Rewrite token_kind parser without macros

Author: dtolnay

src/fallback.rs

@@ -885,15 +885,17 @@ fn token_tree(input: Cursor) -> PResult<TokenTree> {
     Ok((rest, tt))
 }
 
-named!(token_kind -> TokenTree, alt!(
-    map!(group, |g| TokenTree::Group(crate::Group::_new_stable(g)))
-    |
-    map!(literal, |l| TokenTree::Literal(crate::Literal::_new_stable(l))) // must be before symbol
-    |
-    map!(op, TokenTree::Punct)
-    |
-    symbol
-));
+fn token_kind(input: Cursor) -> PResult<TokenTree> {
+    if let Ok((input, g)) = group(input) {
+        Ok((input, TokenTree::Group(crate::Group::_new_stable(g))))
+    } else if let Ok((input, l)) = literal(input) { // must be before symbol
+        Ok((input, TokenTree::Literal(crate::Literal::_new_stable(l))))
+    } else if let Ok((input, p)) = op(input) {
+        Ok((input, TokenTree::Punct(p)))
+    } else {
+        symbol(input)
+    }
+}
 
 fn group(input: Cursor) -> PResult<Group> {
     let input = skip_whitespace(input);

src/strnom.rs

@@ -162,73 +162,3 @@ pub(crate) fn word_break(input: Cursor) -> PResult<()> {
         Some(_) | None => Ok((input, ())),
     }
 }
-
-macro_rules! named {
-    ($name:ident -> $o:ty, $submac:ident!( $($args:tt)* )) => {
-        fn $name<'a>(i: Cursor<'a>) -> $crate::strnom::PResult<'a, $o> {
-            $submac!(i, $($args)*)
-        }
-    };
-}
-
-macro_rules! alt {
-    ($i:expr, $e:ident | $($rest:tt)*) => {
-        alt!($i, call!($e) | $($rest)*)
-    };
-
-    ($i:expr, $subrule:ident!( $($args:tt)*) | $($rest:tt)*) => {
-        match $subrule!($i, $($args)*) {
-            res @ Ok(_) => res,
-            _ => alt!($i, $($rest)*)
-        }
-    };
-
-    ($i:expr, $subrule:ident!( $($args:tt)* ) => { $gen:expr } | $($rest:tt)+) => {
-        match $subrule!($i, $($args)*) {
-            Ok((i, o)) => Ok((i, $gen(o))),
-            Err(LexError) => alt!($i, $($rest)*)
-        }
-    };
-
-    ($i:expr, $e:ident => { $gen:expr } | $($rest:tt)*) => {
-        alt!($i, call!($e) => { $gen } | $($rest)*)
-    };
-
-    ($i:expr, $e:ident => { $gen:expr }) => {
-        alt!($i, call!($e) => { $gen })
-    };
-
-    ($i:expr, $subrule:ident!( $($args:tt)* ) => { $gen:expr }) => {
-        match $subrule!($i, $($args)*) {
-            Ok((i, o)) => Ok((i, $gen(o))),
-            Err(LexError) => Err(LexError),
-        }
-    };
-
-    ($i:expr, $e:ident) => {
-        alt!($i, call!($e))
-    };
-
-    ($i:expr, $subrule:ident!( $($args:tt)*)) => {
-        $subrule!($i, $($args)*)
-    };
-}
-
-macro_rules! call {
-    ($i:expr, $fun:expr $(, $args:expr)*) => {
-        $fun($i $(, $args)*)
-    };
-}
-
-macro_rules! map {
-    ($i:expr, $submac:ident!( $($args:tt)* ), $g:expr) => {
-        match $submac!($i, $($args)*) {
-            Err(LexError) => Err(LexError),
-            Ok((i, o)) => Ok((i, call!(o, $g)))
-        }
-    };
-
-    ($i:expr, $f:expr, $g:expr) => {
-        map!($i, call!($f), $g)
-    };
-}