Add handling `token` seperator in mbe

7 files changed, 218 insertions, 226 deletions

diff --git a/crates/ra_mbe/Cargo.toml b/crates/ra_mbe/Cargo.toml
index 1d0c2a340..1e5ed6907 100644
--- a/crates/ra_mbe/Cargo.toml
+++ b/crates/ra_mbe/Cargo.toml
@@ -10,3 +10,4 @@ ra_parser = { path = "../ra_parser" }
 tt = { path = "../ra_tt", package = "ra_tt" }
 itertools = "0.8.0"
 rustc-hash = "1.0.0"
+smallvec = "0.6.9"
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index d7b18dd0f..7ebba807c 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -24,6 +24,7 @@ mod subtree_source;
 mod subtree_parser;
 
 use ra_syntax::SmolStr;
+use smallvec::SmallVec;
 
 pub use tt::{Delimiter, Punct};
 
@@ -99,10 +100,17 @@ pub(crate) struct Subtree {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum Separator {
+    Literal(tt::Literal),
+    Ident(tt::Ident),
+    Puncts(SmallVec<[tt::Punct; 3]>),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) struct Repeat {
     pub(crate) subtree: Subtree,
     pub(crate) kind: RepeatKind,
-    pub(crate) separator: Option<char>,
+    pub(crate) separator: Option<Separator>,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -175,8 +183,8 @@ impl_froms!(TokenTree: Leaf, Subtree);
         let expansion = rules.expand(&invocation_tt).unwrap();
         assert_eq!(
         expansion.to_string(),
-        "impl From < Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree :: Leaf (it)}} \
-         impl From < Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree :: Subtree (it)}}"
+        "impl From <Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree ::Leaf (it)}} \
+         impl From <Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree ::Subtree (it)}}"
     )
     }
 
@@ -384,7 +392,7 @@ impl_froms!(TokenTree: Leaf, Subtree);
 "#,
         );
 
-        assert_expansion(&rules, "foo! { foo, bar }", "fn baz {foo () ; bar ()}");
+        assert_expansion(&rules, "foo! { foo, bar }", "fn baz {foo () ;bar ()}");
     }
 
     #[test]
@@ -417,6 +425,18 @@ impl_froms!(TokenTree: Leaf, Subtree);
     }
 
     #[test]
+    fn test_match_group_with_multichar_sep() {
+        let rules = create_rules(
+            r#"
+        macro_rules! foo {            
+            (fn $name:ident {$($i:literal)*} ) => ( fn $name() -> bool { $($i)&&*} );            
+        }"#,
+        );
+
+        assert_expansion(&rules, "foo! (fn baz {true true} )", "fn baz () -> bool {true &&true}");
+    }
+
+    #[test]
     fn test_expand_to_item_list() {
         let rules = create_rules(
             "
@@ -597,7 +617,7 @@ MACRO_ITEMS@[0; 40)
         assert_expansion(
             &rules,
             "foo! { bar::<u8>::baz::<u8> }",
-            "fn foo () {let a = bar :: < u8 > :: baz :: < u8 > ;}",
+            "fn foo () {let a = bar ::< u8 >:: baz ::< u8 > ;}",
         );
     }
 
@@ -891,7 +911,7 @@ MACRO_ITEMS@[0; 40)
         }
 "#,
         );
-        assert_expansion(&rules, r#"foo!{'a}"#, r#"struct Ref < 'a > {s : & 'a str}"#);
+        assert_expansion(&rules, r#"foo!{'a}"#, r#"struct Ref <'a > {s : &'a str}"#);
     }
 
