Use repeat in initializer lists

corpus/expressions.txt

@@ -332,8 +332,14 @@ Compound literals
 ============================================
 
 int main() {
-  x = (SomeType) { .f1 = 5, .f2 = 6, .f3 = {} };
-  y = (struct SomeStruct) { 7, 8 };
+  x = (SomeType) {
+    .f1.f2[f3] = 5,
+    .f4 = {}
+  };
+  y = (struct SomeStruct) {
+    7,
+    8
+  };
 }
 
 ---
@@ -348,9 +354,14 @@ int main() {
         (compound_literal_expression
           (type_descriptor (type_identifier))
           (initializer_list
-            (designator (field_identifier)) (number_literal)
-            (designator (field_identifier)) (number_literal)
-            (designator (field_identifier)) (initializer_list)))))
+            (initializer_pair
+              (field_designator (field_identifier))
+              (field_designator (field_identifier))
+              (subscript_designator (identifier))
+              (number_literal))
+            (initializer_pair
+              (field_designator (field_identifier))
+              (initializer_list))))))
       (expression_statement (assignment_expression
         (identifier)
         (compound_literal_expression
@@ -364,7 +375,6 @@ Compound literals with trailing commas
 ============================================
 
 int main() {
-  x = (SomeType) { .f1 = 5, .f2 = 6, };
   y = (struct SomeStruct) { 7, 8, };
 }
 
@@ -375,17 +385,10 @@ int main() {
     (primitive_type)
     (function_declarator (identifier) (parameter_list))
     (compound_statement
-      (expression_statement (assignment_expression
-        (identifier)
-        (compound_literal_expression
-          (type_descriptor (type_identifier))
-          (initializer_list
-            (designator (field_identifier)) (number_literal)
-            (designator (field_identifier)) (number_literal)))))
-      (expression_statement (assignment_expression
-        (identifier)
-        (compound_literal_expression
-          (type_descriptor (struct_specifier (type_identifier)))
-          (initializer_list
-            (number_literal)
-            (number_literal))))))))
+    (expression_statement (assignment_expression
+      (identifier)
+      (compound_literal_expression
+        (type_descriptor (struct_specifier (type_identifier)))
+        (initializer_list
+          (number_literal)
+          (number_literal))))))))

grammar.js

@@ -695,30 +695,24 @@ module.exports = grammar({
 
     initializer_list: $ => seq(
       '{',
-      optional(seq(
-        $._initializer_list_contents,
-        optional(',')
+      commaSep(choice(
+        $.initializer_pair,
+        $._expression,
+        $.initializer_list
       )),
+      optional(','),
       '}'
     ),
 
-    _initializer_list_contents: $ => commaSepTrailing(
-      $._initializer_list_contents,
-      seq(
-        optional(seq(repeat1($.designator), '=')),
-        choice($._expression, $.initializer_list)
-      )
+    initializer_pair: $ => seq(
+      repeat1(choice($.subscript_designator, $.field_designator)),
+      '=',
+      choice($._expression, $.initializer_list)
     ),
 
-    designator: $ => choice(
-      seq('[', $._expression, ']'),
-      seq('.', $._field_identifier)
-    ),
+    subscript_designator: $ => seq('[', $._expression, ']'),
 
-    initializer: $ => choice(
-      $._expression,
-      $.initializer_list
-    ),
+    field_designator: $ => seq('.', $._field_identifier),
 
     number_literal: $ => token(seq(
       choice(