Implement %TypedArray%.prototype.{reduce,reduceRight}

This patch implements the last two methods on TypedArrays. These
were previously committed and led to a test failure.

BUG=v8:3578
LOG=Y
R=adamk

Review URL: https://codereview.chromium.org/1154423014

Cr-Commit-Position: refs/heads/master@{#28773}

src/array.js

@@ -1492,21 +1492,14 @@ function ArrayLastIndexOf(element, index) {
 }
 
 
-function ArrayReduce(callback, current) {
-  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduce");
-
-  // Pull out the length so that modifications to the length in the
-  // loop will not affect the looping and side effects are visible.
-  var array = $toObject(this);
-  var length = $toUint32(array.length);
-
+function InnerArrayReduce(callback, current, array, length, argumentsLength) {
   if (!IS_SPEC_FUNCTION(callback)) {
     throw MakeTypeError(kCalledNonCallable, callback);
   }
 
   var is_array = IS_ARRAY(array);
   var i = 0;
-  find_initial: if (%_ArgumentsLength() < 2) {
+  find_initial: if (argumentsLength < 2) {
     for (; i < length; i++) {
       if (HAS_INDEX(array, i, is_array)) {
         current = array[i++];
@@ -1529,21 +1522,27 @@ function ArrayReduce(callback, current) {
 }
 
 
-function ArrayReduceRight(callback, current) {
-  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduceRight");
+function ArrayReduce(callback, current) {
+  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduce");
 
-  // Pull out the length so that side effects are visible before the
-  // callback function is checked.
+  // Pull out the length so that modifications to the length in the
+  // loop will not affect the looping and side effects are visible.
   var array = $toObject(this);
   var length = $toUint32(array.length);
+  return InnerArrayReduce(callback, current, array, length,
+                          %_ArgumentsLength());
+}
+
 
+function InnerArrayReduceRight(callback, current, array, length,
+                               argumentsLength) {
   if (!IS_SPEC_FUNCTION(callback)) {
     throw MakeTypeError(kCalledNonCallable, callback);
   }
 
   var is_array = IS_ARRAY(array);
   var i = length - 1;
-  find_initial: if (%_ArgumentsLength() < 2) {
+  find_initial: if (argumentsLength < 2) {
     for (; i >= 0; i--) {
       if (HAS_INDEX(array, i, is_array)) {
         current = array[i--];
@@ -1565,6 +1564,18 @@ function ArrayReduceRight(callback, current) {
   return current;
 }
 
+
+function ArrayReduceRight(callback, current) {
+  CHECK_OBJECT_COERCIBLE(this, "Array.prototype.reduceRight");
+
+  // Pull out the length so that side effects are visible before the
+  // callback function is checked.
+  var array = $toObject(this);
+  var length = $toUint32(array.length);
+  return InnerArrayReduceRight(callback, current, array, length,
+                               %_ArgumentsLength());
+}
+
 // ES5, 15.4.3.2
 function ArrayIsArray(obj) {
   return IS_ARRAY(obj);
@@ -1673,6 +1684,8 @@ utils.Export(function(to) {
   to.InnerArrayJoin = InnerArrayJoin;
   to.InnerArrayLastIndexOf = InnerArrayLastIndexOf;
   to.InnerArrayMap = InnerArrayMap;
+  to.InnerArrayReduce = InnerArrayReduce;
+  to.InnerArrayReduceRight = InnerArrayReduceRight;
   to.InnerArrayReverse = InnerArrayReverse;
   to.InnerArraySome = InnerArraySome;
   to.InnerArraySort = InnerArraySort;

src/harmony-typedarray.js

@@ -64,6 +64,8 @@ utils.Import(function(from) {
   InnerArrayJoin = from.InnerArrayJoin;
   InnerArrayLastIndexOf = from.InnerArrayLastIndexOf;
   InnerArrayMap = from.InnerArrayMap;
+  InnerArrayReduce = from.InnerArrayReduce;
+  InnerArrayReduceRight = from.InnerArrayReduceRight;
   InnerArrayReverse = from.InnerArrayReverse;
   InnerArraySome = from.InnerArraySome;
   InnerArraySort = from.InnerArraySort;
@@ -265,11 +267,13 @@ function TypedArrayToLocaleString() {
   return InnerArrayToLocaleString(this, length);
 }
 