     #[test]
@@ -1063,7 +1083,7 @@ macro_rules! int_base {
         );
 
         assert_expansion(&rules, r#" int_base!{Binary for isize as usize -> Binary}"#, 
-        "# [stable (feature = \"rust1\" , since = \"1.0.0\")] impl fmt :: Binary for isize {fn fmt (& self , f : & mut fmt :: Formatter < \'_ >) -> fmt :: Result {Binary . fmt_int (* self as usize , f)}}"
+        "# [stable (feature = \"rust1\" , since = \"1.0.0\")] impl fmt ::Binary for isize {fn fmt (& self , f : & mut fmt :: Formatter < \'_ >) -> fmt :: Result {Binary . fmt_int (* self as usize , f)}}"
         );
     }
 
@@ -1140,186 +1160,4 @@ impl_fn_for_zst !   {
         assert_expansion(&rules, r#"impl_nonzero_fmt ! { # [ stable ( feature = "nonzero" , since = "1.28.0" ) ] ( Debug , Display , Binary , Octal , LowerHex , UpperHex ) for NonZeroU8 }"#, 
         "fn foo () {}");
     }
-
-    #[test]
-    fn test_tuple_impls() {
-        // from https://github.com/rust-lang/rust/blob/316a391dcb7d66dc25f1f9a4ec9d368ef7615005/src/libcore/num/mod.rs#L12
-        let rules = create_rules(
-            r#"
-    macro_rules! tuple_impls {
-    ($(
-        $Tuple:ident {
-            $(($idx:tt) -> $T:ident)+
-        }
-    )+) => {
-        $(
-            #[stable(feature = "rust1", since = "1.0.0")]
-            impl<$($T:PartialEq),+> PartialEq for ($($T,)+) where last_type!($($T,)+): ?Sized {
-                #[inline]
-                fn eq(&self, other: &($($T,)+)) -> bool {
-                    $(self.$idx == other.$idx)&&+
-                }
-                #[inline]
-                fn ne(&self, other: &($($T,)+)) -> bool {
-                    $(self.$idx != other.$idx)||+
-                }
-            }
-
-            #[stable(feature = "rust1", since = "1.0.0")]
-            impl<$($T:Eq),+> Eq for ($($T,)+) where last_type!($($T,)+): ?Sized {}
-
-            #[stable(feature = "rust1", since = "1.0.0")]
-            impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+)
-                    where last_type!($($T,)+): ?Sized {
-                #[inline]
-                fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
-                    lexical_partial_cmp!($(self.$idx, other.$idx),+)
-                }
-                #[inline]
-                fn lt(&self, other: &($($T,)+)) -> bool {
-                    lexical_ord!(lt, $(self.$idx, other.$idx),+)
-                }
-                #[inline]
-                fn le(&self, other: &($($T,)+)) -> bool {
-                    lexical_ord!(le, $(self.$idx, other.$idx),+)
-                }
-                #[inline]
-                fn ge(&self, other: &($($T,)+)) -> bool {
-                    lexical_ord!(ge, $(self.$idx, other.$idx),+)
-                }
-                #[inline]
-                fn gt(&self, other: &($($T,)+)) -> bool {
-                    lexical_ord!(gt, $(self.$idx, other.$idx),+)
-                }
-            }
-
-            #[stable(feature = "rust1", since = "1.0.0")]
-            impl<$($T:Ord),+> Ord for ($($T,)+) where last_type!($($T,)+): ?Sized {
-                #[inline]
-                fn cmp(&self, other: &($($T,)+)) -> Ordering {
-                    lexical_cmp!($(self.$idx, other.$idx),+)
-                }
-            }
-
-            #[stable(feature = "rust1", since = "1.0.0")]
-            impl<$($T:Default),+> Default for ($($T,)+) {
-                #[inline]
-                fn default() -> ($($T,)+) {
-                    ($({ let x: $T = Default::default(); x},)+)
-                }
-            }
-        )+
-    }
-}"#,
-        );
-
-        assert_expansion(
-            &rules,
-            r#"tuple_impls ! { 
-    Tuple1   { 
-         ( 0 )   ->   A 
-     } 
-     Tuple2   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-     } 
-     Tuple3   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-     } 
-     Tuple4   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-     } 
-     Tuple5   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-     } 
-     Tuple6   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-     } 
-     Tuple7   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-     } 
-     Tuple8   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-         ( 7 )   ->   H 
-     } 
-     Tuple9   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-         ( 7 )   ->   H 
-         ( 8 )   ->   I 
-     } 
-     Tuple10   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-         ( 7 )   ->   H 
-         ( 8 )   ->   I 
-         ( 9 )   ->   J 
-     } 
-     Tuple11   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-         ( 7 )   ->   H 
-         ( 8 )   ->   I 
-         ( 9 )   ->   J 
-         ( 10 )   ->   K 
-     } 
-     Tuple12   { 
-         ( 0 )   ->   A 
-         ( 1 )   ->   B 
-         ( 2 )   ->   C 
-         ( 3 )   ->   D 
-         ( 4 )   ->   E 
-         ( 5 )   ->   F 
-         ( 6 )   ->   G 
-         ( 7 )   ->   H 
-         ( 8 )   ->   I 
-         ( 9 )   ->   J 
-         ( 10 )   ->   K 
-         ( 11 )   ->   L 
-     } 
-}"#,
-            "fn foo () {}",
-        );
-    }
 }
diff --git a/crates/ra_mbe/src/mbe_expander.rs b/crates/ra_mbe/src/mbe_expander.rs
index 91b6db522..7411dd8b1 100644
--- a/crates/ra_mbe/src/mbe_expander.rs
+++ b/crates/ra_mbe/src/mbe_expander.rs
@@ -196,6 +196,7 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
                         "literal" => {
                             let literal =
                                 input.eat_literal().ok_or(ExpandError::UnexpectedToken)?.clone();
+
                             res.inner.insert(
                                 text.clone(),
                                 Binding::Simple(tt::Leaf::from(literal).into()),
@@ -210,7 +211,7 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
                     }
                 }
                 crate::Leaf::Punct(punct) => {
-                    if input.eat_punct() != Some(punct) {
+                    if !input.eat_punct().map(|p| p.char == punct.char).unwrap_or(false) {
                         return Err(ExpandError::UnexpectedToken);
                     }
                 }
@@ -246,8 +247,23 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
                                 }
                             }
 
