarIdentifier(GenvarIdentifier),
+    FormalPort(ConstantPrimaryFormalPort),
+    Enum(ConstantPrimaryEnum),
+    Concatenation(ConstantPrimaryConcatenation),
+    MultipleConcatenation(ConstantPrimaryMultipleConcatenation),
+    ConstantFunctionCall(ConstantFunctionCall),
+    ConstantLetExpression(ConstantLetExpression),
+    MintypmaxExpression(ConstantPrimaryMintypmaxExpression),
+    ConstantCast(ConstantCast),
+    ConstantAssignmentPatternExpression(ConstantAssignmentPatternExpression),
+    TypeReference(TypeReference),
+    Null(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryPsParameter<'a> {
-    pub nodes: (PsParameterIdentifier<'a>, ConstantSelect<'a>),
+pub struct ConstantPrimaryPsParameter {
+    pub nodes: (PsParameterIdentifier, ConstantSelect),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimarySpecparam<'a> {
+pub struct ConstantPrimarySpecparam {
     pub nodes: (
-        SpecparamIdentifier<'a>,
-        Option<Bracket<'a, ConstantRangeExpression<'a>>>,
+        SpecparamIdentifier,
+        Option<Bracket< ConstantRangeExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryFormalPort<'a> {
-    pub nodes: (FormalPortIdentifier<'a>, ConstantSelect<'a>),
+pub struct ConstantPrimaryFormalPort {
+    pub nodes: (FormalPortIdentifier, ConstantSelect),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryEnum<'a> {
-    pub nodes: (PackageScopeOrClassScope<'a>, EnumIdentifier<'a>),
+pub struct ConstantPrimaryEnum {
+    pub nodes: (PackageScopeOrClassScope, EnumIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryConcatenation<'a> {
+pub struct ConstantPrimaryConcatenation {
     pub nodes: (
-        ConstantConcatenation<'a>,
-        Option<Bracket<'a, ConstantRangeExpression<'a>>>,
+        ConstantConcatenation,
+        Option<Bracket< ConstantRangeExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryMultipleConcatenation<'a> {
+pub struct ConstantPrimaryMultipleConcatenation {
     pub nodes: (
-        ConstantMultipleConcatenation<'a>,
-        Option<Bracket<'a, ConstantRangeExpression<'a>>>,
+        ConstantMultipleConcatenation,
+        Option<Bracket< ConstantRangeExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantPrimaryMintypmaxExpression<'a> {
-    pub nodes: (Paren<'a, ConstantMintypmaxExpression<'a>>,),
+pub struct ConstantPrimaryMintypmaxExpression {
+    pub nodes: (Paren< ConstantMintypmaxExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ModulePathPrimary<'a> {
-    Number(Number<'a>),
-    Identifier(Identifier<'a>),
-    ModulePathConcatenation(ModulePathConcatenation<'a>),
-    ModulePathMultipleConcatenation(ModulePathMultipleConcatenation<'a>),
-    FunctionSubroutineCall(FunctionSubroutineCall<'a>),
-    Mintypmax(ModulePathPrimaryMintypmax<'a>),
+pub enum ModulePathPrimary {
+    Number(Number),
+    Identifier(Identifier),
+    ModulePathConcatenation(ModulePathConcatenation),
+    ModulePathMultipleConcatenation(ModulePathMultipleConcatenation),
+    FunctionSubroutineCall(FunctionSubroutineCall),
+    Mintypmax(ModulePathPrimaryMintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct ModulePathPrimaryMintypmax<'a> {
-    pub nodes: (Paren<'a, ModulePathMintypmaxExpression<'a>>,),
+pub struct ModulePathPrimaryMintypmax {
+    pub nodes: (Paren< ModulePathMintypmaxExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub enum Primary<'a> {
-    PrimaryLiteral(PrimaryLiteral<'a>),
-    Hierarchical(PrimaryHierarchical<'a>),
-    EmptyUnpackedArrayConcatenation(EmptyUnpackedArrayConcatenation<'a>),
-    Concatenation(PrimaryConcatenation<'a>),
-    MultipleConcatenation(PrimaryMultipleConcatenation<'a>),
-    FunctionSubroutineCall(FunctionSubroutineCall<'a>),
-    LetExpression(LetExpression<'a>),
-    MintypmaxExpression(PrimaryMintypmaxExpression<'a>),
-    Cast(Cast<'a>),
-    AssignmentPatternExpression(AssignmentPatternExpression<'a>),
-    StreamingConcatenation(StreamingConcatenation<'a>),
-    SequenceMethodCall(SequenceMethodCall<'a>),
-    This(Keyword<'a>),
-    Dollar(Symbol<'a>),
-    Null(Keyword<'a>),
+pub enum Primary {
+    PrimaryLiteral(PrimaryLiteral),
+    Hierarchical(PrimaryHierarchical),
+    EmptyUnpackedArrayConcatenation(EmptyUnpackedArrayConcatenation),
+    Concatenation(PrimaryConcatenation),
+    MultipleConcatenation(PrimaryMultipleConcatenation),
+    FunctionSubroutineCall(FunctionSubroutineCall),
+    LetExpression(LetExpression),
+    MintypmaxExpression(PrimaryMintypmaxExpression),
+    Cast(Cast),
+    AssignmentPatternExpression(AssignmentPatternExpression),
+    StreamingConcatenation(StreamingConcatenation),
+    SequenceMethodCall(SequenceMethodCall),
+    This(Keyword),
+    Dollar(Symbol),
+    Null(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct PrimaryHierarchical<'a> {
+pub struct PrimaryHierarchical {
     pub nodes: (
-        Option<ClassQualifierOrPackageScope<'a>>,
-        HierarchicalIdentifier<'a>,
-        Select<'a>,
+        Option<ClassQualifierOrPackageScope>,
+        HierarchicalIdentifier,
+        Select,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PrimaryConcatenation<'a> {
-    pub nodes: (Concatenation<'a>, Option<Bracket<'a, RangeExpression<'a>>>),
+pub struct PrimaryConcatenation {
+    pub nodes: (Concatenation, Option<Bracket< RangeExpression>>),
 }
 
 #[derive(Debug, Node)]
-pub struct PrimaryMultipleConcatenation<'a> {
+pub struct PrimaryMultipleConcatenation {
     pub nodes: (
-        MultipleConcatenation<'a>,
-        Option<Bracket<'a, RangeExpression<'a>>>,
+        MultipleConcatenation,
+        Option<Bracket< RangeExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PrimaryMintypmaxExpression<'a> {
-    pub nodes: (Paren<'a, MintypmaxExpression<'a>>,),
+pub struct PrimaryMintypmaxExpression {
+    pub nodes: (Paren< MintypmaxExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassQualifierOrPackageScope<'a> {
-    ClassQualifier(ClassQualifier<'a>),
-    PackageScope(PackageScope<'a>),
+pub enum ClassQualifierOrPackageScope {
+    ClassQualifier(ClassQualifier),
+    PackageScope(PackageScope),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassQualifier<'a> {
+pub struct ClassQualifier {
     pub nodes: (
-        Option<Local<'a>>,
-        Option<ImplicitClassHandleOrClassScope<'a>>,
+        Option<Local>,
+        Option<ImplicitClassHandleOrClassScope>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum RangeExpression<'a> {
-    Expression(Expression<'a>),
-    PartSelectRange(PartSelectRange<'a>),
+pub enum RangeExpression {
+    Expression(Expression),
+    PartSelectRange(PartSelectRange),
 }
 
 #[derive(Debug, Node)]
-pub enum PrimaryLiteral<'a> {
-    Number(Number<'a>),
-    TimeLiteral(TimeLiteral<'a>),
-    UnbasedUnsizedLiteral(UnbasedUnsizedLiteral<'a>),
-    StringLiteral(StringLiteral<'a>),
+pub enum PrimaryLiteral {
+    Number(Number),
+    TimeLiteral(TimeLiteral),
+    UnbasedUnsizedLiteral(UnbasedUnsizedLiteral),
+    StringLiteral(StringLiteral),
 }
 
 #[derive(Debug, Node)]
-pub enum TimeLiteral<'a> {
-    Unsigned(TimeLiteralUnsigned<'a>),
-    FixedPoint(TimeLiteralFixedPoint<'a>),
+pub enum TimeLiteral {
+    Unsigned(TimeLiteralUnsigned),
+    FixedPoint(TimeLiteralFixedPoint),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeLiteralUnsigned<'a> {
-    pub nodes: (UnsignedNumber<'a>, TimeUnit<'a>),
+pub struct TimeLiteralUnsigned {
+    pub nodes: (UnsignedNumber, TimeUnit),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeLiteralFixedPoint<'a> {
-    pub nodes: (FixedPointNumber<'a>, TimeUnit<'a>),
+pub struct TimeLiteralFixedPoint {
+    pub nodes: (FixedPointNumber, TimeUnit),
 }
 
 #[derive(Debug, Node)]
-pub enum TimeUnit<'a> {
-    S(Keyword<'a>),
-    MS(Keyword<'a>),
-    US(Keyword<'a>),
-    NS(Keyword<'a>),
-    PS(Keyword<'a>),
-    FS(Keyword<'a>),
+pub enum TimeUnit {
+    S(Keyword),
+    MS(Keyword),
+    US(Keyword),
+    NS(Keyword),
+    PS(Keyword),
+    FS(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum ImplicitClassHandle<'a> {
-    This(Keyword<'a>),
-    Super(Keyword<'a>),
-    ThisSuper((Keyword<'a>, Symbol<'a>, Keyword<'a>)),
+pub enum ImplicitClassHandle {
+    This(Keyword),
+    Super(Keyword),
+    ThisSuper((Keyword, Symbol, Keyword)),
 }
 
 #[derive(Debug, Node)]
-pub struct BitSelect<'a> {
-    nodes: (Vec<Bracket<'a, Expression<'a>>>,),
+pub struct BitSelect {
+    nodes: (Vec<Bracket< Expression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct Select<'a> {
+pub struct Select {
     pub nodes: (
         Option<(
-            Vec<(Symbol<'a>, MemberIdentifier<'a>, BitSelect<'a>)>,
-            Symbol<'a>,
-            MemberIdentifier<'a>,
+            Vec<(Symbol, MemberIdentifier, BitSelect)>,
+            Symbol,
+            MemberIdentifier,
         )>,
-        BitSelect<'a>,
-        Option<Bracket<'a, PartSelectRange<'a>>>,
+        BitSelect,
+        Option<Bracket< PartSelectRange>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NonrangeSelect<'a> {
+pub struct NonrangeSelect {
     pub nodes: (
         Option<(
-            Vec<(Symbol<'a>, MemberIdentifier<'a>, BitSelect<'a>)>,
-            Symbol<'a>,
-            MemberIdentifier<'a>,
+            Vec<(Symbol, MemberIdentifier, BitSelect)>,
+            Symbol,
+            MemberIdentifier,
         )>,
-        BitSelect<'a>,
+        BitSelect,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantBitSelect<'a> {
-    nodes: (Vec<Bracket<'a, ConstantExpression<'a>>>,),
+pub struct ConstantBitSelect {
+    nodes: (Vec<Bracket< ConstantExpression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantSelect<'a> {
+pub struct ConstantSelect {
     pub nodes: (
         Option<(
-            Vec<(Symbol<'a>, MemberIdentifier<'a>, ConstantBitSelect<'a>)>,
-            Symbol<'a>,
-            MemberIdentifier<'a>,
+            Vec<(Symbol, MemberIdentifier, ConstantBitSelect)>,
+            Symbol,
+            MemberIdentifier,
         )>,
-        ConstantBitSelect<'a>,
-        Option<Bracket<'a, ConstantPartSelectRange<'a>>>,
+        ConstantBitSelect,
+        Option<Bracket< ConstantPartSelectRange>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantCast<'a> {
+pub struct ConstantCast {
     pub nodes: (
-        CastingType<'a>,
-        Symbol<'a>,
-        Paren<'a, ConstantExpression<'a>>,
+        CastingType,
+        Symbol,
+        Paren< ConstantExpression>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstantLetExpression<'a> {
-    pub nodes: (LetExpression<'a>,),
+pub struct ConstantLetExpression {
+    pub nodes: (LetExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct Cast<'a> {
-    pub nodes: (CastingType<'a>, Symbol<'a>, Paren<'a, Expression<'a>>),
+pub struct Cast {
+    pub nodes: (CastingType, Symbol, Paren< Expression>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/strings.rs b/src/parser/expressions/strings.rs
index 12e753e..88fefc0 100644
--- a/src/parser/expressions/strings.rs
+++ b/src/parser/expressions/strings.rs
@@ -9,8 +9,8 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct StringLiteral<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct StringLiteral {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 // -----------------------------------------------------------------------------
@@ -22,7 +22,7 @@ pub fn string_literal(s: Span) -> IResult<Span, StringLiteral> {
 }
 
 #[parser]
-pub fn string_literal_impl(s: Span) -> IResult<Span, Span> {
+pub fn string_literal_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = tag("\"")(s)?;
     let (s, b) = many1(pair(is_not("\\\""), opt(pair(tag("\\"), take(1usize)))))(s)?;
     let (s, c) = tag("\"")(s)?;
@@ -52,7 +52,7 @@ pub fn string_literal_impl(s: Span) -> IResult<Span, Span> {
     let a = concat(a, b).unwrap();
     let a = concat(a, c).unwrap();
 
-    Ok((s, a))
+    Ok((s, a.into()))
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/expressions/subroutine_calls.rs b/src/parser/expressions/subroutine_calls.rs
index e4266bc..41867ca 100644
--- a/src/parser/expressions/subroutine_calls.rs
+++ b/src/parser/expressions/subroutine_calls.rs
@@ -9,177 +9,177 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ConstantFunctionCall<'a> {
-    pub nodes: (FunctionSubroutineCall<'a>,),
+pub struct ConstantFunctionCall {
+    pub nodes: (FunctionSubroutineCall,),
 }
 
 #[derive(Debug, Node)]
-pub struct TfCall<'a> {
+pub struct TfCall {
     pub nodes: (
-        PsOrHierarchicalTfIdentifier<'a>,
-        Vec<AttributeInstance<'a>>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
+        PsOrHierarchicalTfIdentifier,
+        Vec<AttributeInstance>,
+        Option<Paren< ListOfArguments>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum SystemTfCall<'a> {
-    ArgOptionl(SystemTfCallArgOptional<'a>),
-    ArgDataType(SystemTfCallArgDataType<'a>),
-    ArgExpression(SystemTfCallArgExpression<'a>),
+pub enum SystemTfCall {
+    ArgOptionl(SystemTfCallArgOptional),
+    ArgDataType(SystemTfCallArgDataType),
+    ArgExpression(SystemTfCallArgExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct SystemTfCallArgOptional<'a> {
+pub struct SystemTfCallArgOptional {
     pub nodes: (
-        SystemTfIdentifier<'a>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
+        SystemTfIdentifier,
+        Option<Paren< ListOfArguments>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SystemTfCallArgDataType<'a> {
+pub struct SystemTfCallArgDataType {
     pub nodes: (
-        SystemTfIdentifier<'a>,
-        Paren<'a, (DataType<'a>, Option<(Symbol<'a>, Expression<'a>)>)>,
+        SystemTfIdentifier,
+        Paren< (DataType, Option<(Symbol, Expression)>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SystemTfCallArgExpression<'a> {
+pub struct SystemTfCallArgExpression {
     pub nodes: (
-        SystemTfIdentifier<'a>,
+        SystemTfIdentifier,
         Paren<
-            'a,
+            
             (
-                List<Symbol<'a>, Option<Expression<'a>>>,
-                Option<(Symbol<'a>, Option<ClockingEvent<'a>>)>,
+                List<Symbol, Option<Expression>>,
+                Option<(Symbol, Option<ClockingEvent>)>,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum SubroutineCall<'a> {
-    TfCall(Box<TfCall<'a>>),
-    SystemTfCall(Box<SystemTfCall<'a>>),
-    MethodCall(Box<MethodCall<'a>>),
-    Randomize(Box<SubroutineCallRandomize<'a>>),
+pub enum SubroutineCall {
+    TfCall(Box<TfCall>),
+    SystemTfCall(Box<SystemTfCall>),
+    MethodCall(Box<MethodCall>),
+    Randomize(Box<SubroutineCallRandomize>),
 }
 
 #[derive(Debug, Node)]
-pub struct SubroutineCallRandomize<'a> {
-    pub nodes: (Option<(Keyword<'a>, Symbol<'a>)>, RandomizeCall<'a>),
+pub struct SubroutineCallRandomize {
+    pub nodes: (Option<(Keyword, Symbol)>, RandomizeCall),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionSubroutineCall<'a> {
-    pub nodes: (SubroutineCall<'a>,),
+pub struct FunctionSubroutineCall {
+    pub nodes: (SubroutineCall,),
 }
 
 #[derive(Debug, Node)]
-pub enum ListOfArguments<'a> {
-    Ordered(ListOfArgumentsOrdered<'a>),
-    Named(ListOfArgumentsNamed<'a>),
+pub enum ListOfArguments {
+    Ordered(ListOfArgumentsOrdered),
+    Named(ListOfArgumentsNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfArgumentsOrdered<'a> {
+pub struct ListOfArgumentsOrdered {
     pub nodes: (
-        List<Symbol<'a>, Option<Expression<'a>>>,
+        List<Symbol, Option<Expression>>,
         Vec<(
-            Symbol<'a>,
-            Symbol<'a>,
-            Identifier<'a>,
-            Paren<'a, Option<Expression<'a>>>,
+            Symbol,
+            Symbol,
+            Identifier,
+            Paren< Option<Expression>>,
         )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfArgumentsNamed<'a> {
+pub struct ListOfArgumentsNamed {
     pub nodes: (
-        Symbol<'a>,
-        Identifier<'a>,
-        Paren<'a, Option<Expression<'a>>>,
+        Symbol,
+        Identifier,
+        Paren< Option<Expression>>,
         Vec<(
-            Symbol<'a>,
-            Symbol<'a>,
-            Identifier<'a>,
-            Paren<'a, Option<Expression<'a>>>,
+            Symbol,
+            Symbol,
+            Identifier,
+            Paren< Option<Expression>>,
         )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct MethodCall<'a> {
-    pub nodes: (MethodCallRoot<'a>, Symbol<'a>, MethodCallBody<'a>),
+pub struct MethodCall {
+    pub nodes: (MethodCallRoot, Symbol, MethodCallBody),
 }
 
 #[derive(Debug, Node)]
-pub enum MethodCallBody<'a> {
-    User(MethodCallBodyUser<'a>),
-    BuiltInMethodCall(BuiltInMethodCall<'a>),
+pub enum MethodCallBody {
+    User(MethodCallBodyUser),
+    BuiltInMethodCall(BuiltInMethodCall),
 }
 
 #[derive(Debug, Node)]
-pub struct MethodCallBodyUser<'a> {
+pub struct MethodCallBodyUser {
     pub nodes: (
-        MethodIdentifier<'a>,
-        Vec<AttributeInstance<'a>>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
+        MethodIdentifier,
+        Vec<AttributeInstance>,
+        Option<Paren< ListOfArguments>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum BuiltInMethodCall<'a> {
-    ArrayManipulationCall(ArrayManipulationCall<'a>),
-    RandomizeCall(RandomizeCall<'a>),
+pub enum BuiltInMethodCall {
+    ArrayManipulationCall(ArrayManipulationCall),
+    RandomizeCall(RandomizeCall),
 }
 
 #[derive(Debug, Node)]
-pub struct ArrayManipulationCall<'a> {
+pub struct ArrayManipulationCall {
     pub nodes: (
-        ArrayMethodName<'a>,
-        Vec<AttributeInstance<'a>>,
-        Option<Paren<'a, ListOfArguments<'a>>>,
-        Option<(Keyword<'a>, Paren<'a, Expression<'a>>)>,
+        ArrayMethodName,
+        Vec<AttributeInstance>,
+        Option<Paren< ListOfArguments>>,
+        Option<(Keyword, Paren< Expression>)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RandomizeCall<'a> {
+pub struct RandomizeCall {
     pub nodes: (
-        Keyword<'a>,
-        Vec<AttributeInstance<'a>>,
-        Option<Paren<'a, Option<VariableIdentifierListOrNull<'a>>>>,
+        Keyword,
+        Vec<AttributeInstance>,
+        Option<Paren< Option<VariableIdentifierListOrNull>>>,
         Option<(
-            Keyword<'a>,
-            Option<Paren<'a, Option<IdentifierList<'a>>>>,
-            ConstraintBlock<'a>,
+            Keyword,
+            Option<Paren< Option<IdentifierList>>>,
+            ConstraintBlock,
         )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum VariableIdentifierListOrNull<'a> {
-    VariableIdentifierList(VariableIdentifierList<'a>),
-    Null(Keyword<'a>),
+pub enum VariableIdentifierListOrNull {
+    VariableIdentifierList(VariableIdentifierList),
+    Null(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum MethodCallRoot<'a> {
-    Primary(Primary<'a>),
-    ImplicitClassHandle(ImplicitClassHandle<'a>),
+pub enum MethodCallRoot {
+    Primary(Primary),
+    ImplicitClassHandle(ImplicitClassHandle),
 }
 
 #[derive(Debug, Node)]
-pub enum ArrayMethodName<'a> {
-    MethodIdentifier(MethodIdentifier<'a>),
-    Unique(Keyword<'a>),
-    And(Keyword<'a>),
-    Or(Keyword<'a>),
-    Xor(Keyword<'a>),
+pub enum ArrayMethodName {
+    MethodIdentifier(MethodIdentifier),
+    Unique(Keyword),
+    And(Keyword),
+    Or(Keyword),
+    Xor(Keyword),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/general/attributes.rs b/src/parser/general/attributes.rs
index d15863c..c5f1de4 100644
--- a/src/parser/general/attributes.rs
+++ b/src/parser/general/attributes.rs
@@ -7,13 +7,13 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct AttributeInstance<'a> {
-    pub nodes: (Symbol<'a>, List<Symbol<'a>, AttrSpec<'a>>, Symbol<'a>),
+pub struct AttributeInstance {
+    pub nodes: (Symbol, List<Symbol, AttrSpec>, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct AttrSpec<'a> {
-    pub nodes: (Identifier<'a>, Option<(Symbol<'a>, ConstantExpression<'a>)>),
+pub struct AttrSpec {
+    pub nodes: (Identifier, Option<(Symbol, ConstantExpression)>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/general/comments.rs b/src/parser/general/comments.rs
index 49828f2..b185cca 100644
--- a/src/parser/general/comments.rs
+++ b/src/parser/general/comments.rs
@@ -7,8 +7,8 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct Comment<'a> {
-    nodes: (Span<'a>,),
+pub struct Comment {
+    nodes: (Locate,),
 }
 
 // -----------------------------------------------------------------------------
@@ -23,7 +23,7 @@ pub fn one_line_comment(s: Span) -> IResult<Span, Comment> {
     let (s, a) = tag("//")(s)?;
     let (s, b) = is_not("\n")(s)?;
     let a = concat(a, b).unwrap();
-    Ok((s, Comment { nodes: (a,) }))
+    Ok((s, Comment { nodes: (a.into(),) }))
 }
 
 #[parser]
@@ -33,7 +33,7 @@ pub fn block_comment(s: Span) -> IResult<Span, Comment> {
     let (s, c) = tag("*/")(s)?;
     let a = concat(a, b).unwrap();
     let a = concat(a, c).unwrap();
-    Ok((s, Comment { nodes: (a,) }))
+    Ok((s, Comment { nodes: (a.into(),) }))
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/general/identifiers.rs b/src/parser/general/identifiers.rs
index 3adb100..878895f 100644
--- a/src/parser/general/identifiers.rs
+++ b/src/parser/general/identifiers.rs
@@ -15,532 +15,526 @@ pub const AZ09_: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ012
 pub const AZ09_DOLLAR: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_$";
 
