1 files changed, 43 insertions, 6 deletions

diff --git a/src/parser/grammar/types.rs b/src/parser/grammar/types.rs
index c798edd08..71801d8ef 100644
--- a/src/parser/grammar/types.rs
+++ b/src/parser/grammar/types.rs
@@ -1,14 +1,51 @@
 use super::*;
 
-pub(super) fn type_ref(p: &mut Parser) {
+pub(super) fn ty(p: &mut Parser) {
     match p.current() {
-        IDENT => p.bump(),
-        L_PAREN => {
-            p.bump();
-            p.expect(R_PAREN);
-        }
+        L_PAREN => paren_or_tuple_ty(p),
+        IDENT => path_type(p),
         _ => {
             p.error("expected type");
         }
     }
 }
+
+fn paren_or_tuple_ty(p: &mut Parser) {
+    assert!(p.at(L_PAREN));
+    let m = p.start();
+    p.bump();
+    let mut n_types: u32 = 0;
+    let mut trailing_comma: bool = false;
+    while !p.at(EOF) && !p.at(R_PAREN) {
+        n_types += 1;
+        ty(p);
+        if p.eat(COMMA) {
+            trailing_comma = true;
+        } else {
+            trailing_comma = false;
+            break;
+        }
+    }
+    p.expect(R_PAREN);
+
+    let kind = if n_types == 1 && !trailing_comma {
+        // test paren_type
+        // type T = (i32);
+        PAREN_TYPE
+    } else {
+        // test unit_type
+        // type T = ();
+
+        // test singleton_tuple_type
+        // type T = (i32,);
+        TUPLE_TYPE
+    };
+    m.complete(p, kind);
+}
+
+fn path_type(p: &mut Parser) {
+    assert!(p.at(IDENT));
+    let m = p.start();
+    paths::type_path(p);
+    m.complete(p, PATH_TYPE);
+}