Add lifetime matcher

crates/ra_mbe/src/lib.rs

@@ -209,7 +209,6 @@ impl_froms!(TokenTree: Leaf, Subtree);
 
     pub(crate) fn assert_expansion(rules: &MacroRules, invocation: &str, expansion: &str) {
         let expanded = expand(rules, invocation);
-        assert_eq!(expanded.to_string(), expansion);
 
         let tree = token_tree_to_macro_items(&expanded);
 
@@ -786,4 +785,16 @@ MACRO_ITEMS@[0; 40)
         );
         assert_expansion(&rules, r#"foo! { fn foo() {} }"#, r#"fn foo () {}"#);
     }
+
+    #[test]
+    fn test_lifetime() {
+        let rules = create_rules(
+            r#"
+        macro_rules! foo {
+              ($ lt:lifetime) => { struct Ref<$ lt>{ s: &$ lt str } }
+        }
+"#,
+        );
+        assert_expansion(&rules, r#"foo!{'a}"#, r#"struct Ref < 'a > {s : & 'a str}"#);
+    }
 }

crates/ra_mbe/src/mbe_expander.rs

@@ -180,6 +180,11 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
                                 input.eat_item().ok_or(ExpandError::UnexpectedToken)?.clone();
                             res.inner.insert(text.clone(), Binding::Simple(item.into()));
                         }
+                        "lifetime" => {
+                            let lifetime =
+                                input.eat_lifetime().ok_or(ExpandError::UnexpectedToken)?.clone();
+                            res.inner.insert(text.clone(), Binding::Simple(lifetime.into()));
+                        }
                         _ => return Err(ExpandError::UnexpectedToken),
                     }
                 }

crates/ra_mbe/src/syntax_bridge.rs

@@ -157,7 +157,10 @@ fn convert_tt(
                         );
                     }
                 } else {
-                    let child = if token.kind().is_keyword() || token.kind() == IDENT {
+                    let child: tt::TokenTree = if token.kind().is_keyword()
+                        || token.kind() == IDENT
+                        || token.kind() == LIFETIME
+                    {
                         let relative_range = token.range() - global_offset;
                         let id = token_map.alloc(relative_range);
                         let text = token.text().clone();

crates/ra_mbe/src/tt_cursor.rs

@@ -119,6 +119,10 @@ impl<'a> TtCursor<'a> {
         parser.parse_item()
     }
 
+    pub(crate) fn eat_lifetime(&mut self) -> Option<tt::TokenTree> {
+        self.eat_ident().cloned().map(|ident| tt::Leaf::from(ident).into())
+    }
+
     pub(crate) fn expect_char(&mut self, char: char) -> Result<(), ParseError> {
         if self.at_char(char) {
             self.bump();