feat: Use new proc_macro's span apis to get next token with no gap

Fix #86

Author: tao-guo

Cargo.toml

@@ -11,6 +11,7 @@ readme = "README.md"
 version = "1.9.6"
 authors = ["rust-shell-script <[email protected]>"]
 edition = "2018"
+rust-version = "1.88"
 
 [workspace]
 members = ["macros"]

macros/Cargo.toml

@@ -8,14 +8,15 @@ keywords = ["shell", "script", "cli", "process", "pipe"]
 version = "1.9.6"
 authors = ["Tao Guo <[email protected]>"]
 edition = "2018"
+rust-version = "1.88"
 
 [lib]
 proc-macro = true
 
 [dependencies]
 syn = { version = "2", features = ["full"] }
 quote = "1"
-proc-macro2 = "1"
+proc-macro2 = { version = "1.0.86", features = ["span-locations"] }
 proc-macro-error2 = "2"
 
 [dev-dependencies]

macros/src/lexer.rs

@@ -473,12 +473,10 @@ impl<I: Iterator<Item = TokenTree>> TokenStreamPeekable<I> {
         match self.peekable.peek() {
             None => None,
             Some(item) => {
-                let (_, cur_end) = Self::span_location(&self.span);
-                let (new_start, _) = Self::span_location(&item.span());
-                if new_start > cur_end {
-                    None
-                } else {
+                if self.span.end() == item.span().start() {
                     Some(item)
+                } else {
+                    None
                 }
             }
         }
@@ -487,29 +485,4 @@ impl<I: Iterator<Item = TokenTree>> TokenStreamPeekable<I> {
     fn span(&self) -> Span {
         self.span
     }
-
-    // helper function to get (start, end) of Span
-    fn span_location(span: &Span) -> (usize, usize) {
-        let mut start = 0;
-        let mut end = 0;
-        let mut parse_start = true;
-        format!("{:?}", span) // output is like this: #0 bytes(95..97)
-            .chars()
-            .skip_while(|c| *c != '(')
-            .skip(1)
-            .take_while(|c| *c != ')')
-            .for_each(|c| {
-                if c == '.' {
-                    parse_start = false;
-                } else if c.is_ascii_digit() {
-                    let digit = c.to_digit(10).unwrap() as usize;
-                    if parse_start {
-                        start = start * 10 + digit;
-                    } else {
-                        end = end * 10 + digit;
-                    }
-                }
-            });
-        (start, end)
-    }
 }