diff --git a/sv-parser-parser/Cargo.toml b/sv-parser-parser/Cargo.toml
index 199e5c5..ce3453e 100644
--- a/sv-parser-parser/Cargo.toml
+++ b/sv-parser-parser/Cargo.toml
@@ -6,12 +6,13 @@ edition = "2018"
 
 [features]
 default = []
-trace = ["sv-parser-syntaxtree/trace"]
+trace = []
 
 [dependencies]
 nom                  = "5.0.0"
+nom_locate           = { path = "../../nom_locate" }
 nom-packrat          = "0.1.17"
 nom-recursive        = { path = "../../nom-recursive/nom-recursive" }
 str-concat           = "*"
-sv-parser-syntaxtree = { path = "../sv-parser-syntaxtree" }
 sv-parser-macros     = { path = "../sv-parser-macros" }
+sv-parser-syntaxtree = { path = "../sv-parser-syntaxtree" }
diff --git a/sv-parser-parser/src/expressions/numbers.rs b/sv-parser-parser/src/expressions/numbers.rs
index 5dcb95b..a3c24c2 100644
--- a/sv-parser-parser/src/expressions/numbers.rs
+++ b/sv-parser-parser/src/expressions/numbers.rs
@@ -118,7 +118,7 @@ pub(crate) fn non_zero_unsigned_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -150,7 +150,7 @@ pub(crate) fn real_number_floating(s: Span) -> IResult<Span, RealNumber> {
 pub(crate) fn fixed_point_number(s: Span) -> IResult<Span, FixedPointNumber> {
     let (s, a) = unsigned_number(s)?;
     let (s, b) = map(tag("."), |x: Span| Symbol {
-        nodes: (x.into(), vec![]),
+        nodes: (into_locate(x), vec![]),
     })(s)?;
     let (s, c) = unsigned_number(s)?;
     Ok((s, FixedPointNumber { nodes: (a, b, c) }))
@@ -174,7 +174,7 @@ pub(crate) fn unsigned_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), digit1)), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -189,7 +189,7 @@ pub(crate) fn binary_value_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), is_a("01xXzZ?"))), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -204,7 +204,7 @@ pub(crate) fn octal_value_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), is_a("01234567xXzZ?"))), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -221,7 +221,7 @@ pub(crate) fn hex_value_impl(s: Span) -> IResult<Span, Locate> {
         a,
         |acc, item| concat(acc, item).unwrap(),
     )(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -233,7 +233,7 @@ pub(crate) fn decimal_base(s: Span) -> IResult<Span, DecimalBase> {
 #[parser]
 pub(crate) 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()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -245,7 +245,7 @@ pub(crate) fn binary_base(s: Span) -> IResult<Span, BinaryBase> {
 #[parser]
 pub(crate) 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()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -257,7 +257,7 @@ pub(crate) fn octal_base(s: Span) -> IResult<Span, OctalBase> {
 #[parser]
 pub(crate) 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()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -269,7 +269,7 @@ pub(crate) fn hex_base(s: Span) -> IResult<Span, HexBase> {
 #[parser]
 pub(crate) 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()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -284,7 +284,7 @@ pub(crate) fn x_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
@@ -299,7 +299,7 @@ pub(crate) fn z_number_impl(s: Span) -> IResult<Span, Locate> {
     let (s, a) = fold_many0(alt((tag("_"), is_a("_"))), a, |acc, item| {
         concat(acc, item).unwrap()
     })(s)?;
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
diff --git a/sv-parser-parser/src/expressions/strings.rs b/sv-parser-parser/src/expressions/strings.rs
index 9c3437e..6b2403a 100644
--- a/sv-parser-parser/src/expressions/strings.rs
+++ b/sv-parser-parser/src/expressions/strings.rs
@@ -39,5 +39,5 @@ pub(crate) fn string_literal_impl(s: Span) -> IResult<Span, Locate> {
     let a = concat(a, b).unwrap();
     let a = concat(a, c).unwrap();
 
