Merge #1209

1209: Bugs fixes And Improvements of MBE r=matklad a=edwin0cheng

This PR fixed / improve followings things:

* Add `token` `$repeat` separator support: Previously $repeat only support single punct separator. 
* Fixed a bug which expand infinite pattern, see `test_match_group_in_group` 
* Correctly handle +,*,? case of $repeat patterns
* Increase the limit of $repeat patterns (128 => 65536), personally i think we could remove this limit as we seem to fix all major loop bugs
* **Re-enable tt matcher**
* Better meta item parsing.
* Add related tests and add some real world test cases.
* Add more debug information.


Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 16 insertions, 1 deletions

diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index 67eae749d..a538ec081 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -119,7 +119,22 @@ pub(crate) fn meta_item(p: &mut Parser) {
             items::token_tree(p);
             break;
         } else {
-            p.bump();
+            // https://doc.rust-lang.org/reference/attributes.html
+            // https://doc.rust-lang.org/reference/paths.html#simple-paths
+            // The start of an meta must be a simple path
+            match p.current() {
+                IDENT | COLONCOLON | SUPER_KW | SELF_KW | CRATE_KW => p.bump(),
+                EQ => {
+                    p.bump();
+                    match p.current() {
+                        c if c.is_literal() => p.bump(),
+                        TRUE_KW | FALSE_KW => p.bump(),
+                        _ => {}
+                    }
+                    break;
+                }
+                _ => break,
+            }
         }
     }