Merge #930

930: Add support for parsing multiple if and while-let patterns r=matklad a=vipentti



Co-authored-by: Ville Penttinen <[email protected]>

2 files changed, 24 insertions, 6 deletions

diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index e74305b6a..9f282c74d 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -281,10 +281,16 @@ fn for_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
 
 // test cond
 // fn foo() { if let Some(_) = None {} }
+// fn bar() {
+//     if let Some(_) | Some(_) = None {}
+//     if let | Some(_) = None {}
+//     while let Some(_) | Some(_) = None {}
+//     while let | Some(_) = None {}
+// }
 fn cond(p: &mut Parser) {
     let m = p.start();
     if p.eat(LET_KW) {
-        patterns::pattern(p);
+        patterns::pattern_list(p);
         p.expect(EQ);
     }
     expr_no_struct(p);
@@ -376,11 +382,7 @@ pub(crate) fn match_arm_list(p: &mut Parser) {
 // }
 fn match_arm(p: &mut Parser) -> BlockLike {
     let m = p.start();
-    p.eat(PIPE);
-    patterns::pattern_r(p, TokenSet::empty());
-    while p.eat(PIPE) {
-        patterns::pattern(p);
-    }
+    patterns::pattern_list_r(p, TokenSet::empty());
     if p.at(IF_KW) {
         match_guard(p);
     }
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 9d7da639d..befe6687d 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -8,6 +8,22 @@ pub(super) fn pattern(p: &mut Parser) {
     pattern_r(p, PAT_RECOVERY_SET)
 }
 
+/// Parses a pattern list separated by pipes `|`
+pub(super) fn pattern_list(p: &mut Parser) {
+    pattern_list_r(p, PAT_RECOVERY_SET)
+}
+
+/// Parses a pattern list separated by pipes `|`
+/// using the given `recovery_set`
+pub(super) fn pattern_list_r(p: &mut Parser, recovery_set: TokenSet) {
+    p.eat(PIPE);
+    pattern_r(p, recovery_set);
+
+    while p.eat(PIPE) {
+        pattern_r(p, recovery_set);
+    }
+}
+
 pub(super) fn pattern_r(p: &mut Parser, recovery_set: TokenSet) {
     if let Some(lhs) = atom_pat(p, recovery_set) {
         // test range_pat