-    Ok((s, a.into()))
+    Ok((s, into_locate(a)))
 }
diff --git a/sv-parser-parser/src/general/comments.rs b/sv-parser-parser/src/general/comments.rs
index cf93c3b..d30e4ac 100644
--- a/sv-parser-parser/src/general/comments.rs
+++ b/sv-parser-parser/src/general/comments.rs
@@ -12,7 +12,12 @@ pub(crate) 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.into(),) }))
+    Ok((
+        s,
+        Comment {
+            nodes: (into_locate(a),),
+        },
+    ))
 }
 
 #[parser]
@@ -22,5 +27,10 @@ pub(crate) 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.into(),) }))
+    Ok((
+        s,
+        Comment {
+            nodes: (into_locate(a),),
+        },
+    ))
 }
diff --git a/sv-parser-parser/src/general/identifiers.rs b/sv-parser-parser/src/general/identifiers.rs
index 5950224..579d798 100644
--- a/sv-parser-parser/src/general/identifiers.rs
+++ b/sv-parser-parser/src/general/identifiers.rs
@@ -44,7 +44,7 @@ pub(crate) fn c_identifier_impl(s: Span) -> IResult<Span, Locate> {
     if is_keyword(&a) {
         Err(Err::Error(make_error(s, ErrorKind::Fix)))
     } else {
-        Ok((s, a.into()))
+        Ok((s, into_locate(a)))
     }
 }
 
@@ -148,7 +148,7 @@ pub(crate) 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.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[allow(dead_code)]
@@ -637,7 +637,7 @@ pub(crate) fn simple_identifier_impl(s: Span) -> IResult<Span, Locate> {
     if is_keyword(&a) {
         Err(Err::Error(make_error(s, ErrorKind::Fix)))
     } else {
-        Ok((s, a.into()))
+        Ok((s, into_locate(a)))
     }
 }
 
@@ -658,7 +658,7 @@ pub(crate) 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.into()))
+    Ok((s, into_locate(a)))
 }
 
 #[parser]
diff --git a/sv-parser-parser/src/lib.rs b/sv-parser-parser/src/lib.rs
index 852a8a1..8e2e3a2 100644
--- a/sv-parser-parser/src/lib.rs
+++ b/sv-parser-parser/src/lib.rs
@@ -32,12 +32,34 @@ pub(crate) use nom::multi::*;
 pub(crate) use nom::sequence::*;
 pub(crate) use nom::{Err, IResult};
 pub(crate) use nom_packrat::{self, packrat_parser};
-pub(crate) use nom_recursive::{recursive_parser, RecursiveTracer};
+pub(crate) use nom_recursive::{recursive_parser, RecursiveInfo, RecursiveTracer};
 pub(crate) use sv_parser_macros::*;
 pub(crate) use sv_parser_syntaxtree::*;
 
 // -----------------------------------------------------------------------------
 
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+pub struct SpanInfo {
+    #[cfg(feature = "trace")]
+    pub depth: usize,
+    pub recursive_info: RecursiveInfo,
+}
+
+pub type Span<'a> = nom_locate::LocatedSpanEx<&'a str, SpanInfo>;
+
+impl RecursiveTracer for SpanInfo {
+    fn get_info(&self) -> RecursiveInfo {
+        self.recursive_info
+    }
+
+    fn set_info(mut self, info: RecursiveInfo) -> Self {
+        self.recursive_info = info;
+        self
+    }
+}
+
+// -----------------------------------------------------------------------------
+
 nom_packrat::storage!(AnyNode);
 
