Unified: Add tuple_pattern

Author: asgerf

unified/extractor/ast_types.yml

@@ -22,6 +22,7 @@ supertypes:
   pattern:
     - var_pattern
     - apply_pattern
+    - tuple_pattern
     - ignore_pattern
     - unsupported_node
 named:
@@ -109,6 +110,10 @@ named:
     constructor: expr
     argument*: pattern
 
+  # A tuple pattern such as `(a, b)` in `let (a, b) = pair`.
+  tuple_pattern:
+    element*: pattern
+
   # An simple unqualified identifier token
   identifier:
 

unified/extractor/src/languages/swift/swift.rs

@@ -244,14 +244,11 @@ fn translation_rules() -> Vec<yeast::Rule> {
         ),
         // Tuple destructuring pattern, e.g. `let (a, b) = pair`. The parser
         // emits a `pattern` node whose unnamed children are themselves
-        // `pattern` nodes. We synthesize a `tuple` constructor since the
-        // syntax has no name.
+        // `pattern` nodes.
         rule!(
             (pattern (pattern)+ @parts)
             =>
-            (apply_pattern
-                constructor: (name_expr identifier: (identifier "tuple"))
-                argument: {..parts})
+            (tuple_pattern element: {..parts})
         ),
         // ---- Variable declarations ----
         // Handles single (`let x = e`), multiple (`let x = 1, y = 2`),

unified/extractor/tests/corpus/swift/variables.txt

@@ -151,15 +151,12 @@ top_level
             name_expr
               identifier: identifier "pair"
           pattern:
-            apply_pattern
-              argument:
+            tuple_pattern
+              element:
                 var_pattern
                   identifier: identifier "a"
                 var_pattern
                   identifier: identifier "b"
-              constructor:
-                name_expr
-                  identifier: identifier "tuple"
 
 ===
 Multiple bindings on one line