Merge pull request rescript-lang#169 from aspeddro/fix-object-as-aliasing

support as-aliasing-type

Author: nkrkv

grammar.js

@@ -359,7 +359,7 @@ module.exports = grammar({
       optional('|'),
       barSep1($.polyvar_declaration),
       ']',
-      optional(seq('as', $.type_identifier))
+      optional($.as_aliasing_type)
     )),
 
     polyvar_declaration: $ => prec.right(
@@ -393,15 +393,16 @@ module.exports = grammar({
       $.type_annotation,
     ),
 
-    object_type: $ => seq(
+    object_type: $ => prec.left(seq(
       '{',
       choice(
         commaSep1t($._object_type_field),
         seq('.', commaSept($._object_type_field)),
         seq('..', commaSept($._object_type_field)),
       ),
       '}',
-    ),
+      optional($.as_aliasing_type)
+    )),
 
     _object_type_field: $ => alias($.object_type_field, $.field),
 
@@ -732,6 +733,8 @@ module.exports = grammar({
       optional($.type_annotation)
     )),
 
+    as_aliasing_type: $ => seq('as', $.type_identifier),
+
     assert_expression: $ => prec.left(seq('assert', $.expression)),
 
     call_expression: $ => prec('call', seq(

test/corpus/type_declarations.txt

@@ -243,7 +243,7 @@ type foo<'a> = [> #Blue | #DeepBlue | #LightBlue ] as 'a
       (polyvar_declaration (polyvar_identifier))
       (polyvar_declaration (polyvar_identifier))
       (polyvar_declaration (polyvar_identifier))
-      (type_identifier))))
+      (as_aliasing_type (type_identifier)))))
 
 ===========================================
 Function
@@ -299,6 +299,7 @@ type t = {
   "my-field-two": string,
   ...rest
 }
+type t<'a> = {.."name": string} as 'a
 
 ---
 
@@ -318,7 +319,13 @@ type t = {
     (object_type
       (field (property_identifier (string_fragment)) (type_identifier))
       (field (property_identifier (string_fragment)) (type_identifier))
-      (field (type_identifier)))))
+      (field (type_identifier))))
+  (type_declaration
+    (type_identifier)
+    (type_parameters (type_identifier))
+    (object_type
+      (field (property_identifier (string_fragment)) (type_identifier))
+      (as_aliasing_type (type_identifier)))))
 
 ===========================================
 Generic