 pub fn parse_sv(s: &str) -> Result<SourceText, ()> {
diff --git a/sv-parser-parser/src/utils.rs b/sv-parser-parser/src/utils.rs
index 71dc71f..a6a32b1 100644
--- a/sv-parser-parser/src/utils.rs
+++ b/sv-parser-parser/src/utils.rs
@@ -270,8 +270,8 @@ pub(crate) fn symbol<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>, S
     move |s: Span<'a>| {
         #[cfg(feature = "trace")]
         let s = trace(s, &format!("symbol(\"{}\")", t));
-        let (s, x) = map(ws(map(tag(t.clone()), |x: Span| x.into())), |x| Symbol {
-            nodes: x,
+        let (s, x) = map(ws(map(tag(t.clone()), |x: Span| into_locate(x))), |x| {
+            Symbol { nodes: x }
         })(s)?;
         Ok((s, x))
     }
@@ -283,7 +283,7 @@ pub(crate) fn keyword<'a>(t: &'a str) -> impl Fn(Span<'a>) -> IResult<Span<'a>,
         let s = trace(s, &format!("keyword(\"{}\")", t));
         let (s, x) = map(
             ws(terminated(
-                map(tag(t.clone()), |x: Span| x.into()),
+                map(tag(t.clone()), |x: Span| into_locate(x)),
                 peek(none_of(AZ09_)),
             )),
             |x| Keyword { nodes: x },
@@ -427,7 +427,9 @@ where
 #[parser]
 pub(crate) fn white_space(s: Span) -> IResult<Span, WhiteSpace> {
     alt((
-        map(multispace1, |x: Span| WhiteSpace::Space(Box::new(x.into()))),
+        map(multispace1, |x: Span| {
+            WhiteSpace::Space(Box::new(into_locate(x)))
+        }),
         map(comment, |x| WhiteSpace::Comment(Box::new(x))),
     ))(s)
 }
@@ -457,6 +459,14 @@ pub(crate) fn is_keyword(s: &Span) -> bool {
     false
 }
 
+pub(crate) fn into_locate(s: Span) -> Locate {
+    Locate {
+        offset: s.offset,
+        line: s.line,
+        len: s.fragment.len(),
+    }
+}
+
 #[cfg(feature = "trace")]
 pub(crate) fn trace<'a>(mut s: Span<'a>, name: &str) -> Span<'a> {
     println!(
diff --git a/sv-parser-syntaxtree/Cargo.toml b/sv-parser-syntaxtree/Cargo.toml
index 5c4aa05..e92e3b1 100644
--- a/sv-parser-syntaxtree/Cargo.toml
+++ b/sv-parser-syntaxtree/Cargo.toml
@@ -5,14 +5,8 @@ authors = ["dalance <dalance@gmail.com>"]
 edition = "2018"
 build = "build.rs"
 
-[features]
-default = []
-trace = []
-
 [dependencies]
 sv-parser-macros = { path = "../sv-parser-macros" }
-nom_locate       = { path = "../../nom_locate" }
-nom-recursive    = { path = "../../nom-recursive/nom-recursive" }
 
 [build-dependencies]
 walkdir = "2"
diff --git a/sv-parser-syntaxtree/src/lib.rs b/sv-parser-syntaxtree/src/lib.rs
index 7a8b86d..b5deb25 100644
--- a/sv-parser-syntaxtree/src/lib.rs
+++ b/sv-parser-syntaxtree/src/lib.rs
@@ -23,48 +23,15 @@ pub use special_node::*;
 pub use specify_section::*;
 pub use udp_declaration_and_instantiation::*;
 
-pub(crate) use nom_recursive::{RecursiveInfo, RecursiveTracer};
 pub(crate) use sv_parser_macros::*;
 
 // -----------------------------------------------------------------------------
 
-#[derive(Clone, Copy, Debug, Default, PartialEq)]
-pub struct SpanInfo {
-    #[cfg(feature = "trace")]
-    pub depth: usize,
-    pub recursive_info: RecursiveInfo,
-}
-
-pub type Span<'a> = nom_locate::LocatedSpanEx<&'a str, SpanInfo>;
-
-impl RecursiveTracer for SpanInfo {
-    fn get_info(&self) -> RecursiveInfo {
-        self.recursive_info
-    }
-
-    fn set_info(mut self, info: RecursiveInfo) -> Self {
-        self.recursive_info = info;
-        self
-    }
-}
-
-// -----------------------------------------------------------------------------
-
 #[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(),
-        }
-    }
+    pub offset: usize,
+    pub line: u32,
+    pub len: usize,
 }
 
 // -----------------------------------------------------------------------------
diff --git a/sv-parser/Cargo.toml b/sv-parser/Cargo.toml
index 820b73a..5bdf61a 100644
--- a/sv-parser/Cargo.toml
+++ b/sv-parser/Cargo.toml
@@ -15,5 +15,5 @@ default = []
 trace = ["sv-parser-parser/trace"]
 
 [dependencies]
-sv-parser-syntaxtree = { path = "../sv-parser-syntaxtree" }
 sv-parser-parser     = { path = "../sv-parser-parser" }
+sv-parser-syntaxtree = { path = "../sv-parser-syntaxtree" }