-                            if let Some(separator) = *separator {
-                                if input.eat_punct().map(|p| p.char) != Some(separator) {
+                            if let Some(separator) = separator {
+                                use crate::Separator::*;
+
+                                if !input
+                                    .eat_seperator()
+                                    .map(|sep| match (sep, separator) {
+                                        (Ident(ref a), Ident(ref b)) => a.text == b.text,
+                                        (Literal(ref a), Literal(ref b)) => a.text == b.text,
+                                        (Puncts(ref a), Puncts(ref b)) if a.len() == b.len() => {
+                                            let a_iter = a.iter().map(|a| a.char);
+                                            let b_iter = b.iter().map(|b| b.char);
+                                            a_iter.eq(b_iter)
+                                        }
+                                        _ => false,
+                                    })
+                                    .unwrap_or(false)
+                                {
                                     input.rollback(memento);
                                     break;
                                 }
@@ -328,7 +344,7 @@ fn expand_tt(
             // Dirty hack to make macro-expansion terminate.
             // This should be replaced by a propper macro-by-example implementation
             let mut limit = 128;
-            let mut has_sep = false;
+            let mut has_seps = 0;
 
             while let Ok(t) = expand_subtree(&repeat.subtree, bindings, nesting) {
                 limit -= 1;
@@ -339,15 +355,28 @@ fn expand_tt(
                 nesting.push(idx + 1);
                 token_trees.push(reduce_single_token(t).into());
 
