Merge #1157

1157: Add mbe stmt matcher r=matklad a=edwin0cheng

Add `stmt` matcher in `ra_mbe` , and added corresponding `stmt()` parser in `ra_syntax`. 
This PR also help PR #1148 for `MarcoKind::Items` parsing.

Note: 
* According [the book](https://doc.rust-lang.org/reference/macros-by-example.html), mbe `stmt` matcher will only match statement without the trailing semicolon 
* `item` is a valid statement.





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

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/ra_mbe/src/subtree_parser.rs b/crates/ra_mbe/src/subtree_parser.rs
index 13d5d2169..f075ce245 100644
--- a/crates/ra_mbe/src/subtree_parser.rs
+++ b/crates/ra_mbe/src/subtree_parser.rs
@@ -42,6 +42,10 @@ impl<'a> Parser<'a> {
         self.parse(ra_parser::parse_pat)
     }
 
+    pub fn parse_stmt(self) -> Option<tt::TokenTree> {
+        self.parse(|src, sink| ra_parser::parse_stmt(src, sink, false))
+    }
+
     fn parse<F>(self, f: F) -> Option<tt::TokenTree>
     where
         F: FnOnce(&dyn TokenSource, &mut dyn TreeSink),