Implement ES6 String.raw behind --harmony-templates

src/harmony-templates.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 function GetTemplateCallSite(siteObj, rawStrings) {
   // TODO(caitp): ensure same template callsite is used for subsequent tag calls
 
   %AddNamedProperty(siteObj, "raw", %ObjectFreeze(rawStrings),
       READ_ONLY | DONT_ENUM | DONT_DELETE);
 
   return %ObjectFreeze(siteObj);
 }
+
+
+// ES6 Draft 10-14-2014, section 21.1.2.4
+function StringRaw(callSite) {
+  // TODO(*): Use rest parameters when implemented

[arv (Not doing code reviews), 2014/11/18 19:05:27]

We always use a name here. The name should be of the person to ask questions to,
not necessarily the person that needs to fix the issue.

[caitp (gmail), 2014/11/18 19:11:54]

Done.

+  var numberOfSubstitutions = %_ArgumentsLength();
+  var cooked = ToObject(callSite);
+  var raw = ToObject(cooked.raw);
+  var literalSegments = ToLength(raw.length);
+  if (literalSegments <= 0) return "";
+
+  var result = ToString(raw[0]);
+
+  for (var i = 1; i < literalSegments; ++i) {
+    if (i < numberOfSubstitutions) {
+      result += ToString(%_Arguments(i));
+    }
+    result += ToString(raw[i]);
+  }
+
+  return result;
+}
+
+
+// -------------------------------------------------------------------

[arv (Not doing code reviews), 2014/11/18 19:05:27]

skip this line

[caitp (gmail), 2014/11/18 19:11:54]

Done.

+
+function ExtendStringForTemplates() {
+  %CheckIsBootstrapping();
+
+  // Set up the non-enumerable functions on the String object.
+  InstallFunctions($String, DONT_ENUM, $Array(
+    "raw", StringRaw
+  ));
+}
+
+ExtendStringForTemplates();