-                if let Some(sep) = repeat.separator {
-                    let punct =
-                        tt::Leaf::from(tt::Punct { char: sep, spacing: tt::Spacing::Alone });
-                    token_trees.push(punct.into());
-                    has_sep = true;
+                if let Some(ref sep) = repeat.separator {
+                    match sep {
+                        crate::Separator::Ident(ident) => {
+                            has_seps = 1;
+                            token_trees.push(tt::Leaf::from(ident.clone()).into());
+                        }
+                        crate::Separator::Literal(lit) => {
+                            has_seps = 1;
+                            token_trees.push(tt::Leaf::from(lit.clone()).into());
+                        }
+
+                        crate::Separator::Puncts(puncts) => {
+                            has_seps = puncts.len();
+                            for punct in puncts {
+                                token_trees.push(tt::Leaf::from(*punct).into());
+                            }
+                        }
+                    }
                 }
             }
             nesting.pop().unwrap();
-            if has_sep {
+            for _ in 0..has_seps {
                 token_trees.pop();
             }
 
diff --git a/crates/ra_mbe/src/mbe_parser.rs b/crates/ra_mbe/src/mbe_parser.rs
index 0710062d9..c7ab463e2 100644
--- a/crates/ra_mbe/src/mbe_parser.rs
+++ b/crates/ra_mbe/src/mbe_parser.rs
@@ -74,18 +74,11 @@ fn parse_var(p: &mut TtCursor, transcriber: bool) -> Result<crate::Var, ParseErr
     Ok(crate::Var { text, kind })
 }
 
-fn parse_repeat(p: &mut TtCursor, transcriber: bool) -> Result<crate::Repeat, ParseError> {
-    let subtree = p.eat_subtree().unwrap();
-    let mut subtree = parse_subtree(subtree, transcriber)?;
-    subtree.delimiter = crate::Delimiter::None;
-    let sep = p.eat_punct().ok_or(ParseError::Expected(String::from("separator")))?;
-    let (separator, rep) = match sep.char {
-        '*' | '+' | '?' => (None, sep.char),
-        char => {
-            (Some(char), p.eat_punct().ok_or(ParseError::Expected(String::from("separator")))?.char)
-        }
-    };
-
+fn mk_repeat(
+    rep: char,
+    subtree: crate::Subtree,
+    separator: Option<crate::Separator>,
+) -> Result<crate::Repeat, ParseError> {
     let kind = match rep {
         '*' => crate::RepeatKind::ZeroOrMore,
         '+' => crate::RepeatKind::OneOrMore,
@@ -95,6 +88,27 @@ fn parse_repeat(p: &mut TtCursor, transcriber: bool) -> Result<crate::Repeat, Pa
     Ok(crate::Repeat { subtree, kind, separator })
 }
 
+fn parse_repeat(p: &mut TtCursor, transcriber: bool) -> Result<crate::Repeat, ParseError> {
+    let subtree = p.eat_subtree().unwrap();
+    let mut subtree = parse_subtree(subtree, transcriber)?;
+    subtree.delimiter = crate::Delimiter::None;
+
+    if let Some(rep) = p.at_punct() {
+        match rep.char {
+            '*' | '+' | '?' => {
+                p.bump();
+                return mk_repeat(rep.char, subtree, None);
+            }
+            _ => {}
+        }
+    }
+
+    let sep = p.eat_seperator().ok_or(ParseError::Expected(String::from("separator")))?;
+    let rep = p.eat_punct().ok_or(ParseError::Expected(String::from("repeat")))?;
+
+    mk_repeat(rep.char, subtree, Some(sep))
+}
+
 #[cfg(test)]
 mod tests {
     use ra_syntax::{ast, AstNode};
@@ -109,7 +123,7 @@ mod tests {
         is_valid("($i:ident) => ()");
         expect_err("$i:ident => ()", "subtree");
         expect_err("($i:ident) ()", "`=`");
-        expect_err("($($i:ident)_) => ()", "separator");
+        expect_err("($($i:ident)_) => ()", "repeat");
     }
 
     fn expect_err(macro_body: &str, expected: &str) {
diff --git a/crates/ra_mbe/src/subtree_source.rs b/crates/ra_mbe/src/subtree_source.rs
index 3229cfa8f..e979777fe 100644
--- a/crates/ra_mbe/src/subtree_source.rs
+++ b/crates/ra_mbe/src/subtree_source.rs
@@ -342,7 +342,7 @@ impl<'a> TokenSource for SubtreeTokenSource<'a> {
     }
 }
 