 #[derive(Debug, Node)]
-pub struct ArrayIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ArrayIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct BlockIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct BlockIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct BinIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct BinIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CIdentifier<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct CIdentifier {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct CellIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct CellIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct CheckerIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ClassIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassVariableIdentifier<'a> {
-    pub nodes: (VariableIdentifier<'a>,),
+pub struct ClassVariableIdentifier {
+    pub nodes: (VariableIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ClockingIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ClockingIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ConfigIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ConstIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ConstraintIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CovergroupIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct CovergroupIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CovergroupVariableIdentifier<'a> {
-    pub nodes: (VariableIdentifier<'a>,),
+pub struct CovergroupVariableIdentifier {
+    pub nodes: (VariableIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CoverPointIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct CoverPointIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct CrossIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct CrossIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct DynamicArrayVariableIdentifier<'a> {
-    pub nodes: (VariableIdentifier<'a>,),
+pub struct DynamicArrayVariableIdentifier {
+    pub nodes: (VariableIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct EnumIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct EnumIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct EscapedIdentifier<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct EscapedIdentifier {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct FormalIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct FormalIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct FormalPortIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct FormalPortIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct FunctionIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct FunctionIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct GenerateBlockIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct GenerateBlockIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct GenvarIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalArrayIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalArrayIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalBlockIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalBlockIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalEventIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalEventIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalIdentifier<'a> {
+pub struct HierarchicalIdentifier {
     pub nodes: (
-        Option<Root<'a>>,
-        Vec<(Identifier<'a>, ConstantBitSelect<'a>, Symbol<'a>)>,
-        Identifier<'a>,
+        Option<Root>,
+        Vec<(Identifier, ConstantBitSelect, Symbol)>,
+        Identifier,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Root<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>),
+pub struct Root {
+    pub nodes: (Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalNetIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalNetIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalParameterIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalParameterIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalPropertyIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalPropertyIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalSequenceIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalSequenceIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalTaskIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalTaskIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalTfIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalTfIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalVariableIdentifier<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>,),
+pub struct HierarchicalVariableIdentifier {
+    pub nodes: (HierarchicalIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub enum Identifier<'a> {
-    SimpleIdentifier(SimpleIdentifier<'a>),
-    EscapedIdentifier(EscapedIdentifier<'a>),
+pub enum Identifier {
+    SimpleIdentifier(SimpleIdentifier),
+    EscapedIdentifier(EscapedIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct IndexVariableIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct IndexVariableIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct InterfaceIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceInstanceIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct InterfaceInstanceIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct InoutPortIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct InoutPortIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct InputPortIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct InputPortIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct InstanceIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct InstanceIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct LibraryIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct LibraryIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct MemberIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct MemberIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct MethodIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct MethodIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ModportIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ModportIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ModuleIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct NetIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct NetIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct NetTypeIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct NetTypeIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputPortIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct OutputPortIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct PackageIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub enum PackageScope<'a> {
-    Package(PackageScopePackage<'a>),
-    Unit(Unit<'a>),
+pub enum PackageScope {
+    Package(PackageScopePackage),
+    Unit(Unit),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageScopePackage<'a> {
-    pub nodes: (PackageIdentifier<'a>, Symbol<'a>),
+pub struct PackageScopePackage {
+    pub nodes: (PackageIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct Unit<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>),
+pub struct Unit {
+    pub nodes: (Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ParameterIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct PortIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct PortIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ProductionIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ProductionIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct ProgramIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct PropertyIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct PropertyIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct PsClassIdentifier<'a> {
-    pub nodes: (Option<PackageScope<'a>>, ClassIdentifier<'a>),
+pub struct PsClassIdentifier {
+    pub nodes: (Option<PackageScope>, ClassIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsCovergroupIdentifier<'a> {
-    pub nodes: (Option<PackageScope<'a>>, CovergroupIdentifier<'a>),
+pub struct PsCovergroupIdentifier {
+    pub nodes: (Option<PackageScope>, CovergroupIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsCheckerIdentifier<'a> {
-    pub nodes: (Option<PackageScope<'a>>, CheckerIdentifier<'a>),
+pub struct PsCheckerIdentifier {
+    pub nodes: (Option<PackageScope>, CheckerIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsIdentifier<'a> {
-    pub nodes: (Option<PackageScope<'a>>, Identifier<'a>),
+pub struct PsIdentifier {
+    pub nodes: (Option<PackageScope>, Identifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalArrayIdentifier<'a> {
+pub struct PsOrHierarchicalArrayIdentifier {
     pub nodes: (
-        Option<ImplicitClassHandleOrClassScopeOrPackageScope<'a>>,
-        HierarchicalArrayIdentifier<'a>,
+        Option<ImplicitClassHandleOrClassScopeOrPackageScope>,
+        HierarchicalArrayIdentifier,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PsOrHierarchicalNetIdentifier<'a> {
-    PackageScope(PsOrHierarchicalNetIdentifierPackageScope<'a>),
-    HierarchicalNetIdentifier(HierarchicalNetIdentifier<'a>),
+pub enum PsOrHierarchicalNetIdentifier {
+    PackageScope(PsOrHierarchicalNetIdentifierPackageScope),
+    HierarchicalNetIdentifier(HierarchicalNetIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalNetIdentifierPackageScope<'a> {
-    pub nodes: (Option<PackageScope<'a>>, NetIdentifier<'a>),
+pub struct PsOrHierarchicalNetIdentifierPackageScope {
+    pub nodes: (Option<PackageScope>, NetIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalNetIdentifierHierarchical<'a> {
-    pub nodes: (HierarchicalNetIdentifier<'a>),
+pub struct PsOrHierarchicalNetIdentifierHierarchical {
+    pub nodes: (HierarchicalNetIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum PsOrHierarchicalPropertyIdentifier<'a> {
-    PackageScope(PsOrHierarchicalPropertyIdentifierPackageScope<'a>),
-    HierarchicalPropertyIdentifier(HierarchicalPropertyIdentifier<'a>),
+pub enum PsOrHierarchicalPropertyIdentifier {
+    PackageScope(PsOrHierarchicalPropertyIdentifierPackageScope),
+    HierarchicalPropertyIdentifier(HierarchicalPropertyIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalPropertyIdentifierPackageScope<'a> {
-    pub nodes: (Option<PackageScope<'a>>, PropertyIdentifier<'a>),
+pub struct PsOrHierarchicalPropertyIdentifierPackageScope {
+    pub nodes: (Option<PackageScope>, PropertyIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalPropertyIdentifierHierarchical<'a> {
-    pub nodes: (HierarchicalPropertyIdentifier<'a>),
+pub struct PsOrHierarchicalPropertyIdentifierHierarchical {
+    pub nodes: (HierarchicalPropertyIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum PsOrHierarchicalSequenceIdentifier<'a> {
-    PackageScope(PsOrHierarchicalSequenceIdentifierPackageScope<'a>),
-    HierarchicalSequenceIdentifier(HierarchicalSequenceIdentifier<'a>),
+pub enum PsOrHierarchicalSequenceIdentifier {
+    PackageScope(PsOrHierarchicalSequenceIdentifierPackageScope),
+    HierarchicalSequenceIdentifier(HierarchicalSequenceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalSequenceIdentifierPackageScope<'a> {
-    pub nodes: (Option<PackageScope<'a>>, SequenceIdentifier<'a>),
+pub struct PsOrHierarchicalSequenceIdentifierPackageScope {
+    pub nodes: (Option<PackageScope>, SequenceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalSequenceIdentifierHierarchical<'a> {
-    pub nodes: (HierarchicalSequenceIdentifier<'a>),
+pub struct PsOrHierarchicalSequenceIdentifierHierarchical {
+    pub nodes: (HierarchicalSequenceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum PsOrHierarchicalTfIdentifier<'a> {
-    PackageScope(PsOrHierarchicalTfIdentifierPackageScope<'a>),
-    HierarchicalTfIdentifier(HierarchicalTfIdentifier<'a>),
+pub enum PsOrHierarchicalTfIdentifier {
+    PackageScope(PsOrHierarchicalTfIdentifierPackageScope),
+    HierarchicalTfIdentifier(HierarchicalTfIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalTfIdentifierPackageScope<'a> {
-    pub nodes: (Option<PackageScope<'a>>, TfIdentifier<'a>),
+pub struct PsOrHierarchicalTfIdentifierPackageScope {
+    pub nodes: (Option<PackageScope>, TfIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsOrHierarchicalTfIdentifierHierarchical<'a> {
-    pub nodes: (HierarchicalTfIdentifier<'a>),
+pub struct PsOrHierarchicalTfIdentifierHierarchical {
+    pub nodes: (HierarchicalTfIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum PsParameterIdentifier<'a> {
-    Scope(PsParameterIdentifierScope<'a>),
-    Generate(PsParameterIdentifierGenerate<'a>),
+pub enum PsParameterIdentifier {
+    Scope(PsParameterIdentifierScope),
+    Generate(PsParameterIdentifierGenerate),
 }
 
 #[derive(Debug, Node)]
-pub struct PsParameterIdentifierScope<'a> {
-    pub nodes: (
-        Option<PackageScopeOrClassScope<'a>>,
-        ParameterIdentifier<'a>,
-    ),
+pub struct PsParameterIdentifierScope {
+    pub nodes: (Option<PackageScopeOrClassScope>, ParameterIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct PsParameterIdentifierGenerate<'a> {
+pub struct PsParameterIdentifierGenerate {
     pub nodes: (
         Vec<(
-            GenerateBlockIdentifier<'a>,
-            Option<Bracket<'a, ConstantExpression<'a>>>,
-            Symbol<'a>,
+            GenerateBlockIdentifier,
+            Option<Bracket<ConstantExpression>>,
+            Symbol,
         )>,
-        ParameterIdentifier<'a>,
+        ParameterIdentifier,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PsTypeIdentifier<'a> {
-    pub nodes: (
-        Option<LocalOrPackageScopeOrClassScope<'a>>,
-        TypeIdentifier<'a>,
-    ),
+pub struct PsTypeIdentifier {
+    pub nodes: (Option<LocalOrPackageScopeOrClassScope>, TypeIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum LocalOrPackageScopeOrClassScope<'a> {
-    Local(Local<'a>),
-    PackageScope(PackageScope<'a>),
-    ClassScope(ClassScope<'a>),
+pub enum LocalOrPackageScopeOrClassScope {
+    Local(Local),
+    PackageScope(PackageScope),
+    ClassScope(ClassScope),
 }
 
 #[derive(Debug, Node)]
-pub struct Local<'a> {
-    pub nodes: (Keyword<'a>, Symbol<'a>),
+pub struct Local {
+    pub nodes: (Keyword, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct SequenceIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct SequenceIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct SignalIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct SignalIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct SimpleIdentifier<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct SimpleIdentifier {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct SpecparamIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct SpecparamIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct SystemTfIdentifier<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct SystemTfIdentifier {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct TaskIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct TaskIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct TfIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct TfIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct TerminalIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct TerminalIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct TopmoduleIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct TopmoduleIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct TypeIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct TypeIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct UdpIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct VariableIdentifier<'a> {
-    pub nodes: (Identifier<'a>,),
+pub struct VariableIdentifier {
+    pub nodes: (Identifier,),
 }
 
 #[derive(Debug, Node)]
-pub enum ImplicitClassHandleOrClassScopeOrPackageScope<'a> {
-    ImplicitClassHandle((ImplicitClassHandle<'a>, Symbol<'a>)),
-    ClassScope(ClassScope<'a>),
-    PackageScope(PackageScope<'a>),
+pub enum ImplicitClassHandleOrClassScopeOrPackageScope {
+    ImplicitClassHandle((ImplicitClassHandle, Symbol)),
+    ClassScope(ClassScope),
+    PackageScope(PackageScope),
 }
 
 #[derive(Debug, Node)]
-pub enum ImplicitClassHandleOrPackageScope<'a> {
-    ImplicitClassHandle((ImplicitClassHandle<'a>, Symbol<'a>)),
-    PackageScope(PackageScope<'a>),
+pub enum ImplicitClassHandleOrPackageScope {
+    ImplicitClassHandle((ImplicitClassHandle, Symbol)),
+    PackageScope(PackageScope),
 }
 
 #[derive(Debug, Node)]
-pub enum ImplicitClassHandleOrClassScope<'a> {
-    ImplicitClassHandle((ImplicitClassHandle<'a>, Symbol<'a>)),
-    ClassScope(ClassScope<'a>),
+pub enum ImplicitClassHandleOrClassScope {
+    ImplicitClassHandle((ImplicitClassHandle, Symbol)),
+    ClassScope(ClassScope),
 }
 
 #[derive(Debug, Node)]
-pub enum PackageScopeOrClassScope<'a> {
-    PackageScope(PackageScope<'a>),
-    ClassScope(ClassScope<'a>),
+pub enum PackageScopeOrClassScope {
+    PackageScope(PackageScope),
+    ClassScope(ClassScope),
 }
 
 // -----------------------------------------------------------------------------
@@ -570,7 +564,7 @@ pub fn c_identifier(s: Span) -> IResult<Span, CIdentifier> {
 }
 
 #[parser]
-pub fn c_identifier_impl(s: Span) -> IResult<Span, Span> {
+pub fn c_identifier_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a(AZ_)(s)?;
     let (s, b) = opt(is_a(AZ09_))(s)?;
     let a = if let Some(b) = b {
@@ -581,7 +575,7 @@ pub fn c_identifier_impl(s: Span) -> IResult<Span, Span> {
     if is_keyword(&a) {
         Err(Err::Error(make_error(s, ErrorKind::Fix)))
     } else {
-        Ok((s, a))
+        Ok((s, a.into()))
     }
 }
 
@@ -676,11 +670,11 @@ pub fn escaped_identifier(s: Span) -> IResult<Span, EscapedIdentifier> {
 }
 
 #[parser]
-pub fn escaped_identifier_impl(s: Span) -> IResult<Span, Span> {
+pub fn escaped_identifier_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = tag("\\")(s)?;
     let (s, b) = is_not(" \t\r\n")(s)?;
     let a = concat(a, b).unwrap();
-    Ok((s, a))
+    Ok((s, a.into()))
 }
 
 #[parser]
@@ -1135,7 +1129,7 @@ pub fn simple_identifier(s: Span) -> IResult<Span, SimpleIdentifier> {
 }
 
 #[parser]
-pub fn simple_identifier_impl(s: Span) -> IResult<Span, Span> {
+pub fn simple_identifier_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = is_a(AZ_)(s)?;
     let (s, b) = opt(is_a(AZ09_DOLLAR))(s)?;
     let a = if let Some(b) = b {
@@ -1146,7 +1140,7 @@ pub fn simple_identifier_impl(s: Span) -> IResult<Span, Span> {
     if is_keyword(&a) {
         Err(Err::Error(make_error(s, ErrorKind::Fix)))
     } else {
-        Ok((s, a))
+        Ok((s, a.into()))
     }
 }
 
@@ -1163,11 +1157,11 @@ pub fn system_tf_identifier(s: Span) -> IResult<Span, SystemTfIdentifier> {
 }
 
 #[parser]
-pub fn system_tf_identifier_impl(s: Span) -> IResult<Span, Span> {
+pub fn system_tf_identifier_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = tag("$")(s)?;
     let (s, b) = is_a(AZ09_DOLLAR)(s)?;
     let a = concat(a, b).unwrap();
-    Ok((s, a))
+    Ok((s, a.into()))
 }
 
 #[parser]
diff --git a/src/parser/instantiations/checker_instantiation.rs b/src/parser/instantiations/checker_instantiation.rs
index ed951c1..2ca7fc1 100644
--- a/src/parser/instantiations/checker_instantiation.rs
+++ b/src/parser/instantiations/checker_instantiation.rs
@@ -8,55 +8,55 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct CheckerInstantiation<'a> {
+pub struct CheckerInstantiation {
     pub nodes: (
-        PsCheckerIdentifier<'a>,
-        NameOfInstance<'a>,
-        Paren<'a, Option<ListOfCheckerPortConnections<'a>>>,
-        Symbol<'a>,
+        PsCheckerIdentifier,
+        NameOfInstance,
+        Paren< Option<ListOfCheckerPortConnections>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ListOfCheckerPortConnections<'a> {
-    Ordered(ListOfCheckerPortConnectionsOrdered<'a>),
-    Named(ListOfCheckerPortConnectionsNamed<'a>),
+pub enum ListOfCheckerPortConnections {
+    Ordered(ListOfCheckerPortConnectionsOrdered),
+    Named(ListOfCheckerPortConnectionsNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfCheckerPortConnectionsOrdered<'a> {
-    pub nodes: (List<Symbol<'a>, OrderedCheckerPortConnection<'a>>,),
+pub struct ListOfCheckerPortConnectionsOrdered {
+    pub nodes: (List<Symbol, OrderedCheckerPortConnection>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfCheckerPortConnectionsNamed<'a> {
-    pub nodes: (List<Symbol<'a>, NamedCheckerPortConnection<'a>>,),
+pub struct ListOfCheckerPortConnectionsNamed {
+    pub nodes: (List<Symbol, NamedCheckerPortConnection>,),
 }
 
 #[derive(Debug, Node)]
-pub struct OrderedCheckerPortConnection<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Option<PropertyActualArg<'a>>),
+pub struct OrderedCheckerPortConnection {
+    pub nodes: (Vec<AttributeInstance>, Option<PropertyActualArg>),
 }
 
 #[derive(Debug, Node)]
-pub enum NamedCheckerPortConnection<'a> {
-    Identifier(NamedCheckerPortConnectionIdentifier<'a>),
-    Asterisk(NamedCheckerPortConnectionAsterisk<'a>),
+pub enum NamedCheckerPortConnection {
+    Identifier(NamedCheckerPortConnectionIdentifier),
+    Asterisk(NamedCheckerPortConnectionAsterisk),
 }
 
 #[derive(Debug, Node)]
-pub struct NamedCheckerPortConnectionIdentifier<'a> {
+pub struct NamedCheckerPortConnectionIdentifier {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Symbol<'a>,
-        FormalPortIdentifier<'a>,
-        Option<Paren<'a, Option<PropertyActualArg<'a>>>>,
+        Vec<AttributeInstance>,
+        Symbol,
+        FormalPortIdentifier,
+        Option<Paren< Option<PropertyActualArg>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NamedCheckerPortConnectionAsterisk<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Symbol<'a>),
+pub struct NamedCheckerPortConnectionAsterisk {
+    pub nodes: (Vec<AttributeInstance>, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/instantiations/generated_instantiation.rs b/src/parser/instantiations/generated_instantiation.rs
index 88d07a8..6ce773d 100644
--- a/src/parser/instantiations/generated_instantiation.rs
+++ b/src/parser/instantiations/generated_instantiation.rs
@@ -9,138 +9,138 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct GenerateRegion<'a> {
-    pub nodes: (Keyword<'a>, Vec<GenerateItem<'a>>, Keyword<'a>),
+pub struct GenerateRegion {
+    pub nodes: (Keyword, Vec<GenerateItem>, Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct LoopGenerateConstruct<'a> {
+pub struct LoopGenerateConstruct {
     pub nodes: (
-        Keyword<'a>,
+        Keyword,
         Paren<
-            'a,
+            
             (
-                GenvarInitialization<'a>,
-                Symbol<'a>,
-                GenvarExpression<'a>,
-                Symbol<'a>,
-                GenvarIteration<'a>,
+                GenvarInitialization,
+                Symbol,
+                GenvarExpression,
+                Symbol,
+                GenvarIteration,
             ),
         >,
-        GenerateBlock<'a>,
+        GenerateBlock,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarInitialization<'a> {
+pub struct GenvarInitialization {
     pub nodes: (
-        Option<Genvar<'a>>,
-        GenvarIdentifier<'a>,
-        Symbol<'a>,
-        ConstantExpression<'a>,
+        Option<Genvar>,
+        GenvarIdentifier,
+        Symbol,
+        ConstantExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Genvar<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Genvar {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub enum GenvarIteration<'a> {
-    Assignment(GenvarIterationAssignment<'a>),
-    Prefix(GenvarIterationPrefix<'a>),
-    Suffix(GenvarIterationSuffix<'a>),
+pub enum GenvarIteration {
+    Assignment(GenvarIterationAssignment),
+    Prefix(GenvarIterationPrefix),
+    Suffix(GenvarIterationSuffix),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarIterationAssignment<'a> {
+pub struct GenvarIterationAssignment {
     pub nodes: (
-        GenvarIdentifier<'a>,
-        AssignmentOperator<'a>,
-        GenvarExpression<'a>,
+        GenvarIdentifier,
+        AssignmentOperator,
+        GenvarExpression,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarIterationPrefix<'a> {
-    pub nodes: (IncOrDecOperator<'a>, GenvarIdentifier<'a>),
+pub struct GenvarIterationPrefix {
+    pub nodes: (IncOrDecOperator, GenvarIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct GenvarIterationSuffix<'a> {
-    pub nodes: (GenvarIdentifier<'a>, IncOrDecOperator<'a>),
+pub struct GenvarIterationSuffix {
+    pub nodes: (GenvarIdentifier, IncOrDecOperator),
 }
 
 #[derive(Debug, Node)]
-pub enum ConditionalGenerateConstruct<'a> {
-    If(IfGenerateConstruct<'a>),
-    Case(CaseGenerateConstruct<'a>),
+pub enum ConditionalGenerateConstruct {
+    If(IfGenerateConstruct),
+    Case(CaseGenerateConstruct),
 }
 
 #[derive(Debug, Node)]
-pub struct IfGenerateConstruct<'a> {
+pub struct IfGenerateConstruct {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ConstantExpression<'a>>,
-        GenerateBlock<'a>,
-        Option<(Keyword<'a>, GenerateBlock<'a>)>,
+        Keyword,
+        Paren< ConstantExpression>,
+        GenerateBlock,
+        Option<(Keyword, GenerateBlock)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseGenerateConstruct<'a> {
+pub struct CaseGenerateConstruct {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ConstantExpression<'a>>,
-        Vec<CaseGenerateItem<'a>>,
-        Keyword<'a>,
+        Keyword,
+        Paren< ConstantExpression>,
+        Vec<CaseGenerateItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CaseGenerateItem<'a> {
-    Nondefault(CaseGenerateItemNondefault<'a>),
-    Default(CaseGenerateItemDefault<'a>),
+pub enum CaseGenerateItem {
+    Nondefault(CaseGenerateItemNondefault),
+    Default(CaseGenerateItemDefault),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseGenerateItemNondefault<'a> {
+pub struct CaseGenerateItemNondefault {
     pub nodes: (
-        List<Symbol<'a>, ConstantExpression<'a>>,
-        Symbol<'a>,
-        GenerateBlock<'a>,
+        List<Symbol, ConstantExpression>,
+        Symbol,
+        GenerateBlock,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CaseGenerateItemDefault<'a> {
-    pub nodes: (Keyword<'a>, Option<Symbol<'a>>, GenerateBlock<'a>),
+pub struct CaseGenerateItemDefault {
+    pub nodes: (Keyword, Option<Symbol>, GenerateBlock),
 }
 
 #[derive(Debug, Node)]
-pub enum GenerateBlock<'a> {
-    GenerateItem(GenerateItem<'a>),
-    Multiple(GenerateBlockMultiple<'a>),
+pub enum GenerateBlock {
+    GenerateItem(GenerateItem),
+    Multiple(GenerateBlockMultiple),
 }
 
