From f7890d4ddbde4d7fd3d2e1be0fddaaca727128f7 Mon Sep 17 00:00:00 2001
From: Cyrus Najmabadi <cyrusn@microsoft.com>
Date: Wed, 12 Nov 2014 19:07:35 -0800
Subject: [PATCH] When entering a type context, 'yield' should be allowed (as
 long as you're not in strict mode).

---
 src/services/syntax/parser.ts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/services/syntax/parser.ts b/src/services/syntax/parser.ts
index 8dcb94e32095f..8f8bae4e5495e 100644
--- a/src/services/syntax/parser.ts
+++ b/src/services/syntax/parser.ts
@@ -3778,6 +3778,23 @@ module TypeScript.Parser {
         }
 
         function tryParseType(): ITypeSyntax {
+            // The rules about 'yield' only apply to actual code/expression contexts.  They don't
+            // apply to 'type' contexts.  So we disable these parameters here before moving on.
+            var savedYieldContext = yieldContext;
+            var savedGeneratorParameterContext = generatorParameterContext;
+
+            setYieldContext(false);
+            setGeneratorParameterContext(false);
+
+            var result = tryParseTypeWorker();
+
+            setYieldContext(savedYieldContext);
+            setGeneratorParameterContext(savedGeneratorParameterContext);
+
+            return result;
+        }
+
+        function tryParseTypeWorker(): ITypeSyntax {
             if (isFunctionType()) {
                 return parseFunctionType();
             }