-struct TokenPeek<'a, I>
+pub(crate) struct TokenPeek<'a, I>
 where
     I: Iterator<Item = &'a tt::TokenTree>,
 {
@@ -365,7 +365,7 @@ where
         TokenPeek { iter: itertools::multipeek(iter) }
     }
 
-    fn current_punct2(&mut self, p: &tt::Punct) -> Option<((char, char), bool)> {
+    pub fn current_punct2(&mut self, p: &tt::Punct) -> Option<((char, char), bool)> {
         if p.spacing != tt::Spacing::Joint {
             return None;
         }
@@ -375,7 +375,7 @@ where
         Some(((p.char, p1.char), p1.spacing == tt::Spacing::Joint))
     }
 
-    fn current_punct3(&mut self, p: &tt::Punct) -> Option<((char, char, char), bool)> {
+    pub fn current_punct3(&mut self, p: &tt::Punct) -> Option<((char, char, char), bool)> {
         self.current_punct2(p).and_then(|((p0, p1), last_joint)| {
             if !last_joint {
                 None
@@ -437,12 +437,16 @@ fn convert_delim(d: tt::Delimiter, closing: bool) -> TtToken {
 }
 
 fn convert_literal(l: &tt::Literal) -> TtToken {
-    TtToken {
-        kind: classify_literal(&l.text).unwrap().kind,
-        is_joint_to_next: false,
-        text: l.text.clone(),
-        n_tokens: 1,
-    }
+    let kind = classify_literal(&l.text)
+        .map(|tkn| tkn.kind)
+        .or_else(|| match l.text.as_ref() {
+            "true" => Some(SyntaxKind::TRUE_KW),
+            "false" => Some(SyntaxKind::FALSE_KW),
+            _ => None,
+        })
+        .unwrap();
+
+    TtToken { kind, is_joint_to_next: false, text: l.text.clone(), n_tokens: 1 }
 }
 
 fn convert_ident(ident: &tt::Ident) -> TtToken {
diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs
index 38a481029..9cca19dbb 100644
--- a/crates/ra_mbe/src/syntax_bridge.rs
+++ b/crates/ra_mbe/src/syntax_bridge.rs
@@ -133,7 +133,9 @@ fn convert_tt(
     };
 
     let mut token_trees = Vec::new();
-    for child in tt.children_with_tokens().skip(skip_first as usize) {
+    let mut child_iter = tt.children_with_tokens().skip(skip_first as usize).peekable();
+
+    while let Some(child) = child_iter.next() {
         if (skip_first && (child == first_child || child == last_child)) || child.kind().is_trivia()
         {
             continue;
@@ -152,12 +154,25 @@ fn convert_tt(
                         prev = Some(char)
                     }
                     if let Some(char) = prev {
-                        token_trees.push(
-                            tt::Leaf::from(tt::Punct { char, spacing: tt::Spacing::Alone }).into(),
-                        );
+                        let spacing = match child_iter.peek() {
+                            Some(SyntaxElement::Token(token)) => {
+                                if token.kind().is_punct() {
+                                    tt::Spacing::Joint
+                                } else {
+                                    tt::Spacing::Alone
+                                }
+                            }
+                            _ => tt::Spacing::Alone,
+                        };
+
+                        token_trees.push(tt::Leaf::from(tt::Punct { char, spacing }).into());
                     }
                 } else {
-                    let child: tt::TokenTree = if token.kind().is_keyword()
+                    let child: tt::TokenTree = if token.kind() == SyntaxKind::TRUE_KW
+                        || token.kind() == SyntaxKind::FALSE_KW
+                    {
+                        tt::Leaf::from(tt::Literal { text: token.text().clone() }).into()
+                    } else if token.kind().is_keyword()
                         || token.kind() == IDENT
                         || token.kind() == LIFETIME
                     {
diff --git a/crates/ra_mbe/src/tt_cursor.rs b/crates/ra_mbe/src/tt_cursor.rs
index 87bcf8b0d..343416421 100644
--- a/crates/ra_mbe/src/tt_cursor.rs
+++ b/crates/ra_mbe/src/tt_cursor.rs
@@ -1,5 +1,7 @@
 use crate::ParseError;
 use crate::subtree_parser::Parser;
+use crate::subtree_source::TokenPeek;
+use smallvec::{SmallVec, smallvec};
 