 #[derive(Debug, Node)]
-pub struct GenerateBlockMultiple<'a> {
+pub struct GenerateBlockMultiple {
     pub nodes: (
-        Option<(GenerateBlockIdentifier<'a>, Symbol<'a>)>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, GenerateBlockIdentifier<'a>)>,
-        Vec<GenerateItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, GenerateBlockIdentifier<'a>)>,
+        Option<(GenerateBlockIdentifier, Symbol)>,
+        Keyword,
+        Option<(Symbol, GenerateBlockIdentifier)>,
+        Vec<GenerateItem>,
+        Keyword,
+        Option<(Symbol, GenerateBlockIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum GenerateItem<'a> {
-    ModuleOrGenerateItem(ModuleOrGenerateItem<'a>),
-    InterfaceOrGenerateItem(InterfaceOrGenerateItem<'a>),
-    CheckerOrGenerateItem(CheckerOrGenerateItem<'a>),
+pub enum GenerateItem {
+    ModuleOrGenerateItem(ModuleOrGenerateItem),
+    InterfaceOrGenerateItem(InterfaceOrGenerateItem),
+    CheckerOrGenerateItem(CheckerOrGenerateItem),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/instantiations/interface_instantiation.rs b/src/parser/instantiations/interface_instantiation.rs
index f3e4840..91053c4 100644
--- a/src/parser/instantiations/interface_instantiation.rs
+++ b/src/parser/instantiations/interface_instantiation.rs
@@ -6,12 +6,12 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct InterfaceInstantiation<'a> {
+pub struct InterfaceInstantiation {
     pub nodes: (
-        InterfaceIdentifier<'a>,
-        Option<ParameterValueAssignment<'a>>,
-        List<Symbol<'a>, HierarchicalInstance<'a>>,
-        Symbol<'a>,
+        InterfaceIdentifier,
+        Option<ParameterValueAssignment>,
+        List<Symbol, HierarchicalInstance>,
+        Symbol,
     ),
 }
 
diff --git a/src/parser/instantiations/module_instantiation.rs b/src/parser/instantiations/module_instantiation.rs
index 9194ede..dae0400 100644
--- a/src/parser/instantiations/module_instantiation.rs
+++ b/src/parser/instantiations/module_instantiation.rs
@@ -8,106 +8,106 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ModuleInstantiation<'a> {
+pub struct ModuleInstantiation {
     pub nodes: (
-        ModuleIdentifier<'a>,
-        Option<ParameterValueAssignment<'a>>,
-        List<Symbol<'a>, HierarchicalInstance<'a>>,
-        Symbol<'a>,
+        ModuleIdentifier,
+        Option<ParameterValueAssignment>,
+        List<Symbol, HierarchicalInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterValueAssignment<'a> {
+pub struct ParameterValueAssignment {
     pub nodes: (
-        Symbol<'a>,
-        Paren<'a, Option<ListOfParameterAssignments<'a>>>,
+        Symbol,
+        Paren< Option<ListOfParameterAssignments>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ListOfParameterAssignments<'a> {
-    Ordered(ListOfParameterAssignmentsOrdered<'a>),
-    Named(ListOfParameterAssignmentsNamed<'a>),
+pub enum ListOfParameterAssignments {
+    Ordered(ListOfParameterAssignmentsOrdered),
+    Named(ListOfParameterAssignmentsNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfParameterAssignmentsOrdered<'a> {
-    pub nodes: (List<Symbol<'a>, OrderedParameterAssignment<'a>>,),
+pub struct ListOfParameterAssignmentsOrdered {
+    pub nodes: (List<Symbol, OrderedParameterAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfParameterAssignmentsNamed<'a> {
-    pub nodes: (List<Symbol<'a>, NamedParameterAssignment<'a>>,),
+pub struct ListOfParameterAssignmentsNamed {
+    pub nodes: (List<Symbol, NamedParameterAssignment>,),
 }
 
 #[derive(Debug, Node)]
-pub struct OrderedParameterAssignment<'a> {
-    pub nodes: (ParamExpression<'a>,),
+pub struct OrderedParameterAssignment {
+    pub nodes: (ParamExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct NamedParameterAssignment<'a> {
+pub struct NamedParameterAssignment {
     pub nodes: (
-        Symbol<'a>,
-        ParameterIdentifier<'a>,
-        Paren<'a, Option<ParamExpression<'a>>>,
+        Symbol,
+        ParameterIdentifier,
+        Paren< Option<ParamExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct HierarchicalInstance<'a> {
+pub struct HierarchicalInstance {
     pub nodes: (
-        NameOfInstance<'a>,
-        Paren<'a, Option<ListOfPortConnections<'a>>>,
+        NameOfInstance,
+        Paren< Option<ListOfPortConnections>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NameOfInstance<'a> {
-    pub nodes: (InstanceIdentifier<'a>, Vec<UnpackedDimension<'a>>),
+pub struct NameOfInstance {
+    pub nodes: (InstanceIdentifier, Vec<UnpackedDimension>),
 }
 
 #[derive(Debug, Node)]
-pub enum ListOfPortConnections<'a> {
-    Ordered(ListOfPortConnectionsOrdered<'a>),
-    Named(ListOfPortConnectionsNamed<'a>),
+pub enum ListOfPortConnections {
+    Ordered(ListOfPortConnectionsOrdered),
+    Named(ListOfPortConnectionsNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPortConnectionsOrdered<'a> {
-    pub nodes: (List<Symbol<'a>, OrderedPortConnection<'a>>,),
+pub struct ListOfPortConnectionsOrdered {
+    pub nodes: (List<Symbol, OrderedPortConnection>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPortConnectionsNamed<'a> {
-    pub nodes: (List<Symbol<'a>, NamedPortConnection<'a>>,),
+pub struct ListOfPortConnectionsNamed {
+    pub nodes: (List<Symbol, NamedPortConnection>,),
 }
 
 #[derive(Debug, Node)]
-pub struct OrderedPortConnection<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Option<Expression<'a>>),
+pub struct OrderedPortConnection {
+    pub nodes: (Vec<AttributeInstance>, Option<Expression>),
 }
 
 #[derive(Debug, Node)]
-pub enum NamedPortConnection<'a> {
-    Identifier(NamedPortConnectionIdentifier<'a>),
-    Asterisk(NamedPortConnectionAsterisk<'a>),
+pub enum NamedPortConnection {
+    Identifier(NamedPortConnectionIdentifier),
+    Asterisk(NamedPortConnectionAsterisk),
 }
 
 #[derive(Debug, Node)]
-pub struct NamedPortConnectionIdentifier<'a> {
+pub struct NamedPortConnectionIdentifier {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Symbol<'a>,
-        PortIdentifier<'a>,
-        Option<Paren<'a, Option<Expression<'a>>>>,
+        Vec<AttributeInstance>,
+        Symbol,
+        PortIdentifier,
+        Option<Paren< Option<Expression>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NamedPortConnectionAsterisk<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Symbol<'a>),
+pub struct NamedPortConnectionAsterisk {
+    pub nodes: (Vec<AttributeInstance>, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/instantiations/program_instantiation.rs b/src/parser/instantiations/program_instantiation.rs
index bf89859..b041757 100644
--- a/src/parser/instantiations/program_instantiation.rs
+++ b/src/parser/instantiations/program_instantiation.rs
@@ -6,12 +6,12 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ProgramInstantiation<'a> {
+pub struct ProgramInstantiation {
     pub nodes: (
-        ProgramIdentifier<'a>,
-        Option<ParameterValueAssignment<'a>>,
-        List<Symbol<'a>, HierarchicalInstance<'a>>,
-        Symbol<'a>,
+        ProgramIdentifier,
+        Option<ParameterValueAssignment>,
+        List<Symbol, HierarchicalInstance>,
+        Symbol,
     ),
 }
 
diff --git a/src/parser/primitive_instances/primitive_gate_and_switch_types.rs b/src/parser/primitive_instances/primitive_gate_and_switch_types.rs
index 9a0ceb0..cf48c49 100644
--- a/src/parser/primitive_instances/primitive_gate_and_switch_types.rs
+++ b/src/parser/primitive_instances/primitive_gate_and_switch_types.rs
@@ -6,38 +6,38 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct CmosSwitchtype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct CmosSwitchtype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct EnableGatetype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct EnableGatetype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct MosSwitchtype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct MosSwitchtype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct NInputGatetype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct NInputGatetype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct NOutputGatetype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct NOutputGatetype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct PassEnSwitchtype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct PassEnSwitchtype {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct PassSwitchtype<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct PassSwitchtype {
+    pub nodes: (Keyword,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/primitive_instances/primitive_instantiation_and_instances.rs b/src/parser/primitive_instances/primitive_instantiation_and_instances.rs
index 9c484e9..f41fd67 100644
--- a/src/parser/primitive_instances/primitive_instantiation_and_instances.rs
+++ b/src/parser/primitive_instances/primitive_instantiation_and_instances.rs
@@ -8,221 +8,221 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum GateInstantiation<'a> {
-    Cmos(GateInstantiationCmos<'a>),
-    Enable(GateInstantiationEnable<'a>),
-    Mos(GateInstantiationMos<'a>),
-    NInput(GateInstantiationNInput<'a>),
-    NOutput(GateInstantiationNOutput<'a>),
-    PassEn(GateInstantiationPassEn<'a>),
-    Pass(GateInstantiationPass<'a>),
-    Pulldown(GateInstantiationPulldown<'a>),
-    Pullup(GateInstantiationPullup<'a>),
+pub enum GateInstantiation {
+    Cmos(GateInstantiationCmos),
+    Enable(GateInstantiationEnable),
+    Mos(GateInstantiationMos),
+    NInput(GateInstantiationNInput),
+    NOutput(GateInstantiationNOutput),
+    PassEn(GateInstantiationPassEn),
+    Pass(GateInstantiationPass),
+    Pulldown(GateInstantiationPulldown),
+    Pullup(GateInstantiationPullup),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationCmos<'a> {
+pub struct GateInstantiationCmos {
     pub nodes: (
-        CmosSwitchtype<'a>,
-        Option<Delay3<'a>>,
-        List<Symbol<'a>, CmosSwitchInstance<'a>>,
-        Symbol<'a>,
+        CmosSwitchtype,
+        Option<Delay3>,
+        List<Symbol, CmosSwitchInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationEnable<'a> {
+pub struct GateInstantiationEnable {
     pub nodes: (
-        EnableGatetype<'a>,
-        Option<DriveStrength<'a>>,
-        Option<Delay3<'a>>,
-        List<Symbol<'a>, EnableGateInstance<'a>>,
-        Symbol<'a>,
+        EnableGatetype,
+        Option<DriveStrength>,
+        Option<Delay3>,
+        List<Symbol, EnableGateInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationMos<'a> {
+pub struct GateInstantiationMos {
     pub nodes: (
-        MosSwitchtype<'a>,
-        Option<Delay3<'a>>,
-        List<Symbol<'a>, MosSwitchInstance<'a>>,
-        Symbol<'a>,
+        MosSwitchtype,
+        Option<Delay3>,
+        List<Symbol, MosSwitchInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationNInput<'a> {
+pub struct GateInstantiationNInput {
     pub nodes: (
-        NInputGatetype<'a>,
-        Option<DriveStrength<'a>>,
-        Option<Delay2<'a>>,
-        List<Symbol<'a>, NInputGateInstance<'a>>,
-        Symbol<'a>,
+        NInputGatetype,
+        Option<DriveStrength>,
+        Option<Delay2>,
+        List<Symbol, NInputGateInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationNOutput<'a> {
+pub struct GateInstantiationNOutput {
     pub nodes: (
-        NOutputGatetype<'a>,
-        Option<DriveStrength<'a>>,
-        Option<Delay2<'a>>,
-        List<Symbol<'a>, NOutputGateInstance<'a>>,
-        Symbol<'a>,
+        NOutputGatetype,
+        Option<DriveStrength>,
+        Option<Delay2>,
+        List<Symbol, NOutputGateInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationPassEn<'a> {
+pub struct GateInstantiationPassEn {
     pub nodes: (
-        PassEnSwitchtype<'a>,
-        Option<Delay2<'a>>,
-        List<Symbol<'a>, PassEnableSwitchInstance<'a>>,
-        Symbol<'a>,
+        PassEnSwitchtype,
+        Option<Delay2>,
+        List<Symbol, PassEnableSwitchInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationPass<'a> {
+pub struct GateInstantiationPass {
     pub nodes: (
-        PassSwitchtype<'a>,
-        List<Symbol<'a>, PassSwitchInstance<'a>>,
-        Symbol<'a>,
+        PassSwitchtype,
+        List<Symbol, PassSwitchInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationPulldown<'a> {
+pub struct GateInstantiationPulldown {
     pub nodes: (
-        Keyword<'a>,
-        Option<PulldownStrength<'a>>,
-        List<Symbol<'a>, PullGateInstance<'a>>,
-        Symbol<'a>,
+        Keyword,
+        Option<PulldownStrength>,
+        List<Symbol, PullGateInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct GateInstantiationPullup<'a> {
+pub struct GateInstantiationPullup {
     pub nodes: (
-        Keyword<'a>,
-        Option<PullupStrength<'a>>,
-        List<Symbol<'a>, PullGateInstance<'a>>,
-        Symbol<'a>,
+        Keyword,
+        Option<PullupStrength>,
+        List<Symbol, PullGateInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CmosSwitchInstance<'a> {
+pub struct CmosSwitchInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                OutputTerminal<'a>,
-                Symbol<'a>,
-                InputTerminal<'a>,
-                Symbol<'a>,
-                NcontrolTerminal<'a>,
-                Symbol<'a>,
-                PcontrolTerminal<'a>,
+                OutputTerminal,
+                Symbol,
+                InputTerminal,
+                Symbol,
+                NcontrolTerminal,
+                Symbol,
+                PcontrolTerminal,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct EnableGateInstance<'a> {
+pub struct EnableGateInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                OutputTerminal<'a>,
-                Symbol<'a>,
-                InputTerminal<'a>,
-                Symbol<'a>,
-                EnableTerminal<'a>,
+                OutputTerminal,
+                Symbol,
+                InputTerminal,
+                Symbol,
+                EnableTerminal,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct MosSwitchInstance<'a> {
+pub struct MosSwitchInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                OutputTerminal<'a>,
-                Symbol<'a>,
-                InputTerminal<'a>,
-                Symbol<'a>,
-                EnableTerminal<'a>,
+                OutputTerminal,
+                Symbol,
+                InputTerminal,
+                Symbol,
+                EnableTerminal,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NInputGateInstance<'a> {
+pub struct NInputGateInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                OutputTerminal<'a>,
-                Symbol<'a>,
-                List<Symbol<'a>, InputTerminal<'a>>,
+                OutputTerminal,
+                Symbol,
+                List<Symbol, InputTerminal>,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NOutputGateInstance<'a> {
+pub struct NOutputGateInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                List<Symbol<'a>, OutputTerminal<'a>>,
-                Symbol<'a>,
-                InputTerminal<'a>,
+                List<Symbol, OutputTerminal>,
+                Symbol,
+                InputTerminal,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PassSwitchInstance<'a> {
+pub struct PassSwitchInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
-        Paren<'a, (InoutTerminal<'a>, Symbol<'a>, InoutTerminal<'a>)>,
+        Option<NameOfInstance>,
+        Paren< (InoutTerminal, Symbol, InoutTerminal)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PassEnableSwitchInstance<'a> {
+pub struct PassEnableSwitchInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
+        Option<NameOfInstance>,
         Paren<
-            'a,
+            
             (
-                InoutTerminal<'a>,
-                Symbol<'a>,
-                InoutTerminal<'a>,
-                Symbol<'a>,
-                EnableTerminal<'a>,
+                InoutTerminal,
+                Symbol,
+                InoutTerminal,
+                Symbol,
+                EnableTerminal,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PullGateInstance<'a> {
-    pub nodes: (Option<NameOfInstance<'a>>, Paren<'a, OutputTerminal<'a>>),
+pub struct PullGateInstance {
+    pub nodes: (Option<NameOfInstance>, Paren< OutputTerminal>),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/primitive_instances/primitive_strengths.rs b/src/parser/primitive_instances/primitive_strengths.rs
index 61ba61e..5788a5a 100644
--- a/src/parser/primitive_instances/primitive_strengths.rs
+++ b/src/parser/primitive_instances/primitive_strengths.rs
@@ -6,47 +6,47 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum PulldownStrength<'a> {
-    Strength01(PulldownStrength01<'a>),
-    Strength10(PulldownStrength10<'a>),
-    Strength0(PulldownStrength0<'a>),
+pub enum PulldownStrength {
+    Strength01(PulldownStrength01),
+    Strength10(PulldownStrength10),
+    Strength0(PulldownStrength0),
 }
 
 #[derive(Debug, Node)]
-pub struct PulldownStrength01<'a> {
-    pub nodes: (Paren<'a, (Strength0<'a>, Symbol<'a>, Strength1<'a>)>,),
+pub struct PulldownStrength01 {
+    pub nodes: (Paren< (Strength0, Symbol, Strength1)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PulldownStrength10<'a> {
-    pub nodes: (Paren<'a, (Strength1<'a>, Symbol<'a>, Strength0<'a>)>,),
+pub struct PulldownStrength10 {
+    pub nodes: (Paren< (Strength1, Symbol, Strength0)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PulldownStrength0<'a> {
-    pub nodes: (Paren<'a, Strength0<'a>>,),
+pub struct PulldownStrength0 {
+    pub nodes: (Paren< Strength0>,),
 }
 
 #[derive(Debug, Node)]
-pub enum PullupStrength<'a> {
-    Strength01(PullupStrength01<'a>),
-    Strength10(PullupStrength10<'a>),
-    Strength1(PullupStrength1<'a>),
+pub enum PullupStrength {
+    Strength01(PullupStrength01),
+    Strength10(PullupStrength10),
+    Strength1(PullupStrength1),
 }
 
 #[derive(Debug, Node)]
-pub struct PullupStrength01<'a> {
-    pub nodes: (Paren<'a, (Strength0<'a>, Symbol<'a>, Strength1<'a>)>,),
+pub struct PullupStrength01 {
+    pub nodes: (Paren< (Strength0, Symbol, Strength1)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PullupStrength10<'a> {
-    pub nodes: (Paren<'a, (Strength1<'a>, Symbol<'a>, Strength0<'a>)>,),
+pub struct PullupStrength10 {
+    pub nodes: (Paren< (Strength1, Symbol, Strength0)>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PullupStrength1<'a> {
-    pub nodes: (Paren<'a, Strength1<'a>>,),
+pub struct PullupStrength1 {
+    pub nodes: (Paren< Strength1>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/primitive_instances/primitive_terminals.rs b/src/parser/primitive_instances/primitive_terminals.rs
index e54cd50..1df3573 100644
--- a/src/parser/primitive_instances/primitive_terminals.rs
+++ b/src/parser/primitive_instances/primitive_terminals.rs
@@ -5,33 +5,33 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct EnableTerminal<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct EnableTerminal {
+    pub nodes: (Expression,),
 }
 
 #[derive(Debug, Node)]
-pub struct InoutTerminal<'a> {
-    pub nodes: (NetLvalue<'a>,),
+pub struct InoutTerminal {
+    pub nodes: (NetLvalue,),
 }
 
 #[derive(Debug, Node)]
-pub struct InputTerminal<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct InputTerminal {
+    pub nodes: (Expression,),
 }
 
 #[derive(Debug, Node)]
-pub struct NcontrolTerminal<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct NcontrolTerminal {
+    pub nodes: (Expression,),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputTerminal<'a> {
-    pub nodes: (NetLvalue<'a>,),
+pub struct OutputTerminal {
+    pub nodes: (NetLvalue,),
 }
 
 #[derive(Debug, Node)]
-pub struct PcontrolTerminal<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct PcontrolTerminal {
+    pub nodes: (Expression,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/checker_items.rs b/src/parser/source_text/checker_items.rs
index 3987673..9528873 100644
--- a/src/parser/source_text/checker_items.rs
+++ b/src/parser/source_text/checker_items.rs
@@ -9,85 +9,85 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct CheckerPortList<'a> {
-    pub nodes: (List<Symbol<'a>, CheckerPortItem<'a>>,),
+pub struct CheckerPortList {
+    pub nodes: (List<Symbol, CheckerPortItem>,),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerPortItem<'a> {
+pub struct CheckerPortItem {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Option<CheckerPortDirection<'a>>,
-        PropertyFormalType<'a>,
-        FormalPortIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, PropertyActualArg<'a>)>,
+        Vec<AttributeInstance>,
+        Option<CheckerPortDirection>,
+        PropertyFormalType,
+        FormalPortIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, PropertyActualArg)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CheckerPortDirection<'a> {
-    Input(Keyword<'a>),
-    Output(Keyword<'a>),
+pub enum CheckerPortDirection {
+    Input(Keyword),
+    Output(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum CheckerOrGenerateItem<'a> {
-    CheckerOrGenerateItemDeclaration(CheckerOrGenerateItemDeclaration<'a>),
-    InitialConstruct(InitialConstruct<'a>),
-    AlwaysConstruct(AlwaysConstruct<'a>),
-    FinalConstruct(FinalConstruct<'a>),
-    AssertionItem(AssertionItem<'a>),
-    ContinuousAssign(ContinuousAssign<'a>),
-    CheckerGenerateItem(CheckerGenerateItem<'a>),
+pub enum CheckerOrGenerateItem {
+    CheckerOrGenerateItemDeclaration(CheckerOrGenerateItemDeclaration),
+    InitialConstruct(InitialConstruct),
+    AlwaysConstruct(AlwaysConstruct),
+    FinalConstruct(FinalConstruct),
+    AssertionItem(AssertionItem),
+    ContinuousAssign(ContinuousAssign),
+    CheckerGenerateItem(CheckerGenerateItem),
 }
 
