Optimize complexity

Author: eed3si9n

grammar.js

@@ -607,6 +607,9 @@ module.exports = grammar({
         choice(
           $._annotated_type,
           $.compound_type,
+          // In theory structural_type should just be added to simple_type,
+          // but doing so increases the state of template_body to 4000
+          $._structural_type,
           // This adds _simple_type, but not the above intentionall/y.
           seq($._simple_type, field("arguments", $.arguments)),
           seq($._annotated_type, field("arguments", $.arguments)),
@@ -773,10 +776,16 @@ module.exports = grammar({
         $.match_type,
         $._annotated_type,
         $.literal_type,
+        $._structural_type,
       ),
 
-    // TODO: Make this a visible type, so that _type can be a supertype.
-    _annotated_type: $ => prec.right(seq($._simple_type, repeat($.annotation))),
+    _annotated_type: $ =>
+      prec.right(choice(
+        $.annotated_type,
+        $._simple_type,
+      )),
+
+    annotated_type: $ => prec.right(seq($._simple_type, repeat1($.annotation))),
 
     _simple_type: $ =>
       choice(
@@ -787,7 +796,6 @@ module.exports = grammar({
         $.stable_type_identifier,
         $._type_identifier,
         $.wildcard,
-        $._structural_type,
       ),
 
     compound_type: $ =>