 #[derive(Clone)]
 pub(crate) struct TtCursor<'a> {
@@ -162,6 +164,95 @@ impl<'a> TtCursor<'a> {
         }
     }
 
+    fn eat_punct3(&mut self, p: &tt::Punct) -> Option<SmallVec<[tt::Punct; 3]>> {
+        let sec = self.eat_punct()?.clone();
+        let third = self.eat_punct()?.clone();
+        Some(smallvec![p.clone(), sec, third])
+    }
+
+    fn eat_punct2(&mut self, p: &tt::Punct) -> Option<SmallVec<[tt::Punct; 3]>> {
+        let sec = self.eat_punct()?.clone();
+        Some(smallvec![p.clone(), sec])
+    }
+
+    fn eat_multi_char_punct<'b, I>(
+        &mut self,
+        p: &tt::Punct,
+        iter: &mut TokenPeek<'b, I>,
+    ) -> Option<SmallVec<[tt::Punct; 3]>>
+    where
+        I: Iterator<Item = &'b tt::TokenTree>,
+    {
+        if let Some((m, _)) = iter.current_punct3(p) {
+            if let r @ Some(_) = match m {
+                ('<', '<', '=') | ('>', '>', '=') | ('.', '.', '.') | ('.', '.', '=') => {
+                    self.eat_punct3(p)
+                }
+                _ => None,
+            } {
+                return r;
+            }
+        }
+
+        if let Some((m, _)) = iter.current_punct2(p) {
+            if let r @ Some(_) = match m {
+                ('<', '=')
+                | ('>', '=')
+                | ('+', '=')
+                | ('-', '=')
+                | ('|', '=')
+                | ('&', '=')
+                | ('^', '=')
+                | ('/', '=')
+                | ('*', '=')
+                | ('%', '=')
+                | ('&', '&')
+                | ('|', '|')
+                | ('<', '<')
+                | ('>', '>')
+                | ('-', '>')
+                | ('!', '=')
+                | ('=', '>')
+                | ('=', '=')
+                | ('.', '.')
+                | (':', ':') => self.eat_punct2(p),
+
+                _ => None,
+            } {
+                return r;
+            }
+        }
+
+        None
+    }
+
+    pub(crate) fn eat_seperator(&mut self) -> Option<crate::Separator> {
+        match self.eat()? {
+            tt::TokenTree::Leaf(tt::Leaf::Literal(lit)) => {
+                Some(crate::Separator::Literal(lit.clone()))
+            }
+            tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
+                Some(crate::Separator::Ident(ident.clone()))
+            }
+            tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) => {
+                match punct.char {
+                    '*' | '+' | '?' => return None,
+                    _ => {}
+                };
+
+                // FIXME: The parser is only handle some compositeable punct,
+                // But at this phase, some punct still is jointed.
+                // So we by pass that check here.
+                let mut peekable = TokenPeek::new(self.subtree.token_trees[self.pos..].iter());
+                let puncts = self.eat_multi_char_punct(punct, &mut peekable);
+                let puncts = puncts.unwrap_or_else(|| smallvec![punct.clone()]);
+
+                Some(crate::Separator::Puncts(puncts))
+            }
+            _ => None,
+        }
+    }
+
     #[must_use]
     pub(crate) fn save(&self) -> TtCursorMemento {
         TtCursorMemento { pos: self.pos }