 #[derive(Debug, Node)]
-pub enum CheckerOrGenerateItemDeclaration<'a> {
-    Data(CheckerOrGenerateItemDeclarationData<'a>),
-    FunctionDeclaration(FunctionDeclaration<'a>),
-    CheckerDeclaration(CheckerDeclaration<'a>),
-    AssertionItemDeclaration(AssertionItemDeclaration<'a>),
-    CovergroupDeclaration(CovergroupDeclaration<'a>),
-    GenvarDeclaration(GenvarDeclaration<'a>),
-    ClockingDeclaration(ClockingDeclaration<'a>),
-    Clocking(CheckerOrGenerateItemDeclarationClocking<'a>),
-    Disable(CheckerOrGenerateItemDeclarationDisable<'a>),
-    Empty(Symbol<'a>),
+pub enum CheckerOrGenerateItemDeclaration {
+    Data(CheckerOrGenerateItemDeclarationData),
+    FunctionDeclaration(FunctionDeclaration),
+    CheckerDeclaration(CheckerDeclaration),
+    AssertionItemDeclaration(AssertionItemDeclaration),
+    CovergroupDeclaration(CovergroupDeclaration),
+    GenvarDeclaration(GenvarDeclaration),
+    ClockingDeclaration(ClockingDeclaration),
+    Clocking(CheckerOrGenerateItemDeclarationClocking),
+    Disable(CheckerOrGenerateItemDeclarationDisable),
+    Empty(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerOrGenerateItemDeclarationData<'a> {
-    pub nodes: (Option<Rand<'a>>, DataDeclaration<'a>),
+pub struct CheckerOrGenerateItemDeclarationData {
+    pub nodes: (Option<Rand>, DataDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct Rand<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Rand {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerOrGenerateItemDeclarationClocking<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, ClockingIdentifier<'a>, Symbol<'a>),
+pub struct CheckerOrGenerateItemDeclarationClocking {
+    pub nodes: (Keyword, Keyword, ClockingIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerOrGenerateItemDeclarationDisable<'a> {
+pub struct CheckerOrGenerateItemDeclarationDisable {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Keyword<'a>,
-        ExpressionOrDist<'a>,
-        Symbol<'a>,
+        Keyword,
+        Keyword,
+        Keyword,
+        ExpressionOrDist,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum CheckerGenerateItem<'a> {
-    LoopGenerateConstruct(Box<LoopGenerateConstruct<'a>>),
-    ConditionalGenerateConstruct(Box<ConditionalGenerateConstruct<'a>>),
-    GenerateRegion(GenerateRegion<'a>),
-    ElaborationSystemTask(ElaborationSystemTask<'a>),
+pub enum CheckerGenerateItem {
+    LoopGenerateConstruct(Box<LoopGenerateConstruct>),
+    ConditionalGenerateConstruct(Box<ConditionalGenerateConstruct>),
+    GenerateRegion(GenerateRegion),
+    ElaborationSystemTask(ElaborationSystemTask),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/class_items.rs b/src/parser/source_text/class_items.rs
index f19e8e5..19ed8ae 100644
--- a/src/parser/source_text/class_items.rs
+++ b/src/parser/source_text/class_items.rs
@@ -9,193 +9,193 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ClassItem<'a> {
-    Property(ClassItemProperty<'a>),
-    Method(ClassItemMethod<'a>),
-    Constraint(ClassItemConstraint<'a>),
-    Declaration(ClassItemDeclaration<'a>),
-    Covergroup(ClassItemCovergroup<'a>),
-    LocalParameterDeclaration((LocalParameterDeclaration<'a>, Symbol<'a>)),
-    ParameterDeclaration((ParameterDeclaration<'a>, Symbol<'a>)),
-    Empty(Symbol<'a>),
+pub enum ClassItem {
+    Property(ClassItemProperty),
+    Method(ClassItemMethod),
+    Constraint(ClassItemConstraint),
+    Declaration(ClassItemDeclaration),
+    Covergroup(ClassItemCovergroup),
+    LocalParameterDeclaration((LocalParameterDeclaration, Symbol)),
+    ParameterDeclaration((ParameterDeclaration, Symbol)),
+    Empty(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassItemProperty<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ClassProperty<'a>),
+pub struct ClassItemProperty {
+    pub nodes: (Vec<AttributeInstance>, ClassProperty),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassItemMethod<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ClassMethod<'a>),
+pub struct ClassItemMethod {
+    pub nodes: (Vec<AttributeInstance>, ClassMethod),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassItemConstraint<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ClassConstraint<'a>),
+pub struct ClassItemConstraint {
+    pub nodes: (Vec<AttributeInstance>, ClassConstraint),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassItemDeclaration<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ClassDeclaration<'a>),
+pub struct ClassItemDeclaration {
+    pub nodes: (Vec<AttributeInstance>, ClassDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassItemCovergroup<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, CovergroupDeclaration<'a>),
+pub struct ClassItemCovergroup {
+    pub nodes: (Vec<AttributeInstance>, CovergroupDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassProperty<'a> {
-    NonConst(ClassPropertyNonConst<'a>),
-    Const(ClassPropertyConst<'a>),
+pub enum ClassProperty {
+    NonConst(ClassPropertyNonConst),
+    Const(ClassPropertyConst),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassPropertyNonConst<'a> {
-    pub nodes: (Vec<PropertyQualifier<'a>>, DataDeclaration<'a>),
+pub struct ClassPropertyNonConst {
+    pub nodes: (Vec<PropertyQualifier>, DataDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassPropertyConst<'a> {
+pub struct ClassPropertyConst {
     pub nodes: (
-        Keyword<'a>,
-        Vec<ClassItemQualifier<'a>>,
-        DataType<'a>,
-        ConstIdentifier<'a>,
-        Option<(Symbol<'a>, ConstantExpression<'a>)>,
-        Symbol<'a>,
+        Keyword,
+        Vec<ClassItemQualifier>,
+        DataType,
+        ConstIdentifier,
+        Option<(Symbol, ConstantExpression)>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassMethod<'a> {
-    Task(ClassMethodTask<'a>),
-    Function(ClassMethodFunction<'a>),
-    PureVirtual(ClassMethodPureVirtual<'a>),
-    ExternMethod(ClassMethodExternMethod<'a>),
-    Constructor(ClassMethodConstructor<'a>),
-    ExternConstructor(ClassMethodExternConstructor<'a>),
+pub enum ClassMethod {
+    Task(ClassMethodTask),
+    Function(ClassMethodFunction),
+    PureVirtual(ClassMethodPureVirtual),
+    ExternMethod(ClassMethodExternMethod),
+    Constructor(ClassMethodConstructor),
+    ExternConstructor(ClassMethodExternConstructor),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodTask<'a> {
-    pub nodes: (Vec<MethodQualifier<'a>>, TaskDeclaration<'a>),
+pub struct ClassMethodTask {
+    pub nodes: (Vec<MethodQualifier>, TaskDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodFunction<'a> {
-    pub nodes: (Vec<MethodQualifier<'a>>, FunctionDeclaration<'a>),
+pub struct ClassMethodFunction {
+    pub nodes: (Vec<MethodQualifier>, FunctionDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodPureVirtual<'a> {
+pub struct ClassMethodPureVirtual {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Vec<ClassItemQualifier<'a>>,
-        MethodPrototype<'a>,
-        Symbol<'a>,
+        Keyword,
+        Keyword,
+        Vec<ClassItemQualifier>,
+        MethodPrototype,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodExternMethod<'a> {
+pub struct ClassMethodExternMethod {
     pub nodes: (
-        Keyword<'a>,
-        Vec<MethodQualifier<'a>>,
-        MethodPrototype<'a>,
-        Symbol<'a>,
+        Keyword,
+        Vec<MethodQualifier>,
+        MethodPrototype,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodConstructor<'a> {
-    pub nodes: (Vec<MethodQualifier<'a>>, ClassConstructorDeclaration<'a>),
+pub struct ClassMethodConstructor {
+    pub nodes: (Vec<MethodQualifier>, ClassConstructorDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassMethodExternConstructor<'a> {
+pub struct ClassMethodExternConstructor {
     pub nodes: (
-        Keyword<'a>,
-        Vec<MethodQualifier<'a>>,
-        ClassConstructorPrototype<'a>,
+        Keyword,
+        Vec<MethodQualifier>,
+        ClassConstructorPrototype,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassConstructorPrototype<'a> {
+pub struct ClassConstructorPrototype {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Option<Paren<'a, Option<TfPortList<'a>>>>,
-        Symbol<'a>,
+        Keyword,
+        Keyword,
+        Option<Paren< Option<TfPortList>>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassConstraint<'a> {
-    ConstraintPrototype(ConstraintPrototype<'a>),
-    ConstraintDeclaration(ConstraintDeclaration<'a>),
+pub enum ClassConstraint {
+    ConstraintPrototype(ConstraintPrototype),
+    ConstraintDeclaration(ConstraintDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum ClassItemQualifier<'a> {
-    Static(Keyword<'a>),
-    Protected(Keyword<'a>),
-    Local(Keyword<'a>),
+pub enum ClassItemQualifier {
+    Static(Keyword),
+    Protected(Keyword),
+    Local(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum PropertyQualifier<'a> {
-    RandomQualifier(RandomQualifier<'a>),
-    ClassItemQualifier(ClassItemQualifier<'a>),
+pub enum PropertyQualifier {
+    RandomQualifier(RandomQualifier),
+    ClassItemQualifier(ClassItemQualifier),
 }
 
 #[derive(Debug, Node)]
-pub enum RandomQualifier<'a> {
-    Rand(Keyword<'a>),
-    Randc(Keyword<'a>),
+pub enum RandomQualifier {
+    Rand(Keyword),
+    Randc(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum MethodQualifier<'a> {
-    Virtual(Keyword<'a>),
-    PureVirtual((Keyword<'a>, Keyword<'a>)),
-    ClassItemQualifier(ClassItemQualifier<'a>),
+pub enum MethodQualifier {
+    Virtual(Keyword),
+    PureVirtual((Keyword, Keyword)),
+    ClassItemQualifier(ClassItemQualifier),
 }
 
 #[derive(Debug, Node)]
-pub enum MethodPrototype<'a> {
-    TaskPrototype(TaskPrototype<'a>),
-    FunctionPrototype(FunctionPrototype<'a>),
+pub enum MethodPrototype {
+    TaskPrototype(TaskPrototype),
+    FunctionPrototype(FunctionPrototype),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassConstructorDeclaration<'a> {
+pub struct ClassConstructorDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Option<ClassScope<'a>>,
-        Keyword<'a>,
-        Option<Paren<'a, Option<TfPortList<'a>>>>,
-        Symbol<'a>,
-        Vec<BlockItemDeclaration<'a>>,
+        Keyword,
+        Option<ClassScope>,
+        Keyword,
+        Option<Paren< Option<TfPortList>>>,
+        Symbol,
+        Vec<BlockItemDeclaration>,
         Option<(
-            Keyword<'a>,
-            Symbol<'a>,
-            Keyword<'a>,
-            Option<Paren<'a, ListOfArguments<'a>>>,
-            Symbol<'a>,
+            Keyword,
+            Symbol,
+            Keyword,
+            Option<Paren< ListOfArguments>>,
+            Symbol,
         )>,
-        Vec<FunctionStatementOrNull<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, New<'a>)>,
+        Vec<FunctionStatementOrNull>,
+        Keyword,
+        Option<(Symbol, New)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct New<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct New {
+    pub nodes: (Keyword,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/configuration_source_text.rs b/src/parser/source_text/configuration_source_text.rs
index 7847f92..5da92f2 100644
--- a/src/parser/source_text/configuration_source_text.rs
+++ b/src/parser/source_text/configuration_source_text.rs
@@ -9,137 +9,137 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ConfigDeclaration<'a> {
+pub struct ConfigDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        ConfigIdentifier<'a>,
-        Symbol<'a>,
-        Vec<(LocalParameterDeclaration<'a>, Symbol<'a>)>,
-        DesignStatement<'a>,
-        Vec<ConfigRuleStatement<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ConfigIdentifier<'a>)>,
+        Keyword,
+        ConfigIdentifier,
+        Symbol,
+        Vec<(LocalParameterDeclaration, Symbol)>,
+        DesignStatement,
+        Vec<ConfigRuleStatement>,
+        Keyword,
+        Option<(Symbol, ConfigIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct DesignStatement<'a> {
+pub struct DesignStatement {
     pub nodes: (
-        Keyword<'a>,
+        Keyword,
         Vec<(
-            Option<(LibraryIdentifier<'a>, Symbol<'a>)>,
-            CellIdentifier<'a>,
+            Option<(LibraryIdentifier, Symbol)>,
+            CellIdentifier,
         )>,
-        Symbol<'a>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConfigRuleStatement<'a> {
-    Default(ConfigRuleStatementDefault<'a>),
-    InstLib(ConfigRuleStatementInstLib<'a>),
-    InstUse(ConfigRuleStatementInstUse<'a>),
-    CellLib(ConfigRuleStatementCellLib<'a>),
-    CellUse(ConfigRuleStatementCellUse<'a>),
+pub enum ConfigRuleStatement {
+    Default(ConfigRuleStatementDefault),
+    InstLib(ConfigRuleStatementInstLib),
+    InstUse(ConfigRuleStatementInstUse),
+    CellLib(ConfigRuleStatementCellLib),
+    CellUse(ConfigRuleStatementCellUse),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigRuleStatementDefault<'a> {
-    pub nodes: (DefaultClause<'a>, LiblistClause<'a>, Symbol<'a>),
+pub struct ConfigRuleStatementDefault {
+    pub nodes: (DefaultClause, LiblistClause, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigRuleStatementInstLib<'a> {
-    pub nodes: (InstClause<'a>, LiblistClause<'a>, Symbol<'a>),
+pub struct ConfigRuleStatementInstLib {
+    pub nodes: (InstClause, LiblistClause, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigRuleStatementInstUse<'a> {
-    pub nodes: (InstClause<'a>, UseClause<'a>, Symbol<'a>),
+pub struct ConfigRuleStatementInstUse {
+    pub nodes: (InstClause, UseClause, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigRuleStatementCellLib<'a> {
-    pub nodes: (CellClause<'a>, LiblistClause<'a>, Symbol<'a>),
+pub struct ConfigRuleStatementCellLib {
+    pub nodes: (CellClause, LiblistClause, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ConfigRuleStatementCellUse<'a> {
-    pub nodes: (CellClause<'a>, UseClause<'a>, Symbol<'a>),
+pub struct ConfigRuleStatementCellUse {
+    pub nodes: (CellClause, UseClause, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct DefaultClause<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct DefaultClause {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct InstClause<'a> {
-    pub nodes: (Keyword<'a>, InstName<'a>),
+pub struct InstClause {
+    pub nodes: (Keyword, InstName),
 }
 
 #[derive(Debug, Node)]
-pub struct InstName<'a> {
+pub struct InstName {
     pub nodes: (
-        TopmoduleIdentifier<'a>,
-        Vec<(Symbol<'a>, InstanceIdentifier<'a>)>,
+        TopmoduleIdentifier,
+        Vec<(Symbol, InstanceIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CellClause<'a> {
+pub struct CellClause {
     pub nodes: (
-        Keyword<'a>,
-        Option<(LibraryIdentifier<'a>, Symbol<'a>)>,
-        CellIdentifier<'a>,
+        Keyword,
+        Option<(LibraryIdentifier, Symbol)>,
+        CellIdentifier,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct LiblistClause<'a> {
-    pub nodes: (Keyword<'a>, Vec<LibraryIdentifier<'a>>),
+pub struct LiblistClause {
+    pub nodes: (Keyword, Vec<LibraryIdentifier>),
 }
 
 #[derive(Debug, Node)]
-pub enum UseClause<'a> {
-    Cell(UseClauseCell<'a>),
-    Named(UseClauseNamed<'a>),
-    CellNamed(UseClauseCellNamed<'a>),
+pub enum UseClause {
+    Cell(UseClauseCell),
+    Named(UseClauseNamed),
+    CellNamed(UseClauseCellNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct UseClauseCell<'a> {
+pub struct UseClauseCell {
     pub nodes: (
-        Keyword<'a>,
-        Option<(LibraryIdentifier<'a>, Symbol<'a>)>,
-        CellIdentifier<'a>,
-        Option<(Symbol<'a>, Config<'a>)>,
+        Keyword,
+        Option<(LibraryIdentifier, Symbol)>,
+        CellIdentifier,
+        Option<(Symbol, Config)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UseClauseNamed<'a> {
+pub struct UseClauseNamed {
     pub nodes: (
-        Keyword<'a>,
-        List<Symbol<'a>, NamedParameterAssignment<'a>>,
-        Option<(Symbol<'a>, Config<'a>)>,
+        Keyword,
+        List<Symbol, NamedParameterAssignment>,
+        Option<(Symbol, Config)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UseClauseCellNamed<'a> {
+pub struct UseClauseCellNamed {
     pub nodes: (
-        Keyword<'a>,
-        Option<(LibraryIdentifier<'a>, Symbol<'a>)>,
-        CellIdentifier<'a>,
-        List<Symbol<'a>, NamedParameterAssignment<'a>>,
-        Option<(Symbol<'a>, Config<'a>)>,
+        Keyword,
+        Option<(LibraryIdentifier, Symbol)>,
+        CellIdentifier,
+        List<Symbol, NamedParameterAssignment>,
+        Option<(Symbol, Config)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Config<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Config {
+    pub nodes: (Keyword,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/constraints.rs b/src/parser/source_text/constraints.rs
index b8c621d..7fc80a1 100644
--- a/src/parser/source_text/constraints.rs
+++ b/src/parser/source_text/constraints.rs
@@ -9,184 +9,184 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct ConstraintDeclaration<'a> {
+pub struct ConstraintDeclaration {
     pub nodes: (
-        Option<Static<'a>>,
-        Keyword<'a>,
-        ConstraintIdentifier<'a>,
-        ConstraintBlock<'a>,
+        Option<Static>,
+        Keyword,
+        ConstraintIdentifier,
+        ConstraintBlock,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Static<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Static {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintBlock<'a> {
-    pub nodes: (Brace<'a, Vec<ConstraintBlockItem<'a>>>,),
+pub struct ConstraintBlock {
+    pub nodes: (Brace< Vec<ConstraintBlockItem>>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstraintBlockItem<'a> {
-    Solve(ConstraintBlockItemSolve<'a>),
-    ConstraintExpression(ConstraintExpression<'a>),
+pub enum ConstraintBlockItem {
+    Solve(ConstraintBlockItemSolve),
+    ConstraintExpression(ConstraintExpression),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintBlockItemSolve<'a> {
+pub struct ConstraintBlockItemSolve {
     pub nodes: (
-        Keyword<'a>,
-        SolveBeforeList<'a>,
-        Keyword<'a>,
-        SolveBeforeList<'a>,
-        Symbol<'a>,
+        Keyword,
+        SolveBeforeList,
+        Keyword,
+        SolveBeforeList,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SolveBeforeList<'a> {
-    pub nodes: (List<Symbol<'a>, ConstraintPrimary<'a>>,),
+pub struct SolveBeforeList {
+    pub nodes: (List<Symbol, ConstraintPrimary>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintPrimary<'a> {
+pub struct ConstraintPrimary {
     pub nodes: (
-        Option<ImplicitClassHandleOrClassScope<'a>>,
-        HierarchicalIdentifier<'a>,
-        Select<'a>,
+        Option<ImplicitClassHandleOrClassScope>,
+        HierarchicalIdentifier,
+        Select,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstraintExpression<'a> {
-    Expression(ConstraintExpressionExpression<'a>),
-    UniquenessConstraint((UniquenessConstraint<'a>, Symbol<'a>)),
-    Arrow(ConstraintExpressionArrow<'a>),
-    If(ConstraintExpressionIf<'a>),
-    Foreach(ConstraintExpressionForeach<'a>),
-    Disable(ConstraintExpressionDisable<'a>),
+pub enum ConstraintExpression {
+    Expression(ConstraintExpressionExpression),
+    UniquenessConstraint((UniquenessConstraint, Symbol)),
+    Arrow(ConstraintExpressionArrow),
+    If(ConstraintExpressionIf),
+    Foreach(ConstraintExpressionForeach),
+    Disable(ConstraintExpressionDisable),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintExpressionExpression<'a> {
-    pub nodes: (Option<Soft<'a>>, ExpressionOrDist<'a>, Symbol<'a>),
+pub struct ConstraintExpressionExpression {
+    pub nodes: (Option<Soft>, ExpressionOrDist, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct Soft<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Soft {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintExpressionArrow<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, ConstraintSet<'a>),
+pub struct ConstraintExpressionArrow {
+    pub nodes: (Expression, Symbol, ConstraintSet),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintExpressionIf<'a> {
+pub struct ConstraintExpressionIf {
     pub nodes: (
-        Keyword<'a>,
-        Paren<'a, Expression<'a>>,
-        ConstraintSet<'a>,
-        Option<(Keyword<'a>, ConstraintSet<'a>)>,
+        Keyword,
+        Paren< Expression>,
+        ConstraintSet,
+        Option<(Keyword, ConstraintSet)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintExpressionForeach<'a> {
+pub struct ConstraintExpressionForeach {
     pub nodes: (
-        Keyword<'a>,
+        Keyword,
         Paren<
-            'a,
+            
             (
-                PsOrHierarchicalArrayIdentifier<'a>,
-                Bracket<'a, LoopVariables<'a>>,
+                PsOrHierarchicalArrayIdentifier,
+                Bracket< LoopVariables>,
             ),
         >,
-        ConstraintSet<'a>,
+        ConstraintSet,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintExpressionDisable<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, ConstraintPrimary<'a>, Symbol<'a>),
+pub struct ConstraintExpressionDisable {
+    pub nodes: (Keyword, Keyword, ConstraintPrimary, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct UniquenessConstraint<'a> {
-    pub nodes: (Keyword<'a>, Brace<'a, OpenRangeList<'a>>),
+pub struct UniquenessConstraint {
+    pub nodes: (Keyword, Brace< OpenRangeList>),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstraintSet<'a> {
-    ConstraintExpression(Box<ConstraintExpression<'a>>),
-    Brace(ConstraintSetBrace<'a>),
+pub enum ConstraintSet {
+    ConstraintExpression(Box<ConstraintExpression>),
+    Brace(ConstraintSetBrace),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintSetBrace<'a> {
-    pub nodes: (Brace<'a, Vec<ConstraintExpression<'a>>>,),
+pub struct ConstraintSetBrace {
+    pub nodes: (Brace< Vec<ConstraintExpression>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DistList<'a> {
-    pub nodes: (List<Symbol<'a>, DistItem<'a>>,),
+pub struct DistList {
+    pub nodes: (List<Symbol, DistItem>,),
 }
 
 #[derive(Debug, Node)]
-pub struct DistItem<'a> {
-    pub nodes: (ValueRange<'a>, Option<DistWeight<'a>>),
+pub struct DistItem {
+    pub nodes: (ValueRange, Option<DistWeight>),
 }
 
 #[derive(Debug, Node)]
-pub enum DistWeight<'a> {
-    Equal(DistWeightEqual<'a>),
-    Divide(DistWeightDivide<'a>),
+pub enum DistWeight {
+    Equal(DistWeightEqual),
+    Divide(DistWeightDivide),
 }
 
 #[derive(Debug, Node)]
-pub struct DistWeightEqual<'a> {
-    pub nodes: (Symbol<'a>, Expression<'a>),
+pub struct DistWeightEqual {
+    pub nodes: (Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct DistWeightDivide<'a> {
-    pub nodes: (Symbol<'a>, Expression<'a>),
+pub struct DistWeightDivide {
+    pub nodes: (Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct ConstraintPrototype<'a> {
+pub struct ConstraintPrototype {
     pub nodes: (
-        Option<ConstraintPrototypeQualifier<'a>>,
-        Option<Static<'a>>,
-        Keyword<'a>,
-        ConstraintIdentifier<'a>,
-        Symbol<'a>,
+        Option<ConstraintPrototypeQualifier>,
+        Option<Static>,
+        Keyword,
+        ConstraintIdentifier,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ConstraintPrototypeQualifier<'a> {
-    Extern(Keyword<'a>),
-    Pure(Keyword<'a>),
+pub enum ConstraintPrototypeQualifier {
+    Extern(Keyword),
+    Pure(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct ExternConstraintDeclaration<'a> {
+pub struct ExternConstraintDeclaration {
     pub nodes: (
-        Option<Static<'a>>,
-        Keyword<'a>,
-        ClassScope<'a>,
-        ConstraintIdentifier<'a>,
-        ConstraintBlock<'a>,
+        Option<Static>,
+        Keyword,
+        ClassScope,
+        ConstraintIdentifier,
+        ConstraintBlock,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct IdentifierList<'a> {
-    pub nodes: (List<Symbol<'a>, Identifier<'a>>,),
+pub struct IdentifierList {
+    pub nodes: (List<Symbol, Identifier>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/interface_items.rs b/src/parser/source_text/interface_items.rs
index 8e8a475..c2ea4d4 100644
--- a/src/parser/source_text/interface_items.rs
+++ b/src/parser/source_text/interface_items.rs
@@ -9,51 +9,51 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum InterfaceOrGenerateItem<'a> {
-    Module(InterfaceOrGenerateItemModule<'a>),
-    Extern(InterfaceOrGenerateItemExtern<'a>),
+pub enum InterfaceOrGenerateItem {
+    Module(InterfaceOrGenerateItemModule),
+    Extern(InterfaceOrGenerateItemExtern),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceOrGenerateItemModule<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ModuleCommonItem<'a>),
+pub struct InterfaceOrGenerateItemModule {
+    pub nodes: (Vec<AttributeInstance>, ModuleCommonItem),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceOrGenerateItemExtern<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ExternTfDeclaration<'a>),
+pub struct InterfaceOrGenerateItemExtern {
+    pub nodes: (Vec<AttributeInstance>, ExternTfDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum ExternTfDeclaration<'a> {
-    Method(ExternTfDeclarationMethod<'a>),
-    Task(ExternTfDeclarationTask<'a>),
+pub enum ExternTfDeclaration {
+    Method(ExternTfDeclarationMethod),
+    Task(ExternTfDeclarationTask),
 }
 
 #[derive(Debug, Node)]
-pub struct ExternTfDeclarationMethod<'a> {
-    pub nodes: (Keyword<'a>, MethodPrototype<'a>, Symbol<'a>),
+pub struct ExternTfDeclarationMethod {
+    pub nodes: (Keyword, MethodPrototype, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ExternTfDeclarationTask<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, TaskPrototype<'a>, Symbol<'a>),
+pub struct ExternTfDeclarationTask {
+    pub nodes: (Keyword, Keyword, TaskPrototype, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum InterfaceItem<'a> {
-    PortDeclaration((PortDeclaration<'a>, Symbol<'a>)),
-    NonPortInterfaceItem(NonPortInterfaceItem<'a>),
+pub enum InterfaceItem {
+    PortDeclaration((PortDeclaration, Symbol)),
+    NonPortInterfaceItem(NonPortInterfaceItem),
 }
 
 #[derive(Debug, Node)]
-pub enum NonPortInterfaceItem<'a> {
-    GenerateRegion(GenerateRegion<'a>),
-    InterfaceOrGenerateItem(InterfaceOrGenerateItem<'a>),
-    ProgramDeclaration(ProgramDeclaration<'a>),
-    ModportDeclaration(ModportDeclaration<'a>),
-    InterfaceDeclaration(InterfaceDeclaration<'a>),
-    TimeunitsDeclaration(TimeunitsDeclaration<'a>),
+pub enum NonPortInterfaceItem {
+    GenerateRegion(GenerateRegion),
+    InterfaceOrGenerateItem(InterfaceOrGenerateItem),
+    ProgramDeclaration(ProgramDeclaration),
+    ModportDeclaration(ModportDeclaration),
+    InterfaceDeclaration(InterfaceDeclaration),
+    TimeunitsDeclaration(TimeunitsDeclaration),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/library_source_text.rs b/src/parser/source_text/library_source_text.rs
index 932bbd9..63faa19 100644
--- a/src/parser/source_text/library_source_text.rs
+++ b/src/parser/source_text/library_source_text.rs
@@ -9,37 +9,37 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct LibraryText<'a> {
-    pub nodes: (Vec<LibraryDescription<'a>>,),
+pub struct LibraryText {
+    pub nodes: (Vec<LibraryDescription>,),
 }
 
