[builtins] IndexOf/LastIndexOf implementation for typedarrays

src/js/typedarray.js

 // Copyright 2013 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.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 10 matching lines @@
 var GlobalArrayBufferPrototype = GlobalArrayBuffer.prototype;
 var GlobalDataView = global.DataView;
 var GlobalObject = global.Object;
 var InnerArrayCopyWithin;
 var InnerArrayEvery;
 var InnerArrayFill;
 var InnerArrayFilter;
 var InnerArrayFind;
 var InnerArrayFindIndex;
 var InnerArrayForEach;
-var InnerArrayIndexOf;
 var InnerArrayJoin;
-var InnerArrayLastIndexOf;
 var InnerArrayReduce;
 var InnerArrayReduceRight;
 var InnerArraySome;
 var InnerArraySort;
 var InnerArrayToLocaleString;
 var InternalArray = utils.InternalArray;
 var IsNaN;
 var MaxSimple;
 var MinSimple;
 var PackedArrayReverse;
@@ skipping 28 matching lines @@
   ArrayValues = from.ArrayValues;
   GetIterator = from.GetIterator;
   GetMethod = from.GetMethod;
   InnerArrayCopyWithin = from.InnerArrayCopyWithin;
   InnerArrayEvery = from.InnerArrayEvery;
   InnerArrayFill = from.InnerArrayFill;
   InnerArrayFilter = from.InnerArrayFilter;
   InnerArrayFind = from.InnerArrayFind;
   InnerArrayFindIndex = from.InnerArrayFindIndex;
   InnerArrayForEach = from.InnerArrayForEach;
-  InnerArrayIndexOf = from.InnerArrayIndexOf;
   InnerArrayJoin = from.InnerArrayJoin;
-  InnerArrayLastIndexOf = from.InnerArrayLastIndexOf;
   InnerArrayReduce = from.InnerArrayReduce;
   InnerArrayReduceRight = from.InnerArrayReduceRight;
   InnerArraySome = from.InnerArraySome;
   InnerArraySort = from.InnerArraySort;
   InnerArrayToLocaleString = from.InnerArrayToLocaleString;
   IsNaN = from.IsNaN;
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
   PackedArrayReverse = from.PackedArrayReverse;
   SpeciesConstructor = from.SpeciesConstructor;
@@ skipping 470 matching lines @@
 
   return InnerArraySort(this, length, comparefn);
 }
 
 
 // ES6 section 22.2.3.13
 function TypedArrayIndexOf(element, index) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
-  return InnerArrayIndexOf(this, element, index, length);
+
+  if (length === 0) return -1;
+  var n = TO_INTEGER(index);
+

[Camillo Bruni, 2016/08/12 09:35:17]

If the input is not a number return -1:
if (!IS_NUMBER(element)) return -1;

[mattloring, 2016/08/12 17:52:43]

Done.

+  var k;
+  if (n >= 0) {
+    k = n;
+  } else {
+    k = length + n;
+    if (k < 0) {
+      k = 0;
+    }
+  }
+
+  while (k < length) {
+    var elementK = this[k];
+    if (k in this && element === elementK) {

[Camillo Bruni, 2016/08/12 09:35:17]

This "in" check is not necessary since the typed array is packed and has no
accessors that could modify it's length when reading out an element.

[mattloring, 2016/08/12 17:52:43]

Done.

+      return k;
+    }
+    ++k;
+  }
+  return -1;
 }
 %FunctionSetLength(TypedArrayIndexOf, 1);
 
 
 // ES6 section 22.2.3.16
 function TypedArrayLastIndexOf(element, index) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
 
-  return InnerArrayLastIndexOf(this, element, index, length,
-                               arguments.length);
+  if (length === 0) return -1;
+  var n;
+  if (arguments.length < 2) {
+    n = length - 1;
+  } else {
+    n = TO_INTEGER(index);
+  }

[Camillo Bruni, 2016/08/12 09:35:17]

Add: if (!IS_NUMBER(element)) return -1;

[mattloring, 2016/08/12 17:52:43]

Done.

+
+  var k;
+  if (n >= 0) {
+    if (length <= n) {
+      k = length - 1;
+    } else {
+      k = n;
+    }
+  } else {
+    k = length + n;
+  }
+
+  while (k >= 0) {
+    var elementK = this[k];
+    if (k in this && element === elementK) {

[Camillo Bruni, 2016/08/12 09:35:17]

same here: you can remove the "in" check.

[mattloring, 2016/08/12 17:52:43]

Done.

+      return k;
+    }
+    --k;
+  }
+  return -1;
 }
 %FunctionSetLength(TypedArrayLastIndexOf, 1);
 
 
 // ES6 draft 07-15-13, section 22.2.3.18
 function TypedArrayMap(f, thisArg) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
   var result = TypedArraySpeciesCreate(this, length);
@@ skipping 324 matching lines @@
   "setUint32", DataViewSetUint32JS,
 
   "getFloat32", DataViewGetFloat32JS,
   "setFloat32", DataViewSetFloat32JS,
 
   "getFloat64", DataViewGetFloat64JS,
   "setFloat64", DataViewSetFloat64JS
 ]);
 
 })