ES6: Add support for Array.prototype.fill()

BUG=v8:3273
LOG=Y
R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/240873002

Patch from Adrian Perez <aperez@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21074 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/harmony-array.js

@@ -80,6 +80,49 @@ function ArrayFindIndex(predicate /* thisArg */) {  // length == 1
 }
 
 
+// ES6, draft 04-05-14, section 22.1.3.6
+function ArrayFill(value /* [, start [, end ] ] */) {  // length == 1
+  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.fill");
+
+  var array = ToObject(this);
+  var length = TO_UINT32(array.length);
+
+  var i = 0;
+  var end = length;
+
+  if (%_ArgumentsLength() > 1) {
+    i = %_Arguments(1);
+    i = IS_UNDEFINED(i) ? 0 : TO_INTEGER(i);
+    if (%_ArgumentsLength() > 2) {
+      end = %_Arguments(2);
+      end = IS_UNDEFINED(end) ? length : TO_INTEGER(end);
+    }
+  }
+
+  if (i < 0) {
+    i += length;
+    if (i < 0) i = 0;
+  } else {
+    if (i > length) i = length;
+  }
+
+  if (end < 0) {
+    end += length;
+    if (end < 0) end = 0;
+  } else {
+    if (end > length) end = length;
+  }
+
+  if ((end - i) > 0 && ObjectIsFrozen(array)) {
+    throw MakeTypeError("array_functions_on_frozen",
+                        ["Array.prototype.fill"]);
+  }
+
+  for (; i < end; i++)
+    array[i] = value;
+  return array;
+}
+
 // -------------------------------------------------------------------
 
 function HarmonyArrayExtendArrayPrototype() {
@@ -88,7 +131,8 @@ function HarmonyArrayExtendArrayPrototype() {
   // Set up the non-enumerable functions on the Array prototype object.
   InstallFunctions($Array.prototype, DONT_ENUM, $Array(
     "find", ArrayFind,
-    "findIndex", ArrayFindIndex
+    "findIndex", ArrayFindIndex,
+    "fill", ArrayFill
   ));
 }
 

test/mjsunit/harmony/array-fill.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.
+
+// Flags: --harmony-arrays
+
+assertEquals(1, Array.prototype.find.length);
+
+assertArrayEquals([].fill(8), []);
+assertArrayEquals([0, 0, 0, 0, 0].fill(), [undefined, undefined, undefined, undefined, undefined]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8), [8, 8, 8, 8, 8]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, 1), [0, 8, 8, 8, 8]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, 10), [0, 0, 0, 0, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, -5), [8, 8, 8, 8, 8]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, 1, 4), [0, 8, 8, 8, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, 1, -1), [0, 8, 8, 8, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, 1, 42), [0, 8, 8, 8, 8]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, -3, 42), [0, 0, 8, 8, 8]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, -3, 4), [0, 0, 8, 8, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, -2, -1), [0, 0, 0, 8, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, -1, -3), [0, 0, 0, 0, 0]);
+assertArrayEquals([0, 0, 0, 0, 0].fill(8, undefined, 4), [8, 8, 8, 8, 0]);
+assertArrayEquals([ ,  ,  ,  , 0].fill(8, 1, 3), [, 8, 8, , 0]);
+
+// If the range if empty, the array is not actually modified and
+// should not throw, even when applied to a frozen object.
+assertArrayEquals(Object.freeze([1, 2, 3]).fill(0, 0, 0), [1, 2, 3]);
+
+// Test exceptions
+assertThrows('Object.freeze([0]).fill()', TypeError);
+assertThrows('Array.prototype.fill.call(null)', TypeError);
+assertThrows('Array.prototype.fill.call(undefined)', TypeError);