 #[derive(Debug, Node)]
-pub enum LibraryDescription<'a> {
-    LibraryDeclaration(LibraryDeclaration<'a>),
-    IncludeStatement(IncludeStatement<'a>),
-    ConfigDeclaration(ConfigDeclaration<'a>),
-    Null(Symbol<'a>),
+pub enum LibraryDescription {
+    LibraryDeclaration(LibraryDeclaration),
+    IncludeStatement(IncludeStatement),
+    ConfigDeclaration(ConfigDeclaration),
+    Null(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct LibraryDeclaration<'a> {
+pub struct LibraryDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        LibraryIdentifier<'a>,
-        List<Symbol<'a>, FilePathSpec<'a>>,
-        Option<(Keyword<'a>, List<Symbol<'a>, FilePathSpec<'a>>)>,
-        Symbol<'a>,
+        Keyword,
+        LibraryIdentifier,
+        List<Symbol, FilePathSpec>,
+        Option<(Keyword, List<Symbol, FilePathSpec>)>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct IncludeStatement<'a> {
-    pub nodes: (Keyword<'a>, FilePathSpec<'a>, Symbol<'a>),
+pub struct IncludeStatement {
+    pub nodes: (Keyword, FilePathSpec, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct FilePathSpec<'a> {
-    pub nodes: (StringLiteral<'a>,),
+pub struct FilePathSpec {
+    pub nodes: (StringLiteral,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/module_items.rs b/src/parser/source_text/module_items.rs
index 2ed6316..1c40105 100644
--- a/src/parser/source_text/module_items.rs
+++ b/src/parser/source_text/module_items.rs
@@ -9,209 +9,209 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ElaborationSystemTask<'a> {
-    Fatal(ElaborationSystemTaskFatal<'a>),
-    Error(ElaborationSystemTaskError<'a>),
-    Warning(ElaborationSystemTaskWarning<'a>),
-    Info(ElaborationSystemTaskInfo<'a>),
+pub enum ElaborationSystemTask {
+    Fatal(ElaborationSystemTaskFatal),
+    Error(ElaborationSystemTaskError),
+    Warning(ElaborationSystemTaskWarning),
+    Info(ElaborationSystemTaskInfo),
 }
 
 #[derive(Debug, Node)]
-pub struct ElaborationSystemTaskFatal<'a> {
+pub struct ElaborationSystemTaskFatal {
     pub nodes: (
-        Keyword<'a>,
-        Option<Paren<'a, (FinishNumber<'a>, Option<(Symbol<'a>, ListOfArguments<'a>)>)>>,
-        Symbol<'a>,
+        Keyword,
+        Option<Paren< (FinishNumber, Option<(Symbol, ListOfArguments)>)>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ElaborationSystemTaskError<'a> {
+pub struct ElaborationSystemTaskError {
     pub nodes: (
-        Keyword<'a>,
-        Option<Paren<'a, Option<ListOfArguments<'a>>>>,
-        Symbol<'a>,
+        Keyword,
+        Option<Paren< Option<ListOfArguments>>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ElaborationSystemTaskWarning<'a> {
+pub struct ElaborationSystemTaskWarning {
     pub nodes: (
-        Keyword<'a>,
-        Option<Paren<'a, Option<ListOfArguments<'a>>>>,
-        Symbol<'a>,
+        Keyword,
+        Option<Paren< Option<ListOfArguments>>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ElaborationSystemTaskInfo<'a> {
+pub struct ElaborationSystemTaskInfo {
     pub nodes: (
-        Keyword<'a>,
-        Option<Paren<'a, Option<ListOfArguments<'a>>>>,
-        Symbol<'a>,
+        Keyword,
+        Option<Paren< Option<ListOfArguments>>>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum FinishNumber<'a> {
-    Zero(Symbol<'a>),
-    One(Symbol<'a>),
-    Two(Symbol<'a>),
+pub enum FinishNumber {
+    Zero(Symbol),
+    One(Symbol),
+    Two(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleCommonItem<'a> {
-    ModuleOrGenerateItemDeclaration(ModuleOrGenerateItemDeclaration<'a>),
-    InterfaceInstantiation(InterfaceInstantiation<'a>),
-    ProgramInstantiation(ProgramInstantiation<'a>),
-    AssertionItem(AssertionItem<'a>),
-    BindDirective(BindDirective<'a>),
-    ContinuousAssign(ContinuousAssign<'a>),
-    NetAlias(NetAlias<'a>),
-    InitialConstruct(InitialConstruct<'a>),
-    FinalConstruct(FinalConstruct<'a>),
-    AlwaysConstruct(AlwaysConstruct<'a>),
-    LoopGenerateConstruct(Box<LoopGenerateConstruct<'a>>),
-    ConditionalGenerateConstruct(Box<ConditionalGenerateConstruct<'a>>),
-    ElaborationSystemTask(ElaborationSystemTask<'a>),
+pub enum ModuleCommonItem {
+    ModuleOrGenerateItemDeclaration(ModuleOrGenerateItemDeclaration),
+    InterfaceInstantiation(InterfaceInstantiation),
+    ProgramInstantiation(ProgramInstantiation),
+    AssertionItem(AssertionItem),
+    BindDirective(BindDirective),
+    ContinuousAssign(ContinuousAssign),
+    NetAlias(NetAlias),
+    InitialConstruct(InitialConstruct),
+    FinalConstruct(FinalConstruct),
+    AlwaysConstruct(AlwaysConstruct),
+    LoopGenerateConstruct(Box<LoopGenerateConstruct>),
+    ConditionalGenerateConstruct(Box<ConditionalGenerateConstruct>),
+    ElaborationSystemTask(ElaborationSystemTask),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleItem<'a> {
-    PortDeclaration((PortDeclaration<'a>, Symbol<'a>)),
-    NonPortModuleItem(NonPortModuleItem<'a>),
+pub enum ModuleItem {
+    PortDeclaration((PortDeclaration, Symbol)),
+    NonPortModuleItem(NonPortModuleItem),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleOrGenerateItem<'a> {
-    Parameter(ModuleOrGenerateItemParameter<'a>),
-    Gate(ModuleOrGenerateItemGate<'a>),
-    Udp(ModuleOrGenerateItemUdp<'a>),
-    Module(ModuleOrGenerateItemModule<'a>),
-    ModuleItem(Box<ModuleOrGenerateItemModuleItem<'a>>),
+pub enum ModuleOrGenerateItem {
+    Parameter(ModuleOrGenerateItemParameter),
+    Gate(ModuleOrGenerateItemGate),
+    Udp(ModuleOrGenerateItemUdp),
+    Module(ModuleOrGenerateItemModule),
+    ModuleItem(Box<ModuleOrGenerateItemModuleItem>),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemParameter<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ParameterOverride<'a>),
+pub struct ModuleOrGenerateItemParameter {
+    pub nodes: (Vec<AttributeInstance>, ParameterOverride),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemGate<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, GateInstantiation<'a>),
+pub struct ModuleOrGenerateItemGate {
+    pub nodes: (Vec<AttributeInstance>, GateInstantiation),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemUdp<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, UdpInstantiation<'a>),
+pub struct ModuleOrGenerateItemUdp {
+    pub nodes: (Vec<AttributeInstance>, UdpInstantiation),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemModule<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ModuleInstantiation<'a>),
+pub struct ModuleOrGenerateItemModule {
+    pub nodes: (Vec<AttributeInstance>, ModuleInstantiation),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemModuleItem<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ModuleCommonItem<'a>),
+pub struct ModuleOrGenerateItemModuleItem {
+    pub nodes: (Vec<AttributeInstance>, ModuleCommonItem),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleOrGenerateItemDeclaration<'a> {
-    PackageOrGenerateItemDeclaration(PackageOrGenerateItemDeclaration<'a>),
-    GenvarDeclaration(GenvarDeclaration<'a>),
-    ClockingDeclaration(ClockingDeclaration<'a>),
-    Clocking(ModuleOrGenerateItemDeclarationClocking<'a>),
-    Disable(ModuleOrGenerateItemDeclarationDisable<'a>),
+pub enum ModuleOrGenerateItemDeclaration {
+    PackageOrGenerateItemDeclaration(PackageOrGenerateItemDeclaration),
+    GenvarDeclaration(GenvarDeclaration),
+    ClockingDeclaration(ClockingDeclaration),
+    Clocking(ModuleOrGenerateItemDeclarationClocking),
+    Disable(ModuleOrGenerateItemDeclarationDisable),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemDeclarationClocking<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, ClockingIdentifier<'a>, Symbol<'a>),
+pub struct ModuleOrGenerateItemDeclarationClocking {
+    pub nodes: (Keyword, Keyword, ClockingIdentifier, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleOrGenerateItemDeclarationDisable<'a> {
+pub struct ModuleOrGenerateItemDeclarationDisable {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        Keyword<'a>,
-        ExpressionOrDist<'a>,
-        Symbol<'a>,
+        Keyword,
+        Keyword,
+        Keyword,
+        ExpressionOrDist,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum NonPortModuleItem<'a> {
-    GenerateRegion(GenerateRegion<'a>),
-    ModuleOrGenerateItem(ModuleOrGenerateItem<'a>),
-    SpecifyBlock(SpecifyBlock<'a>),
-    Specparam(NonPortModuleItemSpecparam<'a>),
-    ProgramDeclaration(ProgramDeclaration<'a>),
-    ModuleDeclaration(ModuleDeclaration<'a>),
-    InterfaceDeclaration(InterfaceDeclaration<'a>),
-    TimeunitsDeclaration(TimeunitsDeclaration<'a>),
+pub enum NonPortModuleItem {
+    GenerateRegion(GenerateRegion),
+    ModuleOrGenerateItem(ModuleOrGenerateItem),
+    SpecifyBlock(SpecifyBlock),
+    Specparam(NonPortModuleItemSpecparam),
+    ProgramDeclaration(ProgramDeclaration),
+    ModuleDeclaration(ModuleDeclaration),
+    InterfaceDeclaration(InterfaceDeclaration),
+    TimeunitsDeclaration(TimeunitsDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortModuleItemSpecparam<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, SpecparamDeclaration<'a>),
+pub struct NonPortModuleItemSpecparam {
+    pub nodes: (Vec<AttributeInstance>, SpecparamDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterOverride<'a> {
-    pub nodes: (Keyword<'a>, ListOfDefparamAssignments<'a>, Symbol<'a>),
+pub struct ParameterOverride {
+    pub nodes: (Keyword, ListOfDefparamAssignments, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub enum BindDirective<'a> {
-    Scope(BindDirectiveScope<'a>),
-    Instance(BindDirectiveInstance<'a>),
+pub enum BindDirective {
+    Scope(BindDirectiveScope),
+    Instance(BindDirectiveInstance),
 }
 
 #[derive(Debug, Node)]
-pub struct BindDirectiveScope<'a> {
+pub struct BindDirectiveScope {
     pub nodes: (
-        Keyword<'a>,
-        BindTargetScope<'a>,
-        Option<(Symbol<'a>, BindTargetInstanceList<'a>)>,
-        BindInstantiation<'a>,
-        Symbol<'a>,
+        Keyword,
+        BindTargetScope,
+        Option<(Symbol, BindTargetInstanceList)>,
+        BindInstantiation,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct BindDirectiveInstance<'a> {
+pub struct BindDirectiveInstance {
     pub nodes: (
-        Keyword<'a>,
-        BindTargetInstance<'a>,
-        BindInstantiation<'a>,
-        Symbol<'a>,
+        Keyword,
+        BindTargetInstance,
+        BindInstantiation,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum BindTargetScope<'a> {
-    ModuleIdentifier(ModuleIdentifier<'a>),
-    InterfaceIdentifier(InterfaceIdentifier<'a>),
+pub enum BindTargetScope {
+    ModuleIdentifier(ModuleIdentifier),
+    InterfaceIdentifier(InterfaceIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct BindTargetInstance<'a> {
-    pub nodes: (HierarchicalIdentifier<'a>, ConstantBitSelect<'a>),
+pub struct BindTargetInstance {
+    pub nodes: (HierarchicalIdentifier, ConstantBitSelect),
 }
 
 #[derive(Debug, Node)]
-pub struct BindTargetInstanceList<'a> {
-    pub nodes: (List<Symbol<'a>, BindTargetInstance<'a>>,),
+pub struct BindTargetInstanceList {
+    pub nodes: (List<Symbol, BindTargetInstance>,),
 }
 
 #[derive(Debug, Node)]
-pub enum BindInstantiation<'a> {
-    ProgramInstantiation(ProgramInstantiation<'a>),
-    ModuleInstantiation(ModuleInstantiation<'a>),
-    InterfaceInstantiation(InterfaceInstantiation<'a>),
-    CheckerInstantiation(CheckerInstantiation<'a>),
+pub enum BindInstantiation {
+    ProgramInstantiation(ProgramInstantiation),
+    ModuleInstantiation(ModuleInstantiation),
+    InterfaceInstantiation(InterfaceInstantiation),
+    CheckerInstantiation(CheckerInstantiation),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/module_parameters_and_ports.rs b/src/parser/source_text/module_parameters_and_ports.rs
index e7cf275..34e6b47 100644
--- a/src/parser/source_text/module_parameters_and_ports.rs
+++ b/src/parser/source_text/module_parameters_and_ports.rs
@@ -9,210 +9,210 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ParameterPortList<'a> {
-    Assignment(ParameterPortListAssignment<'a>),
-    Declaration(ParameterPortListDeclaration<'a>),
-    Empty((Symbol<'a>, Symbol<'a>, Symbol<'a>)),
+pub enum ParameterPortList {
+    Assignment(ParameterPortListAssignment),
+    Declaration(ParameterPortListDeclaration),
+    Empty((Symbol, Symbol, Symbol)),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterPortListAssignment<'a> {
+pub struct ParameterPortListAssignment {
     pub nodes: (
-        Symbol<'a>,
+        Symbol,
         Paren<
-            'a,
+            
             (
-                ListOfParamAssignments<'a>,
-                Vec<(Symbol<'a>, ParameterPortDeclaration<'a>)>,
+                ListOfParamAssignments,
+                Vec<(Symbol, ParameterPortDeclaration)>,
             ),
         >,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterPortListDeclaration<'a> {
+pub struct ParameterPortListDeclaration {
     pub nodes: (
-        Symbol<'a>,
-        Paren<'a, List<Symbol<'a>, ParameterPortDeclaration<'a>>>,
+        Symbol,
+        Paren< List<Symbol, ParameterPortDeclaration>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ParameterPortDeclaration<'a> {
-    ParameterDeclaration(ParameterDeclaration<'a>),
-    LocalParameterDeclaration(LocalParameterDeclaration<'a>),
-    ParamList(ParameterPortDeclarationParamList<'a>),
-    TypeList(ParameterPortDeclarationTypeList<'a>),
+pub enum ParameterPortDeclaration {
+    ParameterDeclaration(ParameterDeclaration),
+    LocalParameterDeclaration(LocalParameterDeclaration),
+    ParamList(ParameterPortDeclarationParamList),
+    TypeList(ParameterPortDeclarationTypeList),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterPortDeclarationParamList<'a> {
-    pub nodes: (DataType<'a>, ListOfParamAssignments<'a>),
+pub struct ParameterPortDeclarationParamList {
+    pub nodes: (DataType, ListOfParamAssignments),
 }
 
 #[derive(Debug, Node)]
-pub struct ParameterPortDeclarationTypeList<'a> {
-    pub nodes: (Keyword<'a>, ListOfTypeAssignments<'a>),
+pub struct ParameterPortDeclarationTypeList {
+    pub nodes: (Keyword, ListOfTypeAssignments),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPorts<'a> {
-    pub nodes: (Paren<'a, List<Symbol<'a>, Port<'a>>>,),
+pub struct ListOfPorts {
+    pub nodes: (Paren< List<Symbol, Port>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPortDeclarations<'a> {
+pub struct ListOfPortDeclarations {
     pub nodes: (
-        Paren<'a, Option<List<Symbol<'a>, (Vec<AttributeInstance<'a>>, AnsiPortDeclaration<'a>)>>>,
+        Paren< Option<List<Symbol, (Vec<AttributeInstance>, AnsiPortDeclaration)>>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PortDeclaration<'a> {
-    Inout(PortDeclarationInout<'a>),
-    Input(PortDeclarationInput<'a>),
-    Output(PortDeclarationOutput<'a>),
-    Ref(PortDeclarationRef<'a>),
-    Interface(PortDeclarationInterface<'a>),
+pub enum PortDeclaration {
+    Inout(PortDeclarationInout),
+    Input(PortDeclarationInput),
+    Output(PortDeclarationOutput),
+    Ref(PortDeclarationRef),
+    Interface(PortDeclarationInterface),
 }
 
 #[derive(Debug, Node)]
-pub struct PortDeclarationInout<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, InoutDeclaration<'a>),
+pub struct PortDeclarationInout {
+    pub nodes: (Vec<AttributeInstance>, InoutDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct PortDeclarationInput<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, InputDeclaration<'a>),
+pub struct PortDeclarationInput {
+    pub nodes: (Vec<AttributeInstance>, InputDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct PortDeclarationOutput<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, OutputDeclaration<'a>),
+pub struct PortDeclarationOutput {
+    pub nodes: (Vec<AttributeInstance>, OutputDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct PortDeclarationRef<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, RefDeclaration<'a>),
+pub struct PortDeclarationRef {
+    pub nodes: (Vec<AttributeInstance>, RefDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct PortDeclarationInterface<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, InterfacePortDeclaration<'a>),
+pub struct PortDeclarationInterface {
+    pub nodes: (Vec<AttributeInstance>, InterfacePortDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum Port<'a> {
-    NonNamed(PortNonNamed<'a>),
-    Named(PortNamed<'a>),
+pub enum Port {
+    NonNamed(PortNonNamed),
+    Named(PortNamed),
 }
 
 #[derive(Debug, Node)]
-pub struct PortNonNamed<'a> {
-    pub nodes: (Option<PortExpression<'a>>,),
+pub struct PortNonNamed {
+    pub nodes: (Option<PortExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PortNamed<'a> {
+pub struct PortNamed {
     pub nodes: (
-        Symbol<'a>,
-        PortIdentifier<'a>,
-        Paren<'a, Option<PortExpression<'a>>>,
+        Symbol,
+        PortIdentifier,
+        Paren< Option<PortExpression>>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum PortExpression<'a> {
-    PortReference(PortReference<'a>),
-    Brace(PortExpressionBrace<'a>),
+pub enum PortExpression {
+    PortReference(PortReference),
+    Brace(PortExpressionBrace),
 }
 
 #[derive(Debug, Node)]
-pub struct PortExpressionBrace<'a> {
-    pub nodes: (Brace<'a, List<Symbol<'a>, PortReference<'a>>>,),
+pub struct PortExpressionBrace {
+    pub nodes: (Brace< List<Symbol, PortReference>>,),
 }
 
 #[derive(Debug, Node)]
-pub struct PortReference<'a> {
-    pub nodes: (PortIdentifier<'a>, ConstantSelect<'a>),
+pub struct PortReference {
+    pub nodes: (PortIdentifier, ConstantSelect),
 }
 
 #[derive(Debug, Node)]
-pub enum PortDirection<'a> {
-    Input(Keyword<'a>),
-    Output(Keyword<'a>),
-    Inout(Keyword<'a>),
-    Ref(Keyword<'a>),
+pub enum PortDirection {
+    Input(Keyword),
+    Output(Keyword),
+    Inout(Keyword),
+    Ref(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub struct NetPortHeader<'a> {
-    pub nodes: (Option<PortDirection<'a>>, NetPortType<'a>),
+pub struct NetPortHeader {
+    pub nodes: (Option<PortDirection>, NetPortType),
 }
 
 #[derive(Debug, Node)]
-pub struct VariablePortHeader<'a> {
-    pub nodes: (Option<PortDirection<'a>>, VariablePortType<'a>),
+pub struct VariablePortHeader {
+    pub nodes: (Option<PortDirection>, VariablePortType),
 }
 
 #[derive(Debug, Node)]
-pub enum InterfacePortHeader<'a> {
-    Identifier(InterfacePortHeaderIdentifier<'a>),
-    Interface(InterfacePortHeaderInterface<'a>),
+pub enum InterfacePortHeader {
+    Identifier(InterfacePortHeaderIdentifier),
+    Interface(InterfacePortHeaderInterface),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfacePortHeaderIdentifier<'a> {
+pub struct InterfacePortHeaderIdentifier {
     pub nodes: (
-        InterfaceIdentifier<'a>,
-        Option<(Symbol<'a>, ModportIdentifier<'a>)>,
+        InterfaceIdentifier,
+        Option<(Symbol, ModportIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfacePortHeaderInterface<'a> {
-    pub nodes: (Keyword<'a>, Option<(Symbol<'a>, ModportIdentifier<'a>)>),
+pub struct InterfacePortHeaderInterface {
+    pub nodes: (Keyword, Option<(Symbol, ModportIdentifier)>),
 }
 
 #[derive(Debug, Node)]
-pub enum NetPortHeaderOrInterfacePortHeader<'a> {
-    NetPortHeader(NetPortHeader<'a>),
-    InterfacePortHeader(InterfacePortHeader<'a>),
+pub enum NetPortHeaderOrInterfacePortHeader {
+    NetPortHeader(NetPortHeader),
+    InterfacePortHeader(InterfacePortHeader),
 }
 #[derive(Debug, Node)]
-pub enum AnsiPortDeclaration<'a> {
-    Net(AnsiPortDeclarationNet<'a>),
-    Variable(AnsiPortDeclarationVariable<'a>),
-    Paren(AnsiPortDeclarationParen<'a>),
+pub enum AnsiPortDeclaration {
+    Net(AnsiPortDeclarationNet),
+    Variable(AnsiPortDeclarationVariable),
+    Paren(AnsiPortDeclarationParen),
 }
 
 #[derive(Debug, Node)]
-pub struct AnsiPortDeclarationNet<'a> {
+pub struct AnsiPortDeclarationNet {
     pub nodes: (
-        Option<NetPortHeaderOrInterfacePortHeader<'a>>,
-        PortIdentifier<'a>,
-        Vec<UnpackedDimension<'a>>,
-        Option<(Symbol<'a>, ConstantExpression<'a>)>,
+        Option<NetPortHeaderOrInterfacePortHeader>,
+        PortIdentifier,
+        Vec<UnpackedDimension>,
+        Option<(Symbol, ConstantExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct AnsiPortDeclarationVariable<'a> {
+pub struct AnsiPortDeclarationVariable {
     pub nodes: (
-        Option<VariablePortHeader<'a>>,
-        PortIdentifier<'a>,
-        Vec<VariableDimension<'a>>,
-        Option<(Symbol<'a>, ConstantExpression<'a>)>,
+        Option<VariablePortHeader>,
+        PortIdentifier,
+        Vec<VariableDimension>,
+        Option<(Symbol, ConstantExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct AnsiPortDeclarationParen<'a> {
+pub struct AnsiPortDeclarationParen {
     pub nodes: (
-        Option<PortDirection<'a>>,
-        Symbol<'a>,
-        PortIdentifier<'a>,
-        Paren<'a, Option<Expression<'a>>>,
+        Option<PortDirection>,
+        Symbol,
+        PortIdentifier,
+        Paren< Option<Expression>>,
     ),
 }
 
diff --git a/src/parser/source_text/package_items.rs b/src/parser/source_text/package_items.rs
index 7c81fe2..0fd104b 100644
--- a/src/parser/source_text/package_items.rs
+++ b/src/parser/source_text/package_items.rs
@@ -9,49 +9,49 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum PackageItem<'a> {
-    PackageOrGenerateItemDeclaration(PackageOrGenerateItemDeclaration<'a>),
-    AnonymousProgram(AnonymousProgram<'a>),
-    PackageExportDeclaration(PackageExportDeclaration<'a>),
-    TimeunitsDeclaration(TimeunitsDeclaration<'a>),
+pub enum PackageItem {
+    PackageOrGenerateItemDeclaration(PackageOrGenerateItemDeclaration),
+    AnonymousProgram(AnonymousProgram),
+    PackageExportDeclaration(PackageExportDeclaration),
+    TimeunitsDeclaration(TimeunitsDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub enum PackageOrGenerateItemDeclaration<'a> {
-    NetDeclaration(NetDeclaration<'a>),
-    DataDeclaration(DataDeclaration<'a>),
-    TaskDeclaration(TaskDeclaration<'a>),
-    FunctionDeclaration(FunctionDeclaration<'a>),
-    CheckerDeclaration(CheckerDeclaration<'a>),
-    DpiImportExport(DpiImportExport<'a>),
-    ExternConstraintDeclaration(ExternConstraintDeclaration<'a>),
-    ClassDeclaration(ClassDeclaration<'a>),
-    ClassConstructorDeclaration(ClassConstructorDeclaration<'a>),
-    LocalParameterDeclaration((LocalParameterDeclaration<'a>, Symbol<'a>)),
-    ParameterDeclaration((ParameterDeclaration<'a>, Symbol<'a>)),
-    CovergroupDeclaration(CovergroupDeclaration<'a>),
-    AssertionItemDeclaration(AssertionItemDeclaration<'a>),
-    Empty(Symbol<'a>),
+pub enum PackageOrGenerateItemDeclaration {
+    NetDeclaration(NetDeclaration),
+    DataDeclaration(DataDeclaration),
+    TaskDeclaration(TaskDeclaration),
+    FunctionDeclaration(FunctionDeclaration),
+    CheckerDeclaration(CheckerDeclaration),
+    DpiImportExport(DpiImportExport),
+    ExternConstraintDeclaration(ExternConstraintDeclaration),
+    ClassDeclaration(ClassDeclaration),
+    ClassConstructorDeclaration(ClassConstructorDeclaration),
+    LocalParameterDeclaration((LocalParameterDeclaration, Symbol)),
+    ParameterDeclaration((ParameterDeclaration, Symbol)),
+    CovergroupDeclaration(CovergroupDeclaration),
+    AssertionItemDeclaration(AssertionItemDeclaration),
+    Empty(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct AnonymousProgram<'a> {
+pub struct AnonymousProgram {
     pub nodes: (
-        Keyword<'a>,
-        Symbol<'a>,
-        Vec<AnonymousProgramItem<'a>>,
-        Keyword<'a>,
+        Keyword,
+        Symbol,
+        Vec<AnonymousProgramItem>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum AnonymousProgramItem<'a> {
-    TaskDeclaration(TaskDeclaration<'a>),
-    FunctionDeclaration(FunctionDeclaration<'a>),
-    ClassDeclaration(ClassDeclaration<'a>),
-    CovergroupDeclaration(CovergroupDeclaration<'a>),
-    ClassConstructorDeclaration(ClassConstructorDeclaration<'a>),
-    Empty(Symbol<'a>),
+pub enum AnonymousProgramItem {
+    TaskDeclaration(TaskDeclaration),
+    FunctionDeclaration(FunctionDeclaration),
+    ClassDeclaration(ClassDeclaration),
+    CovergroupDeclaration(CovergroupDeclaration),
+    ClassConstructorDeclaration(ClassConstructorDeclaration),
+    Empty(Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/program_items.rs b/src/parser/source_text/program_items.rs
index 0396bcf..8d3d9aa 100644
--- a/src/parser/source_text/program_items.rs
+++ b/src/parser/source_text/program_items.rs
@@ -9,56 +9,56 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum ProgramItem<'a> {
-    PortDeclaration((PortDeclaration<'a>, Symbol<'a>)),
-    NonPortProgramItem(NonPortProgramItem<'a>),
+pub enum ProgramItem {
+    PortDeclaration((PortDeclaration, Symbol)),
+    NonPortProgramItem(NonPortProgramItem),
 }
 
