Implement .indexOf() and .lastIndexOf() on typed arrays

src/harmony-typedarray.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';
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 41 matching lines @@
   var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
   for (var i = 0; i < length; i++) {
     var element = this[i];
     // Prepare break slots for debugger step in.
     if (stepping) %DebugPrepareStepInIfStepping(f);
     var new_receiver = needs_wrapper ? ToObject(receiver) : receiver;
     %_CallFunction(new_receiver, TO_OBJECT_INLINE(element), i, this, f);
   }
 }
 
+// ES6 draft 11-14-14, section 22.2.3.13
+function NAMEIndexOf(element /* fromIndex */) {  // length == 1
+  if (!%IsTypedArray(this)) {
+    throw MakeTypeError('not_typed_array', []);
+  }
+
+  // Typed arrays cannot contain undefined elements.
+  if (IS_UNDEFINED(element)) {
+    return -1;
+  }
+
+  var length = %_TypedArrayGetLength(this);
+  if (length == 0) return -1;
+
+  var n = (%_ArgumentsLength() > 1) ? ToInteger(%_Arguments(1)) : 0;
+  if (n < 0) {
+    n += length;
+    if (n < 0) n = 0;
+  }
+
+  for (; n < length; n++) {
+    if (this[n] === element) return n;
+  }
+  return -1;
+}
+
+// ES6 draft 11-14-14, section 22.2.3.16
+function NAMELastIndexOf(element /* fromIndex */){  // length == 1
+  if (!%IsTypedArray(this)) {
+    throw MakeTypeError('not_typed_array', []);
+  }
+
+  // Typed arrays cannot contain undefined elements.
+  if (IS_UNDEFINED(element)) {
+    return -1;
+  }
+
+  var length = %_TypedArrayGetLength(this);
+  if (length == 0) return -1;
+
+  var n = (%_ArgumentsLength() > 1) ? ToInteger(%_Arguments(1)) : length - 1;
+  if (n < 0) {
+    n += length;
+  } else if (n >= length) {
+    n = length - 1;
+  }
+
+  for (; n >= 0; n--) {
+    if (this[n] === element) return n;
+  }
+  return -1;
+}
+
 // ES6 draft 08-24-14, section 22.2.2.2
 function NAMEOf() {  // length == 0
   var length = %_ArgumentsLength();
   var array = new this(length);
   for (var i = 0; i < length; i++) {
     array[i] = %_Arguments(i);
   }
   return array;
 }
 
 endmacro
 
 TYPED_ARRAYS(TYPED_ARRAY_HARMONY_ADDITIONS)
 
 
 function HarmonyTypedArrayExtendPrototypes() {
 macro EXTEND_TYPED_ARRAY(ARRAY_ID, NAME, ELEMENT_SIZE)
   %CheckIsBootstrapping();
 
   // Set up non-enumerable functions on the object.
   InstallFunctions(global.NAME, DONT_ENUM | DONT_DELETE | READ_ONLY, $Array(
     "of", NAMEOf
   ));
 
   // Set up non-enumerable functions on the prototype object.
-  InstallFunctions(global.NAME.prototype, DONT_ENUM, $Array(
-    "forEach", NAMEForEach
+  InstallFunctions(global.NAME.prototype, DONT_ENUM | DONT_DELETE | READ_ONLY, $Array(
+    "forEach", NAMEForEach,
+    "indexOf", NAMEIndexOf,
+    "lastIndexOf", NAMELastIndexOf
   ));
 endmacro
 
   TYPED_ARRAYS(EXTEND_TYPED_ARRAY)
 }
 
 HarmonyTypedArrayExtendPrototypes();