[es6] Re-implement rest parameters via desugaring.

test/mjsunit/harmony/arrow-rest-params-lazy-parsing.js

-// Copyright 2014 the V8 project authors. All rights reserved.
+// Copyright 2015 the V8 project authors. All rights reserved.

[wingo, 2015/08/31 13:07:31]

IIRC we don't update these lines; Adam?

[caitp (gmail), 2015/08/31 13:23:40]

This isn't really an update, it's a new file

 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --harmony-rest-parameters --harmony-arrow-functions
+// Flags: --min-preparse-length=0
 
 (function testRestIndex() {
   assertEquals(5, ((...args) => args.length)(1,2,3,4,5));
   assertEquals(4, ((a, ...args) => args.length)(1,2,3,4,5));
   assertEquals(3, ((a, b, ...args) => args.length)(1,2,3,4,5));
   assertEquals(2, ((a, b, c, ...args) => args.length)(1,2,3,4,5));
   assertEquals(1, ((a, b, c, d, ...args) => args.length)(1,2,3,4,5));
   assertEquals(0, ((a, b, c, d, e, ...args) => args.length)(1,2,3,4,5));
 })();
 
 // strictTest and sloppyTest should be called with descending natural
 // numbers, as in:
 //
 //   strictTest(6,5,4,3,2,1)
 //
-var strictTest = (() => {
+var strictTest = (function() {

[wingo, 2015/08/31 13:07:31]

Why this change?

[caitp (gmail), 2015/08/31 13:23:40]

It's not legal to have a language mode directive in a function with a rest
parameter

   "use strict";
   return (a, b, ...c) => {
     assertEquals(Array, c.constructor);
     assertTrue(Array.isArray(c));
 
     var expectedLength = (a === undefined) ? 0 : a - 2;
     assertEquals(expectedLength, c.length);
 
     for (var i = 2; i < a; ++i) {
       assertEquals(c[i - 2], a - i);
     }
   };
 })();
 
 var sloppyTest = (a, b, ...c) => {
   assertEquals(Array, c.constructor);
   assertTrue(Array.isArray(c));
 
   var expectedLength = (a === undefined) ? 0 : a - 2;
   assertEquals(expectedLength, c.length);
 
   for (var i = 2; i < a; ++i) {
     assertEquals(c[i - 2], a - i);
   }
-}
+};
 
 
 var O = {
   strict: strictTest,
   sloppy: sloppyTest
 };
 
 (function testStrictRestParamArity() {
   assertEquals(2, strictTest.length);
   assertEquals(2, O.strict.length);
@@ skipping 35 matching lines @@
   O.strict.call(O, 3, 2, 1);
 })();
 
 
 (function testsloppyRestParamArity() {
   assertEquals(2, sloppyTest.length);
   assertEquals(2, O.sloppy.length);
 })();
 
 
-(function testRestParamssloppyMode() {
+(function testRestParamsSloppyMode() {
   sloppyTest();
   sloppyTest(2, 1);
   sloppyTest(6, 5, 4, 3, 2, 1);
   sloppyTest(3, 2, 1);
   O.sloppy();
   O.sloppy(2, 1);
   O.sloppy(6, 5, 4, 3, 2, 1);
   O.sloppy(3, 2, 1);
 })();
 
@@ skipping 22 matching lines @@
 })();
 
 
 (function testUnmappedArguments() {
   // Normal functions make their arguments object unmapped, but arrow
   // functions don't have an arguments object anyway.  Check that the
   // right thing happens for arguments in arrow functions with rest
   // parameters.
   assertSame(arguments, ((...rest) => arguments)());
 })();