 #[derive(Debug, Node)]
-pub enum NonPortProgramItem<'a> {
-    Assign(NonPortProgramItemAssign<'a>),
-    Module(NonPortProgramItemModule<'a>),
-    Initial(NonPortProgramItemInitial<'a>),
-    Final(NonPortProgramItemFinal<'a>),
-    Assertion(NonPortProgramItemAssertion<'a>),
-    TimeunitsDeclaration(TimeunitsDeclaration<'a>),
-    ProgramGenerateItem(ProgramGenerateItem<'a>),
+pub enum NonPortProgramItem {
+    Assign(NonPortProgramItemAssign),
+    Module(NonPortProgramItemModule),
+    Initial(NonPortProgramItemInitial),
+    Final(NonPortProgramItemFinal),
+    Assertion(NonPortProgramItemAssertion),
+    TimeunitsDeclaration(TimeunitsDeclaration),
+    ProgramGenerateItem(ProgramGenerateItem),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortProgramItemAssign<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ContinuousAssign<'a>),
+pub struct NonPortProgramItemAssign {
+    pub nodes: (Vec<AttributeInstance>, ContinuousAssign),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortProgramItemModule<'a> {
+pub struct NonPortProgramItemModule {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ModuleOrGenerateItemDeclaration<'a>,
+        Vec<AttributeInstance>,
+        ModuleOrGenerateItemDeclaration,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortProgramItemInitial<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, InitialConstruct<'a>),
+pub struct NonPortProgramItemInitial {
+    pub nodes: (Vec<AttributeInstance>, InitialConstruct),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortProgramItemFinal<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, FinalConstruct<'a>),
+pub struct NonPortProgramItemFinal {
+    pub nodes: (Vec<AttributeInstance>, FinalConstruct),
 }
 
 #[derive(Debug, Node)]
-pub struct NonPortProgramItemAssertion<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, ConcurrentAssertionItem<'a>),
+pub struct NonPortProgramItemAssertion {
+    pub nodes: (Vec<AttributeInstance>, ConcurrentAssertionItem),
 }
 
 #[derive(Debug, Node)]
-pub enum ProgramGenerateItem<'a> {
-    LoopGenerateConstruct(LoopGenerateConstruct<'a>),
-    ConditionalGenerateConstruct(ConditionalGenerateConstruct<'a>),
-    GenerateRegion(GenerateRegion<'a>),
-    ElaborationSystemTask(ElaborationSystemTask<'a>),
+pub enum ProgramGenerateItem {
+    LoopGenerateConstruct(LoopGenerateConstruct),
+    ConditionalGenerateConstruct(ConditionalGenerateConstruct),
+    GenerateRegion(GenerateRegion),
+    ElaborationSystemTask(ElaborationSystemTask),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/source_text/system_verilog_source_text.rs b/src/parser/source_text/system_verilog_source_text.rs
index a91f51a..2eea592 100644
--- a/src/parser/source_text/system_verilog_source_text.rs
+++ b/src/parser/source_text/system_verilog_source_text.rs
@@ -9,429 +9,429 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct SourceText<'a> {
-    pub nodes: (Option<TimeunitsDeclaration<'a>>, Vec<Description<'a>>),
+pub struct SourceText {
+    pub nodes: (Option<TimeunitsDeclaration>, Vec<Description>),
 }
 
 #[derive(Debug, Node)]
-pub enum Description<'a> {
-    ModuleDeclaration(ModuleDeclaration<'a>),
-    UdpDeclaration(UdpDeclaration<'a>),
-    InterfaceDeclaration(InterfaceDeclaration<'a>),
-    ProgramDeclaration(ProgramDeclaration<'a>),
-    PackageDeclaration(PackageDeclaration<'a>),
-    PackageItem(DescriptionPackageItem<'a>),
-    BindDirective(DescriptionBindDirective<'a>),
-    ConfigDeclaration(ConfigDeclaration<'a>),
+pub enum Description {
+    ModuleDeclaration(ModuleDeclaration),
+    UdpDeclaration(UdpDeclaration),
+    InterfaceDeclaration(InterfaceDeclaration),
+    ProgramDeclaration(ProgramDeclaration),
+    PackageDeclaration(PackageDeclaration),
+    PackageItem(DescriptionPackageItem),
+    BindDirective(DescriptionBindDirective),
+    ConfigDeclaration(ConfigDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct DescriptionPackageItem<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, PackageItem<'a>),
+pub struct DescriptionPackageItem {
+    pub nodes: (Vec<AttributeInstance>, PackageItem),
 }
 
 #[derive(Debug, Node)]
-pub struct DescriptionBindDirective<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, BindDirective<'a>),
+pub struct DescriptionBindDirective {
+    pub nodes: (Vec<AttributeInstance>, BindDirective),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleNonansiHeader<'a> {
+pub struct ModuleNonansiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ModuleKeyword<'a>,
-        Option<Lifetime<'a>>,
-        ModuleIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        ListOfPorts<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        ModuleKeyword,
+        Option<Lifetime>,
+        ModuleIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        ListOfPorts,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleAnsiHeader<'a> {
+pub struct ModuleAnsiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ModuleKeyword<'a>,
-        Option<Lifetime<'a>>,
-        ModuleIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        Option<ListOfPortDeclarations<'a>>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        ModuleKeyword,
+        Option<Lifetime>,
+        ModuleIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        Option<ListOfPortDeclarations>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleDeclaration<'a> {
-    Nonansi(ModuleDeclarationNonansi<'a>),
-    Ansi(ModuleDeclarationAnsi<'a>),
-    Wildcard(ModuleDeclarationWildcard<'a>),
-    ExternNonansi(ModuleDeclarationExternNonansi<'a>),
-    ExternAnsi(ModuleDeclarationExternAnsi<'a>),
+pub enum ModuleDeclaration {
+    Nonansi(ModuleDeclarationNonansi),
+    Ansi(ModuleDeclarationAnsi),
+    Wildcard(ModuleDeclarationWildcard),
+    ExternNonansi(ModuleDeclarationExternNonansi),
+    ExternAnsi(ModuleDeclarationExternAnsi),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleDeclarationNonansi<'a> {
+pub struct ModuleDeclarationNonansi {
     pub nodes: (
-        ModuleNonansiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<ModuleItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ModuleIdentifier<'a>)>,
+        ModuleNonansiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<ModuleItem>,
+        Keyword,
+        Option<(Symbol, ModuleIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleDeclarationAnsi<'a> {
+pub struct ModuleDeclarationAnsi {
     pub nodes: (
-        ModuleAnsiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<NonPortModuleItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ModuleIdentifier<'a>)>,
+        ModuleAnsiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<NonPortModuleItem>,
+        Keyword,
+        Option<(Symbol, ModuleIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleDeclarationWildcard<'a> {
+pub struct ModuleDeclarationWildcard {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        ModuleKeyword<'a>,
-        Option<Lifetime<'a>>,
-        ModuleIdentifier<'a>,
-        Paren<'a, Symbol<'a>>,
-        Symbol<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<ModuleItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ModuleIdentifier<'a>)>,
+        Vec<AttributeInstance>,
+        ModuleKeyword,
+        Option<Lifetime>,
+        ModuleIdentifier,
+        Paren< Symbol>,
+        Symbol,
+        Option<TimeunitsDeclaration>,
+        Vec<ModuleItem>,
+        Keyword,
+        Option<(Symbol, ModuleIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleDeclarationExternNonansi<'a> {
-    pub nodes: (Keyword<'a>, ModuleNonansiHeader<'a>),
+pub struct ModuleDeclarationExternNonansi {
+    pub nodes: (Keyword, ModuleNonansiHeader),
 }
 
 #[derive(Debug, Node)]
-pub struct ModuleDeclarationExternAnsi<'a> {
-    pub nodes: (Keyword<'a>, ModuleAnsiHeader<'a>),
+pub struct ModuleDeclarationExternAnsi {
+    pub nodes: (Keyword, ModuleAnsiHeader),
 }
 
 #[derive(Debug, Node)]
-pub enum ModuleKeyword<'a> {
-    Module(Keyword<'a>),
-    Macromodule(Keyword<'a>),
+pub enum ModuleKeyword {
+    Module(Keyword),
+    Macromodule(Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum InterfaceDeclaration<'a> {
-    Nonansi(InterfaceDeclarationNonansi<'a>),
-    Ansi(InterfaceDeclarationAnsi<'a>),
-    Wildcard(InterfaceDeclarationWildcard<'a>),
-    ExternNonansi(InterfaceDeclarationExternNonansi<'a>),
-    ExternAnsi(InterfaceDeclarationExternAnsi<'a>),
+pub enum InterfaceDeclaration {
+    Nonansi(InterfaceDeclarationNonansi),
+    Ansi(InterfaceDeclarationAnsi),
+    Wildcard(InterfaceDeclarationWildcard),
+    ExternNonansi(InterfaceDeclarationExternNonansi),
+    ExternAnsi(InterfaceDeclarationExternAnsi),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceDeclarationNonansi<'a> {
+pub struct InterfaceDeclarationNonansi {
     pub nodes: (
-        InterfaceNonansiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<InterfaceItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, InterfaceIdentifier<'a>)>,
+        InterfaceNonansiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<InterfaceItem>,
+        Keyword,
+        Option<(Symbol, InterfaceIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceDeclarationAnsi<'a> {
+pub struct InterfaceDeclarationAnsi {
     pub nodes: (
-        InterfaceAnsiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<NonPortInterfaceItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, InterfaceIdentifier<'a>)>,
+        InterfaceAnsiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<NonPortInterfaceItem>,
+        Keyword,
+        Option<(Symbol, InterfaceIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceDeclarationWildcard<'a> {
+pub struct InterfaceDeclarationWildcard {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        InterfaceIdentifier<'a>,
-        Paren<'a, Symbol<'a>>,
-        Symbol<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<InterfaceItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, InterfaceIdentifier<'a>)>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        InterfaceIdentifier,
+        Paren< Symbol>,
+        Symbol,
+        Option<TimeunitsDeclaration>,
+        Vec<InterfaceItem>,
+        Keyword,
+        Option<(Symbol, InterfaceIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceDeclarationExternNonansi<'a> {
-    pub nodes: (Keyword<'a>, InterfaceNonansiHeader<'a>),
+pub struct InterfaceDeclarationExternNonansi {
+    pub nodes: (Keyword, InterfaceNonansiHeader),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceDeclarationExternAnsi<'a> {
-    pub nodes: (Keyword<'a>, InterfaceAnsiHeader<'a>),
+pub struct InterfaceDeclarationExternAnsi {
+    pub nodes: (Keyword, InterfaceAnsiHeader),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceNonansiHeader<'a> {
+pub struct InterfaceNonansiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        InterfaceIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        ListOfPorts<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        InterfaceIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        ListOfPorts,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceAnsiHeader<'a> {
+pub struct InterfaceAnsiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        InterfaceIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        Option<ListOfPortDeclarations<'a>>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        InterfaceIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        Option<ListOfPortDeclarations>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum ProgramDeclaration<'a> {
-    Nonansi(ProgramDeclarationNonansi<'a>),
-    Ansi(ProgramDeclarationAnsi<'a>),
-    Wildcard(ProgramDeclarationWildcard<'a>),
-    ExternNonansi(ProgramDeclarationExternNonansi<'a>),
-    ExternAnsi(ProgramDeclarationExternAnsi<'a>),
+pub enum ProgramDeclaration {
+    Nonansi(ProgramDeclarationNonansi),
+    Ansi(ProgramDeclarationAnsi),
+    Wildcard(ProgramDeclarationWildcard),
+    ExternNonansi(ProgramDeclarationExternNonansi),
+    ExternAnsi(ProgramDeclarationExternAnsi),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramDeclarationNonansi<'a> {
+pub struct ProgramDeclarationNonansi {
     pub nodes: (
-        ProgramNonansiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<ProgramItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ProgramIdentifier<'a>)>,
+        ProgramNonansiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<ProgramItem>,
+        Keyword,
+        Option<(Symbol, ProgramIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramDeclarationAnsi<'a> {
+pub struct ProgramDeclarationAnsi {
     pub nodes: (
-        ProgramAnsiHeader<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<NonPortProgramItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ProgramIdentifier<'a>)>,
+        ProgramAnsiHeader,
+        Option<TimeunitsDeclaration>,
+        Vec<NonPortProgramItem>,
+        Keyword,
+        Option<(Symbol, ProgramIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramDeclarationWildcard<'a> {
+pub struct ProgramDeclarationWildcard {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        ProgramIdentifier<'a>,
-        Paren<'a, Symbol<'a>>,
-        Symbol<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<ProgramItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ProgramIdentifier<'a>)>,
+        Vec<AttributeInstance>,
+        Keyword,
+        ProgramIdentifier,
+        Paren< Symbol>,
+        Symbol,
+        Option<TimeunitsDeclaration>,
+        Vec<ProgramItem>,
+        Keyword,
+        Option<(Symbol, ProgramIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramDeclarationExternNonansi<'a> {
-    pub nodes: (Keyword<'a>, ProgramNonansiHeader<'a>),
+pub struct ProgramDeclarationExternNonansi {
+    pub nodes: (Keyword, ProgramNonansiHeader),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramDeclarationExternAnsi<'a> {
-    pub nodes: (Keyword<'a>, ProgramAnsiHeader<'a>),
+pub struct ProgramDeclarationExternAnsi {
+    pub nodes: (Keyword, ProgramAnsiHeader),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramNonansiHeader<'a> {
+pub struct ProgramNonansiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        ProgramIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        ListOfPorts<'a>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        ProgramIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        ListOfPorts,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ProgramAnsiHeader<'a> {
+pub struct ProgramAnsiHeader {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        ProgramIdentifier<'a>,
-        Vec<PackageImportDeclaration<'a>>,
-        Option<ParameterPortList<'a>>,
-        Option<ListOfPortDeclarations<'a>>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        ProgramIdentifier,
+        Vec<PackageImportDeclaration>,
+        Option<ParameterPortList>,
+        Option<ListOfPortDeclarations>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CheckerDeclaration<'a> {
+pub struct CheckerDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        CheckerIdentifier<'a>,
-        Option<Paren<'a, Option<CheckerPortList<'a>>>>,
-        Symbol<'a>,
-        Vec<(Vec<AttributeInstance<'a>>, CheckerOrGenerateItem<'a>)>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, CheckerIdentifier<'a>)>,
+        Keyword,
+        CheckerIdentifier,
+        Option<Paren< Option<CheckerPortList>>>,
+        Symbol,
+        Vec<(Vec<AttributeInstance>, CheckerOrGenerateItem)>,
+        Keyword,
+        Option<(Symbol, CheckerIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ClassDeclaration<'a> {
+pub struct ClassDeclaration {
     pub nodes: (
-        Option<Virtual<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        ClassIdentifier<'a>,
-        Option<ParameterPortList<'a>>,
+        Option<Virtual>,
+        Keyword,
+        Option<Lifetime>,
+        ClassIdentifier,
+        Option<ParameterPortList>,
         Option<(
-            Keyword<'a>,
-            ClassType<'a>,
-            Option<Paren<'a, ListOfArguments<'a>>>,
+            Keyword,
+            ClassType,
+            Option<Paren< ListOfArguments>>,
         )>,
-        Option<(Keyword<'a>, List<Symbol<'a>, InterfaceClassType<'a>>)>,
-        Symbol<'a>,
-        Vec<ClassItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ClassIdentifier<'a>)>,
+        Option<(Keyword, List<Symbol, InterfaceClassType>)>,
+        Symbol,
+        Vec<ClassItem>,
+        Keyword,
+        Option<(Symbol, ClassIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct Virtual<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct Virtual {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceClassType<'a> {
-    pub nodes: (PsClassIdentifier<'a>, Option<ParameterValueAssignment<'a>>),
+pub struct InterfaceClassType {
+    pub nodes: (PsClassIdentifier, Option<ParameterValueAssignment>),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceClassDeclaration<'a> {
+pub struct InterfaceClassDeclaration {
     pub nodes: (
-        Keyword<'a>,
-        Keyword<'a>,
-        ClassIdentifier<'a>,
-        Option<ParameterPortList<'a>>,
-        Option<(Keyword<'a>, List<Symbol<'a>, InterfaceClassType<'a>>)>,
-        Symbol<'a>,
-        Vec<InterfaceClassItem<'a>>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, ClassIdentifier<'a>)>,
+        Keyword,
+        Keyword,
+        ClassIdentifier,
+        Option<ParameterPortList>,
+        Option<(Keyword, List<Symbol, InterfaceClassType>)>,
+        Symbol,
+        Vec<InterfaceClassItem>,
+        Keyword,
+        Option<(Symbol, ClassIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum InterfaceClassItem<'a> {
-    TypeDeclaration(TypeDeclaration<'a>),
-    Method(InterfaceClassItemMethod<'a>),
-    LocalParameterDeclaration((LocalParameterDeclaration<'a>, Symbol<'a>)),
-    ParameterDeclaration((ParameterDeclaration<'a>, Symbol<'a>)),
-    Null(Symbol<'a>),
+pub enum InterfaceClassItem {
+    TypeDeclaration(TypeDeclaration),
+    Method(InterfaceClassItemMethod),
+    LocalParameterDeclaration((LocalParameterDeclaration, Symbol)),
+    ParameterDeclaration((ParameterDeclaration, Symbol)),
+    Null(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceClassItemMethod<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, InterfaceClassMethod<'a>),
+pub struct InterfaceClassItemMethod {
+    pub nodes: (Vec<AttributeInstance>, InterfaceClassMethod),
 }
 
 #[derive(Debug, Node)]
-pub struct InterfaceClassMethod<'a> {
-    pub nodes: (Keyword<'a>, Keyword<'a>, MethodPrototype<'a>, Symbol<'a>),
+pub struct InterfaceClassMethod {
+    pub nodes: (Keyword, Keyword, MethodPrototype, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct PackageDeclaration<'a> {
+pub struct PackageDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Option<Lifetime<'a>>,
-        PackageIdentifier<'a>,
-        Symbol<'a>,
-        Option<TimeunitsDeclaration<'a>>,
-        Vec<(Vec<AttributeInstance<'a>>, PackageItem<'a>)>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, PackageIdentifier<'a>)>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Option<Lifetime>,
+        PackageIdentifier,
+        Symbol,
+        Option<TimeunitsDeclaration>,
+        Vec<(Vec<AttributeInstance>, PackageItem)>,
+        Keyword,
+        Option<(Symbol, PackageIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TimeunitsDeclaration<'a> {
-    Timeunit(TimeunitsDeclarationTimeunit<'a>),
-    Timeprecision(TimeunitsDeclarationTimeprecision<'a>),
-    TimeunitTimeprecision(TimeunitsDeclarationTimeunitTimeprecision<'a>),
-    TimeprecisionTimeunit(TimeunitsDeclarationTimeprecisionTimeunit<'a>),
+pub enum TimeunitsDeclaration {
+    Timeunit(TimeunitsDeclarationTimeunit),
+    Timeprecision(TimeunitsDeclarationTimeprecision),
+    TimeunitTimeprecision(TimeunitsDeclarationTimeunitTimeprecision),
+    TimeprecisionTimeunit(TimeunitsDeclarationTimeprecisionTimeunit),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeunitsDeclarationTimeunit<'a> {
+pub struct TimeunitsDeclarationTimeunit {
     pub nodes: (
-        Keyword<'a>,
-        TimeLiteral<'a>,
-        Option<(Symbol<'a>, TimeLiteral<'a>)>,
-        Symbol<'a>,
+        Keyword,
+        TimeLiteral,
+        Option<(Symbol, TimeLiteral)>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeunitsDeclarationTimeprecision<'a> {
-    pub nodes: (Keyword<'a>, TimeLiteral<'a>, Symbol<'a>),
+pub struct TimeunitsDeclarationTimeprecision {
+    pub nodes: (Keyword, TimeLiteral, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeunitsDeclarationTimeunitTimeprecision<'a> {
+pub struct TimeunitsDeclarationTimeunitTimeprecision {
     pub nodes: (
-        Keyword<'a>,
-        TimeLiteral<'a>,
-        Symbol<'a>,
-        Keyword<'a>,
-        TimeLiteral<'a>,
-        Symbol<'a>,
+        Keyword,
+        TimeLiteral,
+        Symbol,
+        Keyword,
+        TimeLiteral,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeunitsDeclarationTimeprecisionTimeunit<'a> {
+pub struct TimeunitsDeclarationTimeprecisionTimeunit {
     pub nodes: (
-        Keyword<'a>,
-        TimeLiteral<'a>,
-        Symbol<'a>,
-        Keyword<'a>,
-        TimeLiteral<'a>,
-        Symbol<'a>,
+        Keyword,
+        TimeLiteral,
+        Symbol,
+        Keyword,
+        TimeLiteral,
+        Symbol,
     ),
 }
 
diff --git a/src/parser/specify_section/specify_block_declaration.rs b/src/parser/specify_section/specify_block_declaration.rs
index 7c2cab1..36f0601 100644
--- a/src/parser/specify_section/specify_block_declaration.rs
+++ b/src/parser/specify_section/specify_block_declaration.rs
@@ -8,27 +8,27 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct SpecifyBlock<'a> {
-    pub nodes: (Keyword<'a>, Vec<SpecifyItem<'a>>, Keyword<'a>),
+pub struct SpecifyBlock {
+    pub nodes: (Keyword, Vec<SpecifyItem>, Keyword),
 }
 
 #[derive(Debug, Node)]
-pub enum SpecifyItem<'a> {
-    SpecparamDeclaration(SpecparamDeclaration<'a>),
-    PulsestyleDeclaration(PulsestyleDeclaration<'a>),
-    ShowcancelledDeclaration(ShowcancelledDeclaration<'a>),
-    PathDeclaration(PathDeclaration<'a>),
-    SystemTimingCheck(SystemTimingCheck<'a>),
+pub enum SpecifyItem {
+    SpecparamDeclaration(SpecparamDeclaration),
+    PulsestyleDeclaration(PulsestyleDeclaration),
+    ShowcancelledDeclaration(ShowcancelledDeclaration),
+    PathDeclaration(PathDeclaration),
+    SystemTimingCheck(SystemTimingCheck),
 }
 
