add support for yield and yield apply

lib/parse.js

@@ -44,7 +44,7 @@
 
 "use strict";
 
-var KEYWORDS = 'break case catch const continue debugger default delete do else finally for function if in instanceof new return switch throw try typeof var void while with';
+var KEYWORDS = 'break case catch const continue debugger default delete do else finally for function if in instanceof new return yield switch throw try typeof var let void while with';
 var KEYWORDS_ATOM = 'false null true';
 var RESERVED_WORDS = 'abstract boolean byte char class double enum export extends final float goto implements import int interface long native package private protected public short static super synchronized this throws transient volatile yield'
     + " " + KEYWORDS_ATOM + " " + KEYWORDS;
@@ -66,6 +66,7 @@ var OPERATORS = makePredicate([
     "instanceof",
     "typeof",
     "new",
+    "yield",
     "void",
     "delete",
     "++",
@@ -577,6 +578,7 @@ var UNARY_PREFIX = makePredicate([
     "typeof",
     "void",
     "delete",
+    "yield",
     "--",
     "++",
     "!",
@@ -1353,6 +1355,10 @@ function parse($TEXT, options) {
         var start = S.token;
         if (is("operator") && UNARY_PREFIX(start.value)) {
             next();
+            if(start.type === "operator" && start.value === "yield" && is("operator", "*")) {
+                start.value = "yield*";
+                next()
+            }
             handle_regexp();
             var ex = make_unary(AST_UnaryPrefix, start.value, maybe_unary(allow_calls));
             ex.start = start;