 #[derive(Debug, Node)]
-pub struct PulsestyleDeclaration<'a> {
-    pub nodes: (Keyword<'a>, ListOfPathOutputs<'a>, Symbol<'a>),
+pub struct PulsestyleDeclaration {
+    pub nodes: (Keyword, ListOfPathOutputs, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct ShowcancelledDeclaration<'a> {
-    pub nodes: (Keyword<'a>, ListOfPathOutputs<'a>, Symbol<'a>),
+pub struct ShowcancelledDeclaration {
+    pub nodes: (Keyword, ListOfPathOutputs, Symbol),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/specify_section/specify_block_terminals.rs b/src/parser/specify_section/specify_block_terminals.rs
index 9708b81..da66ce3 100644
--- a/src/parser/specify_section/specify_block_terminals.rs
+++ b/src/parser/specify_section/specify_block_terminals.rs
@@ -7,43 +7,37 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct SpecifyInputTerminalDescriptor<'a> {
-    pub nodes: (
-        InputIdentifier<'a>,
-        Option<Bracket<'a, ConstantRangeExpression<'a>>>,
-    ),
+pub struct SpecifyInputTerminalDescriptor {
+    pub nodes: (InputIdentifier, Option<Bracket<ConstantRangeExpression>>),
 }
 
 #[derive(Debug, Node)]
-pub struct SpecifyOutputTerminalDescriptor<'a> {
-    pub nodes: (
-        OutputIdentifier<'a>,
-        Option<Bracket<'a, ConstantRangeExpression<'a>>>,
-    ),
+pub struct SpecifyOutputTerminalDescriptor {
+    pub nodes: (OutputIdentifier, Option<Bracket<ConstantRangeExpression>>),
 }
 
 #[derive(Debug, Node)]
-pub enum InputIdentifier<'a> {
-    InputPortIdentifier(InputPortIdentifier<'a>),
-    InoutPortIdentifier(InoutPortIdentifier<'a>),
-    Interface(InputIdentifierInterface<'a>),
+pub enum InputIdentifier {
+    InputPortIdentifier(InputPortIdentifier),
+    InoutPortIdentifier(InoutPortIdentifier),
+    Interface(InputIdentifierInterface),
 }
 
 #[derive(Debug, Node)]
-pub struct InputIdentifierInterface<'a> {
-    pub nodes: (InterfaceIdentifier<'a>, Symbol<'a>, PortIdentifier<'a>),
+pub struct InputIdentifierInterface {
+    pub nodes: (InterfaceIdentifier, Symbol, PortIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub enum OutputIdentifier<'a> {
-    OutputPortIdentifier(OutputPortIdentifier<'a>),
-    InoutPortIdentifier(InoutPortIdentifier<'a>),
-    Interface(OutputIdentifierInterface<'a>),
+pub enum OutputIdentifier {
+    OutputPortIdentifier(OutputPortIdentifier),
+    InoutPortIdentifier(InoutPortIdentifier),
+    Interface(OutputIdentifierInterface),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputIdentifierInterface<'a> {
-    pub nodes: (InterfaceIdentifier<'a>, Symbol<'a>, PortIdentifier<'a>),
+pub struct OutputIdentifierInterface {
+    pub nodes: (InterfaceIdentifier, Symbol, PortIdentifier),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/specify_section/specify_path_declarations.rs b/src/parser/specify_section/specify_path_declarations.rs
index 50a8024..b3043d2 100644
--- a/src/parser/specify_section/specify_path_declarations.rs
+++ b/src/parser/specify_section/specify_path_declarations.rs
@@ -8,66 +8,60 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum PathDeclaration<'a> {
-    SimplePathDeclaration((SimplePathDeclaration<'a>, Symbol<'a>)),
-    EdgeSensitivePathDeclaration((EdgeSensitivePathDeclaration<'a>, Symbol<'a>)),
-    StateDependentPathDeclaration((StateDependentPathDeclaration<'a>, Symbol<'a>)),
+pub enum PathDeclaration {
+    SimplePathDeclaration((SimplePathDeclaration, Symbol)),
+    EdgeSensitivePathDeclaration((EdgeSensitivePathDeclaration, Symbol)),
+    StateDependentPathDeclaration((StateDependentPathDeclaration, Symbol)),
 }
 
 #[derive(Debug, Node)]
-pub enum SimplePathDeclaration<'a> {
-    Parallel(SimplePathDeclarationParallel<'a>),
-    Full(SimplePathDeclarationFull<'a>),
+pub enum SimplePathDeclaration {
+    Parallel(SimplePathDeclarationParallel),
+    Full(SimplePathDeclarationFull),
 }
 
 #[derive(Debug, Node)]
-pub struct SimplePathDeclarationParallel<'a> {
-    pub nodes: (ParallelPathDescription<'a>, Symbol<'a>, PathDelayValue<'a>),
+pub struct SimplePathDeclarationParallel {
+    pub nodes: (ParallelPathDescription, Symbol, PathDelayValue),
 }
 
 #[derive(Debug, Node)]
-pub struct SimplePathDeclarationFull<'a> {
-    pub nodes: (FullPathDescription<'a>, Symbol<'a>, PathDelayValue<'a>),
+pub struct SimplePathDeclarationFull {
+    pub nodes: (FullPathDescription, Symbol, PathDelayValue),
 }
 
 #[derive(Debug, Node)]
-pub struct ParallelPathDescription<'a> {
+pub struct ParallelPathDescription {
     pub nodes: (
-        Paren<
-            'a,
-            (
-                SpecifyInputTerminalDescriptor<'a>,
-                Option<PolarityOperator<'a>>,
-                Symbol<'a>,
-                SpecifyOutputTerminalDescriptor<'a>,
-            ),
-        >,
+        Paren<(
+            SpecifyInputTerminalDescriptor,
+            Option<PolarityOperator>,
+            Symbol,
+            SpecifyOutputTerminalDescriptor,
+        )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct FullPathDescription<'a> {
+pub struct FullPathDescription {
     pub nodes: (
-        Paren<
-            'a,
-            (
-                ListOfPathInputs<'a>,
-                Option<PolarityOperator<'a>>,
-                Symbol<'a>,
-                ListOfPathOutputs<'a>,
-            ),
-        >,
+        Paren<(
+            ListOfPathInputs,
+            Option<PolarityOperator>,
+            Symbol,
+            ListOfPathOutputs,
+        )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPathInputs<'a> {
-    pub nodes: (List<Symbol<'a>, SpecifyInputTerminalDescriptor<'a>>,),
+pub struct ListOfPathInputs {
+    pub nodes: (List<Symbol, SpecifyInputTerminalDescriptor>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPathOutputs<'a> {
-    pub nodes: (List<Symbol<'a>, SpecifyOutputTerminalDescriptor<'a>>,),
+pub struct ListOfPathOutputs {
+    pub nodes: (List<Symbol, SpecifyOutputTerminalDescriptor>,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/specify_section/specify_path_delays.rs b/src/parser/specify_section/specify_path_delays.rs
index 53cd322..0f59f14 100644
--- a/src/parser/specify_section/specify_path_delays.rs
+++ b/src/parser/specify_section/specify_path_delays.rs
@@ -8,147 +8,123 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum PathDelayValue<'a> {
-    ListOfPathDelayExpressions(ListOfPathDelayExpressions<'a>),
-    Paren(PathDelayValueParen<'a>),
+pub enum PathDelayValue {
+    ListOfPathDelayExpressions(ListOfPathDelayExpressions),
+    Paren(PathDelayValueParen),
 }
 
 #[derive(Debug, Node)]
-pub struct PathDelayValueParen<'a> {
-    pub nodes: (Paren<'a, ListOfPathDelayExpressions<'a>>,),
+pub struct PathDelayValueParen {
+    pub nodes: (Paren<ListOfPathDelayExpressions>,),
 }
 
 #[derive(Debug, Node)]
-pub struct ListOfPathDelayExpressions<'a> {
-    pub nodes: (List<Symbol<'a>, TPathDelayExpression<'a>>,),
+pub struct ListOfPathDelayExpressions {
+    pub nodes: (List<Symbol, TPathDelayExpression>,),
 }
 
 #[derive(Debug, Node)]
-pub struct TPathDelayExpression<'a> {
-    pub nodes: (PathDelayExpression<'a>,),
+pub struct TPathDelayExpression {
+    pub nodes: (PathDelayExpression,),
 }
 #[derive(Debug, Node)]
-pub struct PathDelayExpression<'a> {
-    pub nodes: (ConstantMintypmaxExpression<'a>,),
+pub struct PathDelayExpression {
+    pub nodes: (ConstantMintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub enum EdgeSensitivePathDeclaration<'a> {
-    Parallel(EdgeSensitivePathDeclarationParallel<'a>),
-    Full(EdgeSensitivePathDeclarationFull<'a>),
+pub enum EdgeSensitivePathDeclaration {
+    Parallel(EdgeSensitivePathDeclarationParallel),
+    Full(EdgeSensitivePathDeclarationFull),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeSensitivePathDeclarationParallel<'a> {
+pub struct EdgeSensitivePathDeclarationParallel {
+    pub nodes: (ParallelEdgeSensitivePathDescription, Symbol, PathDelayValue),
+}
+
+#[derive(Debug, Node)]
+pub struct EdgeSensitivePathDeclarationFull {
+    pub nodes: (FullEdgeSensitivePathDescription, Symbol, PathDelayValue),
+}
+
+#[derive(Debug, Node)]
+pub struct ParallelEdgeSensitivePathDescription {
     pub nodes: (
-        ParallelEdgeSensitivePathDescription<'a>,
-        Symbol<'a>,
-        PathDelayValue<'a>,
+        Paren<(
+            Option<EdgeIdentifier>,
+            SpecifyInputTerminalDescriptor,
+            Option<PolarityOperator>,
+            Symbol,
+            Paren<(
+                SpecifyOutputTerminalDescriptor,
+                Option<PolarityOperator>,
+                Symbol,
+                DataSourceExpression,
+            )>,
+        )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeSensitivePathDeclarationFull<'a> {
+pub struct FullEdgeSensitivePathDescription {
     pub nodes: (
-        FullEdgeSensitivePathDescription<'a>,
-        Symbol<'a>,
-        PathDelayValue<'a>,
+        Paren<(
+            Option<EdgeIdentifier>,
+            ListOfPathInputs,
+            Option<PolarityOperator>,
+            Symbol,
+            Paren<(
+                ListOfPathOutputs,
+                Option<PolarityOperator>,
+                Symbol,
+                DataSourceExpression,
+            )>,
+        )>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ParallelEdgeSensitivePathDescription<'a> {
+pub struct DataSourceExpression {
+    pub nodes: (Expression,),
+}
+
+#[derive(Debug, Node)]
+pub enum EdgeIdentifier {
+    Posedge(Keyword),
+    Negedge(Keyword),
+    Edge(Keyword),
+}
+
+#[derive(Debug, Node)]
+pub enum StateDependentPathDeclaration {
+    IfSimple(StateDependentPathDeclarationIfSimple),
+    IfEdgeSensitive(StateDependentPathDeclarationIfEdgeSensitive),
+    IfNone(StateDependentPathDeclarationIfNone),
+}
+
+#[derive(Debug, Node)]
+pub struct StateDependentPathDeclarationIfSimple {
+    pub nodes: (Keyword, Paren<ModulePathExpression>, SimplePathDeclaration),
+}
+
+#[derive(Debug, Node)]
+pub struct StateDependentPathDeclarationIfEdgeSensitive {
     pub nodes: (
-        Paren<
-            'a,
-            (
-                Option<EdgeIdentifier<'a>>,
-                SpecifyInputTerminalDescriptor<'a>,
-                Option<PolarityOperator<'a>>,
-                Symbol<'a>,
-                Paren<
-                    'a,
-                    (
-                        SpecifyOutputTerminalDescriptor<'a>,
-                        Option<PolarityOperator<'a>>,
-                        Symbol<'a>,
-                        DataSourceExpression<'a>,
-                    ),
-                >,
-            ),
-        >,
+        Keyword,
+        Paren<ModulePathExpression>,
+        EdgeSensitivePathDeclaration,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct FullEdgeSensitivePathDescription<'a> {
-    pub nodes: (
-        Paren<
-            'a,
-            (
-                Option<EdgeIdentifier<'a>>,
-                ListOfPathInputs<'a>,
-                Option<PolarityOperator<'a>>,
-                Symbol<'a>,
-                Paren<
-                    'a,
-                    (
-                        ListOfPathOutputs<'a>,
-                        Option<PolarityOperator<'a>>,
-                        Symbol<'a>,
-                        DataSourceExpression<'a>,
-                    ),
-                >,
-            ),
-        >,
-    ),
+pub struct StateDependentPathDeclarationIfNone {
+    pub nodes: (Keyword, SimplePathDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct DataSourceExpression<'a> {
-    pub nodes: (Expression<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub enum EdgeIdentifier<'a> {
-    Posedge(Keyword<'a>),
-    Negedge(Keyword<'a>),
-    Edge(Keyword<'a>),
-}
-
-#[derive(Debug, Node)]
-pub enum StateDependentPathDeclaration<'a> {
-    IfSimple(StateDependentPathDeclarationIfSimple<'a>),
-    IfEdgeSensitive(StateDependentPathDeclarationIfEdgeSensitive<'a>),
-    IfNone(StateDependentPathDeclarationIfNone<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct StateDependentPathDeclarationIfSimple<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ModulePathExpression<'a>>,
-        SimplePathDeclaration<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct StateDependentPathDeclarationIfEdgeSensitive<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Paren<'a, ModulePathExpression<'a>>,
-        EdgeSensitivePathDeclaration<'a>,
-    ),
-}
-
-#[derive(Debug, Node)]
-pub struct StateDependentPathDeclarationIfNone<'a> {
-    pub nodes: (Keyword<'a>, SimplePathDeclaration<'a>),
-}
-
-#[derive(Debug, Node)]
-pub struct PolarityOperator<'a> {
-    pub nodes: (Symbol<'a>,),
+pub struct PolarityOperator {
+    pub nodes: (Symbol,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/specify_section/system_timing_check_command_arguments.rs b/src/parser/specify_section/system_timing_check_command_arguments.rs
index 4dac4e6..9364ec9 100644
--- a/src/parser/specify_section/system_timing_check_command_arguments.rs
+++ b/src/parser/specify_section/system_timing_check_command_arguments.rs
@@ -7,91 +7,85 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct TimecheckCondition<'a> {
-    pub nodes: (MintypmaxExpression<'a>,),
+pub struct TimecheckCondition {
+    pub nodes: (MintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct ControlledReferenceEvent<'a> {
-    pub nodes: (ControlledTimingCheckEvent<'a>,),
+pub struct ControlledReferenceEvent {
+    pub nodes: (ControlledTimingCheckEvent,),
 }
 
 #[derive(Debug, Node)]
-pub struct DataEvent<'a> {
-    pub nodes: (TimingCheckEvent<'a>,),
+pub struct DataEvent {
+    pub nodes: (TimingCheckEvent,),
 }
 
 #[derive(Debug, Node)]
-pub enum DelayedData<'a> {
-    TerminalIdentifier(TerminalIdentifier<'a>),
-    WithMintypmax(DelayedDataWithMintypmax<'a>),
+pub enum DelayedData {
+    TerminalIdentifier(TerminalIdentifier),
+    WithMintypmax(DelayedDataWithMintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct DelayedDataWithMintypmax<'a> {
-    pub nodes: (
-        TerminalIdentifier<'a>,
-        Bracket<'a, ConstantMintypmaxExpression<'a>>,
-    ),
+pub struct DelayedDataWithMintypmax {
+    pub nodes: (TerminalIdentifier, Bracket<ConstantMintypmaxExpression>),
 }
 
 #[derive(Debug, Node)]
-pub enum DelayedReference<'a> {
-    TerminalIdentifier(TerminalIdentifier<'a>),
-    WithMintypmax(DelayedReferenceWithMintypmax<'a>),
+pub enum DelayedReference {
+    TerminalIdentifier(TerminalIdentifier),
+    WithMintypmax(DelayedReferenceWithMintypmax),
 }
 
 #[derive(Debug, Node)]
-pub struct DelayedReferenceWithMintypmax<'a> {
-    pub nodes: (
-        TerminalIdentifier<'a>,
-        Bracket<'a, ConstantMintypmaxExpression<'a>>,
-    ),
+pub struct DelayedReferenceWithMintypmax {
+    pub nodes: (TerminalIdentifier, Bracket<ConstantMintypmaxExpression>),
 }
 
 #[derive(Debug, Node)]
-pub struct EndEdgeOffset<'a> {
-    pub nodes: (MintypmaxExpression<'a>,),
+pub struct EndEdgeOffset {
+    pub nodes: (MintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct EventBasedFlag<'a> {
-    pub nodes: (ConstantExpression<'a>,),
+pub struct EventBasedFlag {
+    pub nodes: (ConstantExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct Notifier<'a> {
-    pub nodes: (VariableIdentifier<'a>,),
+pub struct Notifier {
+    pub nodes: (VariableIdentifier,),
 }
 
 #[derive(Debug, Node)]
-pub struct ReferenceEvent<'a> {
-    pub nodes: (TimingCheckEvent<'a>,),
+pub struct ReferenceEvent {
+    pub nodes: (TimingCheckEvent,),
 }
 
 #[derive(Debug, Node)]
-pub struct RemainActiveFlag<'a> {
-    pub nodes: (ConstantMintypmaxExpression<'a>,),
+pub struct RemainActiveFlag {
+    pub nodes: (ConstantMintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct TimestampCondition<'a> {
-    pub nodes: (MintypmaxExpression<'a>,),
+pub struct TimestampCondition {
+    pub nodes: (MintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct StartEdgeOffset<'a> {
-    pub nodes: (MintypmaxExpression<'a>,),
+pub struct StartEdgeOffset {
+    pub nodes: (MintypmaxExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct Threshold<'a> {
-    pub nodes: (ConstantExpression<'a>,),
+pub struct Threshold {
+    pub nodes: (ConstantExpression,),
 }
 
 #[derive(Debug, Node)]
-pub struct TimingCheckLimit<'a> {
-    pub nodes: (Expression<'a>,),
+pub struct TimingCheckLimit {
+    pub nodes: (Expression,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/specify_section/system_timing_check_commands.rs b/src/parser/specify_section/system_timing_check_commands.rs
index cd7024f..bab6582 100644
--- a/src/parser/specify_section/system_timing_check_commands.rs
+++ b/src/parser/specify_section/system_timing_check_commands.rs
@@ -8,300 +8,264 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum SystemTimingCheck<'a> {
-    SetupTimingCheck(SetupTimingCheck<'a>),
-    HoldTimingCheck(HoldTimingCheck<'a>),
-    SetupholdTimingCheck(SetupholdTimingCheck<'a>),
-    RecoveryTimingCheck(RecoveryTimingCheck<'a>),
-    RemovalTimingCheck(RemovalTimingCheck<'a>),
-    RecremTimingCheck(RecremTimingCheck<'a>),
-    SkewTimingCheck(SkewTimingCheck<'a>),
-    TimeskewTimingCheck(TimeskewTimingCheck<'a>),
-    FullskewTimingCheck(FullskewTimingCheck<'a>),
-    PeriodTimingCheck(PeriodTimingCheck<'a>),
-    WidthTimingCheck(WidthTimingCheck<'a>),
-    NochargeTimingCheck(NochargeTimingCheck<'a>),
+pub enum SystemTimingCheck {
+    SetupTimingCheck(SetupTimingCheck),
+    HoldTimingCheck(HoldTimingCheck),
+    SetupholdTimingCheck(SetupholdTimingCheck),
+    RecoveryTimingCheck(RecoveryTimingCheck),
+    RemovalTimingCheck(RemovalTimingCheck),
+    RecremTimingCheck(RecremTimingCheck),
+    SkewTimingCheck(SkewTimingCheck),
+    TimeskewTimingCheck(TimeskewTimingCheck),
+    FullskewTimingCheck(FullskewTimingCheck),
+    PeriodTimingCheck(PeriodTimingCheck),
+    WidthTimingCheck(WidthTimingCheck),
+    NochargeTimingCheck(NochargeTimingCheck),
 }
 
 #[derive(Debug, Node)]
-pub struct SetupTimingCheck<'a> {
+pub struct SetupTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                DataEvent<'a>,
-                Symbol<'a>,
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            DataEvent,
+            Symbol,
+            ReferenceEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct HoldTimingCheck<'a> {
+pub struct HoldTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SetupholdTimingCheck<'a> {
+pub struct SetupholdTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Symbol,
+            TimingCheckLimit,
+            Option<(
+                Symbol,
+                Option<Notifier>,
                 Option<(
-                    Symbol<'a>,
-                    Option<Notifier<'a>>,
+                    Symbol,
+                    Option<TimestampCondition>,
                     Option<(
-                        Symbol<'a>,
-                        Option<TimestampCondition<'a>>,
+                        Symbol,
+                        Option<TimecheckCondition>,
                         Option<(
-                            Symbol<'a>,
-                            Option<TimecheckCondition<'a>>,
-                            Option<(
-                                Symbol<'a>,
-                                Option<DelayedReference<'a>>,
-                                Option<(Symbol<'a>, Option<DelayedData<'a>>)>,
-                            )>,
+                            Symbol,
+                            Option<DelayedReference>,
+                            Option<(Symbol, Option<DelayedData>)>,
                         )>,
                     )>,
                 )>,
-            ),
-        >,
-        Symbol<'a>,
+            )>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RecoveryTimingCheck<'a> {
+pub struct RecoveryTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RemovalTimingCheck<'a> {
+pub struct RemovalTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct RecremTimingCheck<'a> {
+pub struct RecremTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Symbol,
+            TimingCheckLimit,
+            Option<(
+                Symbol,
+                Option<Notifier>,
                 Option<(
-                    Symbol<'a>,
-                    Option<Notifier<'a>>,
+                    Symbol,
+                    Option<TimestampCondition>,
                     Option<(
-                        Symbol<'a>,
-                        Option<TimestampCondition<'a>>,
+                        Symbol,
+                        Option<TimecheckCondition>,
                         Option<(
-                            Symbol<'a>,
-                            Option<TimecheckCondition<'a>>,
-                            Option<(
-                                Symbol<'a>,
-                                Option<DelayedReference<'a>>,
-                                Option<(Symbol<'a>, Option<DelayedData<'a>>)>,
-                            )>,
+                            Symbol,
+                            Option<DelayedReference>,
+                            Option<(Symbol, Option<DelayedData>)>,
                         )>,
                     )>,
                 )>,
-            ),
-        >,
-        Symbol<'a>,
+            )>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct SkewTimingCheck<'a> {
+pub struct SkewTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct TimeskewTimingCheck<'a> {
+pub struct TimeskewTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(
+                Symbol,
+                Option<Notifier>,
                 Option<(
-                    Symbol<'a>,
-                    Option<Notifier<'a>>,
-                    Option<(
-                        Symbol<'a>,
-                        Option<EventBasedFlag<'a>>,
-                        Option<(Symbol<'a>, Option<RemainActiveFlag<'a>>)>,
-                    )>,
+                    Symbol,
+                    Option<EventBasedFlag>,
+                    Option<(Symbol, Option<RemainActiveFlag>)>,
                 )>,
-            ),
-        >,
-        Symbol<'a>,
+            )>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct FullskewTimingCheck<'a> {
+pub struct FullskewTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            TimingCheckLimit,
+            Symbol,
+            TimingCheckLimit,
+            Option<(
+                Symbol,
+                Option<Notifier>,
                 Option<(
-                    Symbol<'a>,
-                    Option<Notifier<'a>>,
-                    Option<(
-                        Symbol<'a>,
-                        Option<EventBasedFlag<'a>>,
-                        Option<(Symbol<'a>, Option<RemainActiveFlag<'a>>)>,
-                    )>,
+                    Symbol,
+                    Option<EventBasedFlag>,
+                    Option<(Symbol, Option<RemainActiveFlag>)>,
                 )>,
-            ),
-        >,
-        Symbol<'a>,
+            )>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct PeriodTimingCheck<'a> {
+pub struct PeriodTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ControlledReferenceEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ControlledReferenceEvent,
+            Symbol,
+            TimingCheckLimit,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct WidthTimingCheck<'a> {
+pub struct WidthTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ControlledReferenceEvent<'a>,
-                Symbol<'a>,
-                TimingCheckLimit<'a>,
-                Symbol<'a>,
-                Threshold<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ControlledReferenceEvent,
+            Symbol,
+            TimingCheckLimit,
+            Symbol,
+            Threshold,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct NochargeTimingCheck<'a> {
+pub struct NochargeTimingCheck {
     pub nodes: (
-        Keyword<'a>,
-        Paren<
-            'a,
-            (
-                ReferenceEvent<'a>,
-                Symbol<'a>,
-                DataEvent<'a>,
-                Symbol<'a>,
-                StartEdgeOffset<'a>,
-                Symbol<'a>,
-                EndEdgeOffset<'a>,
-                Option<(Symbol<'a>, Option<Notifier<'a>>)>,
-            ),
-        >,
-        Symbol<'a>,
+        Keyword,
+        Paren<(
+            ReferenceEvent,
+            Symbol,
+            DataEvent,
+            Symbol,
+            StartEdgeOffset,
+            Symbol,
+            EndEdgeOffset,
+            Option<(Symbol, Option<Notifier>)>,
+        )>,
+        Symbol,
     ),
 }
 
diff --git a/src/parser/specify_section/system_timing_check_event_definitions.rs b/src/parser/specify_section/system_timing_check_event_definitions.rs
index 0ca5169..f155987 100644
--- a/src/parser/specify_section/system_timing_check_event_definitions.rs
+++ b/src/parser/specify_section/system_timing_check_event_definitions.rs
@@ -8,81 +8,78 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct TimingCheckEvent<'a> {
+pub struct TimingCheckEvent {
     pub nodes: (
-        Option<TimingCheckEventControl<'a>>,
-        SpecifyTerminalDescriptor<'a>,
-        Option<(Symbol<'a>, TimingCheckCondition<'a>)>,
+        Option<TimingCheckEventControl>,
+        SpecifyTerminalDescriptor,
+        Option<(Symbol, TimingCheckCondition)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct ControlledTimingCheckEvent<'a> {
+pub struct ControlledTimingCheckEvent {
     pub nodes: (
-        TimingCheckEventControl<'a>,
-        SpecifyTerminalDescriptor<'a>,
-        Option<(Symbol<'a>, TimingCheckCondition<'a>)>,
+        TimingCheckEventControl,
+        SpecifyTerminalDescriptor,
+        Option<(Symbol, TimingCheckCondition)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum TimingCheckEventControl<'a> {
-    Posedge(Keyword<'a>),
-    Negedge(Keyword<'a>),
-    Edge(Keyword<'a>),
-    EdgeControlSpecifier(EdgeControlSpecifier<'a>),
+pub enum TimingCheckEventControl {
+    Posedge(Keyword),
+    Negedge(Keyword),
+    Edge(Keyword),
+    EdgeControlSpecifier(EdgeControlSpecifier),
 }
 
 #[derive(Debug, Node)]
-pub enum SpecifyTerminalDescriptor<'a> {
-    SpecifyInputTerminalDescriptor(SpecifyInputTerminalDescriptor<'a>),
-    SpecifyOutputTerminalDescriptor(SpecifyOutputTerminalDescriptor<'a>),
+pub enum SpecifyTerminalDescriptor {
+    SpecifyInputTerminalDescriptor(SpecifyInputTerminalDescriptor),
+    SpecifyOutputTerminalDescriptor(SpecifyOutputTerminalDescriptor),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeControlSpecifier<'a> {
-    pub nodes: (
-        Keyword<'a>,
-        Bracket<'a, List<Symbol<'a>, EdgeDescriptor<'a>>>,
-    ),
+pub struct EdgeControlSpecifier {
+    pub nodes: (Keyword, Bracket<List<Symbol, EdgeDescriptor>>),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeDescriptor<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct EdgeDescriptor {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub enum TimingCheckCondition<'a> {
-    ScalarTimingCheckCondition(ScalarTimingCheckCondition<'a>),
-    Paren(TimingCheckConditionParen<'a>),
+pub enum TimingCheckCondition {
+    ScalarTimingCheckCondition(ScalarTimingCheckCondition),
+    Paren(TimingCheckConditionParen),
 }
 
 #[derive(Debug, Node)]
-pub struct TimingCheckConditionParen<'a> {
-    pub nodes: (Paren<'a, ScalarTimingCheckCondition<'a>>,),
+pub struct TimingCheckConditionParen {
+    pub nodes: (Paren<ScalarTimingCheckCondition>,),
 }
 
 #[derive(Debug, Node)]
-pub enum ScalarTimingCheckCondition<'a> {
-    Expression(Expression<'a>),
-    Unary(ScalarTimingCheckConditionUnary<'a>),
-    Binary(ScalarTimingCheckConditionBinary<'a>),
+pub enum ScalarTimingCheckCondition {
+    Expression(Expression),
+    Unary(ScalarTimingCheckConditionUnary),
+    Binary(ScalarTimingCheckConditionBinary),
 }
 
 #[derive(Debug, Node)]
-pub struct ScalarTimingCheckConditionUnary<'a> {
-    pub nodes: (Symbol<'a>, Expression<'a>),
+pub struct ScalarTimingCheckConditionUnary {
+    pub nodes: (Symbol, Expression),
 }
 
 #[derive(Debug, Node)]
-pub struct ScalarTimingCheckConditionBinary<'a> {
-    pub nodes: (Expression<'a>, Symbol<'a>, ScalarConstant<'a>),
+pub struct ScalarTimingCheckConditionBinary {
+    pub nodes: (Expression, Symbol, ScalarConstant),
 }
 
 #[derive(Debug, Node)]
-pub struct ScalarConstant<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct ScalarConstant {
+    pub nodes: (Keyword,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/udp_declaration_and_instantiation/udp_body.rs b/src/parser/udp_declaration_and_instantiation/udp_body.rs
index cd3a763..3e21325 100644
--- a/src/parser/udp_declaration_and_instantiation/udp_body.rs
+++ b/src/parser/udp_declaration_and_instantiation/udp_body.rs
@@ -9,120 +9,110 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub enum UdpBody<'a> {
-    CombinationalBody(CombinationalBody<'a>),
-    SequentialBody(SequentialBody<'a>),
+pub enum UdpBody {
+    CombinationalBody(CombinationalBody),
+    SequentialBody(SequentialBody),
 }
 
 #[derive(Debug, Node)]
-pub struct CombinationalBody<'a> {
+pub struct CombinationalBody {
     pub nodes: (
-        Keyword<'a>,
-        CombinationalEntry<'a>,
-        Vec<CombinationalEntry<'a>>,
-        Keyword<'a>,
+        Keyword,
+        CombinationalEntry,
+        Vec<CombinationalEntry>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct CombinationalEntry<'a> {
-    pub nodes: (LevelInputList<'a>, Symbol<'a>, OutputSymbol<'a>, Symbol<'a>),
+pub struct CombinationalEntry {
+    pub nodes: (LevelInputList, Symbol, OutputSymbol, Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct SequentialBody<'a> {
+pub struct SequentialBody {
     pub nodes: (
-        Option<UdpInitialStatement<'a>>,
-        Keyword<'a>,
-        SequentialEntry<'a>,
-        Vec<SequentialEntry<'a>>,
-        Keyword<'a>,
+        Option<UdpInitialStatement>,
+        Keyword,
+        SequentialEntry,
+        Vec<SequentialEntry>,
+        Keyword,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpInitialStatement<'a> {
+pub struct UdpInitialStatement {
+    pub nodes: (Keyword, OutputPortIdentifier, Symbol, InitVal, Symbol),
+}
+
+#[derive(Debug, Node)]
+pub struct InitVal {
+    pub nodes: (Keyword,),
+}
+
+#[derive(Debug, Node)]
+pub struct SequentialEntry {
     pub nodes: (
-        Keyword<'a>,
-        OutputPortIdentifier<'a>,
-        Symbol<'a>,
-        InitVal<'a>,
-        Symbol<'a>,
+        SeqInputList,
+        Symbol,
+        CurrentState,
+        Symbol,
+        NextState,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct InitVal<'a> {
-    pub nodes: (Keyword<'a>,),
+pub enum SeqInputList {
+    LevelInputList(LevelInputList),
+    EdgeInputList(EdgeInputList),
 }
 
 #[derive(Debug, Node)]
-pub struct SequentialEntry<'a> {
-    pub nodes: (
-        SeqInputList<'a>,
-        Symbol<'a>,
-        CurrentState<'a>,
-        Symbol<'a>,
-        NextState<'a>,
-        Symbol<'a>,
-    ),
+pub struct LevelInputList {
+    pub nodes: (LevelSymbol, Vec<LevelSymbol>),
 }
 
 #[derive(Debug, Node)]
-pub enum SeqInputList<'a> {
-    LevelInputList(LevelInputList<'a>),
-    EdgeInputList(EdgeInputList<'a>),
+pub struct EdgeInputList {
+    pub nodes: (Vec<LevelSymbol>, EdgeIndicator, Vec<LevelSymbol>),
 }
 
 #[derive(Debug, Node)]
-pub struct LevelInputList<'a> {
-    pub nodes: (LevelSymbol<'a>, Vec<LevelSymbol<'a>>),
+pub enum EdgeIndicator {
+    Paren(EdgeIndicatorParen),
+    EdgeSymbol(EdgeSymbol),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeInputList<'a> {
-    pub nodes: (
-        Vec<LevelSymbol<'a>>,
-        EdgeIndicator<'a>,
-        Vec<LevelSymbol<'a>>,
-    ),
+pub struct EdgeIndicatorParen {
+    pub nodes: (Paren<(LevelSymbol, LevelSymbol)>,),
 }
 
 #[derive(Debug, Node)]
-pub enum EdgeIndicator<'a> {
-    Paren(EdgeIndicatorParen<'a>),
-    EdgeSymbol(EdgeSymbol<'a>),
+pub struct CurrentState {
+    pub nodes: (LevelSymbol,),
 }
 
 #[derive(Debug, Node)]
-pub struct EdgeIndicatorParen<'a> {
-    pub nodes: (Paren<'a, (LevelSymbol<'a>, LevelSymbol<'a>)>,),
+pub enum NextState {
+    OutputSymbol(OutputSymbol),
+    Minus(Symbol),
 }
 
 #[derive(Debug, Node)]
-pub struct CurrentState<'a> {
-    pub nodes: (LevelSymbol<'a>,),
+pub struct OutputSymbol {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub enum NextState<'a> {
-    OutputSymbol(OutputSymbol<'a>),
-    Minus(Symbol<'a>),
+pub struct LevelSymbol {
+    pub nodes: (Keyword,),
 }
 
 #[derive(Debug, Node)]
-pub struct OutputSymbol<'a> {
-    pub nodes: (Keyword<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct LevelSymbol<'a> {
-    pub nodes: (Keyword<'a>,),
-}
-
-#[derive(Debug, Node)]
-pub struct EdgeSymbol<'a> {
-    pub nodes: (Keyword<'a>,),
+pub struct EdgeSymbol {
+    pub nodes: (Keyword,),
 }
 
 // -----------------------------------------------------------------------------
diff --git a/src/parser/udp_declaration_and_instantiation/udp_declaration.rs b/src/parser/udp_declaration_and_instantiation/udp_declaration.rs
index 3538fda..a7f5c9e 100644
--- a/src/parser/udp_declaration_and_instantiation/udp_declaration.rs
+++ b/src/parser/udp_declaration_and_instantiation/udp_declaration.rs
@@ -9,80 +9,80 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct UdpNonansiDeclaration<'a> {
+pub struct UdpNonansiDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        UdpIdentifier<'a>,
-        Paren<'a, UdpPortList<'a>>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        UdpIdentifier,
+        Paren<UdpPortList>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpAnsiDeclaration<'a> {
+pub struct UdpAnsiDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        UdpIdentifier<'a>,
-        Paren<'a, UdpDeclarationPortList<'a>>,
-        Symbol<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        UdpIdentifier,
+        Paren<UdpDeclarationPortList>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum UdpDeclaration<'a> {
-    Nonansi(UdpDeclarationNonansi<'a>),
-    Ansi(UdpDeclarationAnsi<'a>),
-    ExternNonansi(UdpDeclarationExternNonansi<'a>),
-    ExternAnsi(UdpDeclarationExternAnsi<'a>),
-    Wildcard(UdpDeclarationWildcard<'a>),
+pub enum UdpDeclaration {
+    Nonansi(UdpDeclarationNonansi),
+    Ansi(UdpDeclarationAnsi),
+    ExternNonansi(UdpDeclarationExternNonansi),
+    ExternAnsi(UdpDeclarationExternAnsi),
+    Wildcard(UdpDeclarationWildcard),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationNonansi<'a> {
+pub struct UdpDeclarationNonansi {
     pub nodes: (
-        UdpNonansiDeclaration<'a>,
-        UdpPortDeclaration<'a>,
-        Vec<UdpPortDeclaration<'a>>,
-        UdpBody<'a>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, UdpIdentifier<'a>)>,
+        UdpNonansiDeclaration,
+        UdpPortDeclaration,
+        Vec<UdpPortDeclaration>,
+        UdpBody,
+        Keyword,
+        Option<(Symbol, UdpIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationAnsi<'a> {
+pub struct UdpDeclarationAnsi {
     pub nodes: (
-        UdpAnsiDeclaration<'a>,
-        UdpBody<'a>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, UdpIdentifier<'a>)>,
+        UdpAnsiDeclaration,
+        UdpBody,
+        Keyword,
+        Option<(Symbol, UdpIdentifier)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationExternNonansi<'a> {
-    pub nodes: (Keyword<'a>, UdpNonansiDeclaration<'a>),
+pub struct UdpDeclarationExternNonansi {
+    pub nodes: (Keyword, UdpNonansiDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationExternAnsi<'a> {
-    pub nodes: (Keyword<'a>, UdpAnsiDeclaration<'a>),
+pub struct UdpDeclarationExternAnsi {
+    pub nodes: (Keyword, UdpAnsiDeclaration),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationWildcard<'a> {
+pub struct UdpDeclarationWildcard {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        UdpIdentifier<'a>,
-        Paren<'a, Symbol<'a>>,
-        Symbol<'a>,
-        Vec<UdpPortDeclaration<'a>>,
-        UdpBody<'a>,
-        Keyword<'a>,
-        Option<(Symbol<'a>, UdpIdentifier<'a>)>,
+        Vec<AttributeInstance>,
+        Keyword,
+        UdpIdentifier,
+        Paren<Symbol>,
+        Symbol,
+        Vec<UdpPortDeclaration>,
+        UdpBody,
+        Keyword,
+        Option<(Symbol, UdpIdentifier)>,
     ),
 }
 
diff --git a/src/parser/udp_declaration_and_instantiation/udp_instantiation.rs b/src/parser/udp_declaration_and_instantiation/udp_instantiation.rs
index 41950e4..37003c9 100644
--- a/src/parser/udp_declaration_and_instantiation/udp_instantiation.rs
+++ b/src/parser/udp_declaration_and_instantiation/udp_instantiation.rs
@@ -8,29 +8,26 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct UdpInstantiation<'a> {
+pub struct UdpInstantiation {
     pub nodes: (
-        UdpIdentifier<'a>,
-        Option<DriveStrength<'a>>,
-        Option<Delay2<'a>>,
-        List<Symbol<'a>, UdpInstance<'a>>,
-        Symbol<'a>,
+        UdpIdentifier,
+        Option<DriveStrength>,
+        Option<Delay2>,
+        List<Symbol, UdpInstance>,
+        Symbol,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpInstance<'a> {
+pub struct UdpInstance {
     pub nodes: (
-        Option<NameOfInstance<'a>>,
-        Paren<
-            'a,
-            (
-                OutputTerminal<'a>,
-                Symbol<'a>,
-                InputTerminal<'a>,
-                Vec<(Symbol<'a>, InputTerminal<'a>)>,
-            ),
-        >,
+        Option<NameOfInstance>,
+        Paren<(
+            OutputTerminal,
+            Symbol,
+            InputTerminal,
+            Vec<(Symbol, InputTerminal)>,
+        )>,
     ),
 }
 
diff --git a/src/parser/udp_declaration_and_instantiation/udp_ports.rs b/src/parser/udp_declaration_and_instantiation/udp_ports.rs
index fdb466c..5c84615 100644
--- a/src/parser/udp_declaration_and_instantiation/udp_ports.rs
+++ b/src/parser/udp_declaration_and_instantiation/udp_ports.rs
@@ -9,67 +9,67 @@ use nom::IResult;
 // -----------------------------------------------------------------------------
 
 #[derive(Debug, Node)]
-pub struct UdpPortList<'a> {
+pub struct UdpPortList {
     pub nodes: (
-        OutputPortIdentifier<'a>,
-        Symbol<'a>,
-        List<Symbol<'a>, InputPortIdentifier<'a>>,
+        OutputPortIdentifier,
+        Symbol,
+        List<Symbol, InputPortIdentifier>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpDeclarationPortList<'a> {
+pub struct UdpDeclarationPortList {
     pub nodes: (
-        UdpOutputDeclaration<'a>,
-        Symbol<'a>,
-        List<Symbol<'a>, UdpInputDeclaration<'a>>,
+        UdpOutputDeclaration,
+        Symbol,
+        List<Symbol, UdpInputDeclaration>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub enum UdpPortDeclaration<'a> {
-    UdpOutputDeclaration((UdpOutputDeclaration<'a>, Symbol<'a>)),
-    UdpInputDeclaration((UdpInputDeclaration<'a>, Symbol<'a>)),
-    UdpRegDeclaration((UdpRegDeclaration<'a>, Symbol<'a>)),
+pub enum UdpPortDeclaration {
+    UdpOutputDeclaration((UdpOutputDeclaration, Symbol)),
+    UdpInputDeclaration((UdpInputDeclaration, Symbol)),
+    UdpRegDeclaration((UdpRegDeclaration, Symbol)),
 }
 
 #[derive(Debug, Node)]
-pub enum UdpOutputDeclaration<'a> {
-    Nonreg(UdpOutputDeclarationNonreg<'a>),
-    Reg(UdpOutputDeclarationReg<'a>),
+pub enum UdpOutputDeclaration {
+    Nonreg(UdpOutputDeclarationNonreg),
+    Reg(UdpOutputDeclarationReg),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpOutputDeclarationNonreg<'a> {
-    pub nodes: (Vec<AttributeInstance<'a>>, Keyword<'a>, PortIdentifier<'a>),
+pub struct UdpOutputDeclarationNonreg {
+    pub nodes: (Vec<AttributeInstance>, Keyword, PortIdentifier),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpOutputDeclarationReg<'a> {
+pub struct UdpOutputDeclarationReg {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        Keyword<'a>,
-        PortIdentifier<'a>,
-        Option<(Symbol<'a>, ConstantExpression<'a>)>,
+        Vec<AttributeInstance>,
+        Keyword,
+        Keyword,
+        PortIdentifier,
+        Option<(Symbol, ConstantExpression)>,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpInputDeclaration<'a> {
+pub struct UdpInputDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        ListOfUdpPortIdentifiers<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        ListOfUdpPortIdentifiers,
     ),
 }
 
 #[derive(Debug, Node)]
-pub struct UdpRegDeclaration<'a> {
+pub struct UdpRegDeclaration {
     pub nodes: (
-        Vec<AttributeInstance<'a>>,
-        Keyword<'a>,
-        VariableIdentifier<'a>,
+        Vec<AttributeInstance>,
+        Keyword,
+        VariableIdentifier,
     ),
 }
 
diff --git a/src/parser/utils.rs b/src/parser/utils.rs
index 1d18d23..2b5cb3b 100644
--- a/src/parser/utils.rs
+++ b/src/parser/utils.rs
@@ -262,39 +262,39 @@ const KEYWORDS: &[&str] = &[
 ];
 
 #[derive(Debug, Node)]
-pub struct Symbol<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct Symbol {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub struct Keyword<'a> {
-    pub nodes: (Span<'a>, Vec<WhiteSpace<'a>>),
+pub struct Keyword {
+    pub nodes: (Locate, Vec<WhiteSpace>),
 }
 
 #[derive(Debug, Node)]
-pub enum WhiteSpace<'a> {
-    Space(Span<'a>),
-    Comment(Comment<'a>),
+pub enum WhiteSpace {
+    Space(Locate),
+    Comment(Comment),
 }
 
 #[derive(Debug)]
-pub struct Paren<'a, T: 'a> {
-    pub nodes: (Symbol<'a>, T, Symbol<'a>),
+pub struct Paren<T> {
+    pub nodes: (Symbol, T, Symbol),
 }
 
 #[derive(Debug)]
-pub struct Brace<'a, T: 'a> {
-    pub nodes: (Symbol<'a>, T, Symbol<'a>),
+pub struct Brace<T> {
+    pub nodes: (Symbol, T, Symbol),
 }
 
 #[derive(Debug)]
-pub struct Bracket<'a, T: 'a> {
-    pub nodes: (Symbol<'a>, T, Symbol<'a>),
+pub struct Bracket<T> {
+    pub nodes: (Symbol, T, Symbol),
 }
 
 #[derive(Debug)]
-pub struct ApostropheBrace<'a, T: 'a> {
-    pub nodes: (Symbol<'a>, T, Symbol<'a>),
+pub struct ApostropheBrace<T> {
+    pub nodes: (Symbol, T, Symbol),
 }
 
 #[derive(Debug)]
@@ -304,7 +304,7 @@ pub struct List<T, U> {
 
 // -----------------------------------------------------------------------------
 
-pub fn ws<'a, O, F>(f: F) -> impl Fn(Span<'a>) -> IResult<Span<'a>, (O, Vec<WhiteSpace<'a>>)>
+pub fn ws<'a, O, F>(f: F) -> impl Fn(Span<'a>) -> IResult<Span<'a>, (O, Vec<WhiteSpace>)>
 where
     F: Fn(Span<'a>) -> IResult<Span<'a>, O>,
 {
@@ -315,22 +315,28 @@ where
     }
 }
 
-pub fn symbol<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>, Symbol<'a>> {
+pub fn symbol<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>, Symbol> {
     move |s: Span<'a>| {
         #[cfg(feature = "trace")]
         let s = trace(s, &format!("symbol(\"{}\")", t));
-        let (s, x) = map(ws(tag(t.clone())), |x| Symbol { nodes: x })(s)?;
+        let (s, x) = map(ws(map(tag(t.clone()), |x: Span| x.into())), |x| Symbol {
+            nodes: x,
+        })(s)?;
         Ok((clear_recursive_flags(s), x))
     }
 }
 
-pub fn keyword<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>, Keyword<'a>> {
+pub fn keyword<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>, Keyword> {
     move |s: Span<'a>| {
         #[cfg(feature = "trace")]
         let s = trace(s, &format!("keyword(\"{}\")", t));
-        let (s, x) = map(ws(terminated(tag(t.clone()), peek(none_of(AZ09_)))), |x| {
-            Keyword { nodes: x }
-        })(s)?;
+        let (s, x) = map(
+            ws(terminated(
+                map(tag(t.clone()), |x: Span| x.into()),
+                peek(none_of(AZ09_)),
+            )),
+            |x| Keyword { nodes: x },
+        )(s)?;
         Ok((clear_recursive_flags(s), x))
     }
 }
@@ -467,7 +473,7 @@ where
 #[parser]
 pub fn white_space(s: Span) -> IResult<Span, WhiteSpace> {
     alt((
-        map(multispace1, |x| WhiteSpace::Space(x)),
+        map(multispace1, |x: Span| WhiteSpace::Space(x.into())),
         map(comment, |x| WhiteSpace::Comment(x)),
     ))(s)
 }
diff --git a/sv-parser-macro/src/lib.rs b/sv-parser-macro/src/lib.rs
index ea884df..0308203 100644
--- a/sv-parser-macro/src/lib.rs
+++ b/sv-parser-macro/src/lib.rs
@@ -52,24 +52,24 @@ fn impl_node(ast: &DeriveInput) -> TokenStream {
     };
 
     let gen = quote! {
-        impl<'a> Node<'a> for #name<'a> {
+        impl<'a> Node<'a> for #name {
             fn next(&'a self) -> AnyNodes<'a> {
                 #next
             }
         }
 
-        impl<'a> From<&'a #name<'a>> for AnyNodes<'a>  {
-            fn from(x: &'a #name<'a>) -> Self {
+        impl<'a> From<&'a #name> for AnyNodes<'a>  {
+            fn from(x: &'a #name) -> Self {
                 vec![AnyNode::#name(x)].into()
             }
         }
 
-        impl<'a> IntoIterator for &'a #name<'a> {
+        impl<'a> IntoIterator for &'a #name {
             type Item = AnyNode<'a>;
             type IntoIter = Iter<'a>;
 
             fn into_iter(self) -> Self::IntoIter {
-                let nodes: AnyNodes<'a> = self.into();
+                let nodes: AnyNodes = self.into();
                 Iter { next: nodes }
             }
         }