+
 // ES6 section 22.2.3.28
 function TypedArrayToString() {
   return %_CallFunction(this, ArrayToString);
 }
 
+
 // ES6 section 22.2.3.14
 function TypedArrayJoin(separator) {
   if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
@@ -280,6 +284,28 @@ function TypedArrayJoin(separator) {
 }
 
 
+// ES6 draft 07-15-13, section 22.2.3.19
+function TypedArrayReduce(callback, current) {
+  if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
+
+  var length = %_TypedArrayGetLength(this);
+  return InnerArrayReduce(callback, current, this, length,
+                          %_ArgumentsLength());
+}
+%FunctionSetLength(TypedArrayReduce, 1);
+
+
+// ES6 draft 07-15-13, section 22.2.3.19
+function TypedArrayReduceRight(callback, current) {
+  if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
+
+  var length = %_TypedArrayGetLength(this);
+  return InnerArrayReduceRight(callback, current, this, length,
+                               %_ArgumentsLength());
+}
+%FunctionSetLength(TypedArrayReduceRight, 1);
+
+
 // ES6 draft 08-24-14, section 22.2.2.2
 function TypedArrayOf() {
   var length = %_ArgumentsLength();
@@ -320,6 +346,8 @@ macro EXTEND_TYPED_ARRAY(NAME)
     "lastIndexOf", TypedArrayLastIndexOf,
     "forEach", TypedArrayForEach,
     "map", TypedArrayMap,
+    "reduce", TypedArrayReduce,
+    "reduceRight", TypedArrayReduceRight,
     "reverse", TypedArrayReverse,
     "some", TypedArraySome,
     "sort", TypedArraySort,

src/prologue.js

@@ -164,6 +164,8 @@ function PostNatives(utils) {
     "InnerArrayJoin",
     "InnerArrayLastIndexOf",
     "InnerArrayMap",
+    "InnerArrayReduce",
+    "InnerArrayReduceRight",
     "InnerArrayReverse",
     "InnerArraySome",
     "InnerArraySort",

test/mjsunit/harmony/typedarray-reduce.js

+// Copyright 2015 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
+
+var typedArrayConstructors = [
+  Uint8Array,
+  Int8Array,
+  Uint16Array,
+  Int16Array,
+  Uint32Array,
+  Int32Array,
+  Uint8ClampedArray,
+  Float32Array,
+  Float64Array
+];
+
+function clone(v) {
+  // Shallow-copies arrays, returns everything else verbatim.
+  if (v instanceof Array) {
+    // Shallow-copy an array.
+    var newArray = new Array(v.length);
+    for (var i in v) {
+      newArray[i] = v[i];
+    }
+    return newArray;
+  }
+  return v;
+}
+
+
+// Creates a callback function for reduce/reduceRight that tests the number
+// of arguments and otherwise behaves as "func", but which also
+// records all calls in an array on the function (as arrays of arguments
+// followed by result).
+function makeRecorder(func, testName) {
+  var record = [];
+  var f = function recorder(a, b, i, s) {
+    assertEquals(4, arguments.length,
+                 testName + "(number of arguments: " + arguments.length + ")");
+    assertEquals("number", typeof(i), testName + "(index must be number)");
+    assertEquals(s[i], b, testName + "(current argument is at index)");
+    if (record.length > 0) {
+      var prevRecord = record[record.length - 1];
+      var prevResult = prevRecord[prevRecord.length - 1];
+      assertEquals(prevResult, a,
+                   testName + "(prev result -> current input)");
+    }
+    var args = [clone(a), clone(b), i, clone(s)];
+    var result = func.apply(this, arguments);
+    args.push(clone(result));
+    record.push(args);
+    return result;
+  };
+  f.record = record;
+  return f;
+}
+
+
+function testReduce(type,
+                    testName,
+                    expectedResult,
+                    expectedCalls,
+                    array,
+                    combine,
+                    init) {
+  var rec = makeRecorder(combine);
+  var result;
+  var performsCall;
+  if (arguments.length > 6) {
+    result = array[type](rec, init);
+  } else {
+    result = array[type](rec);
+  }
+  var calls = rec.record;
+  assertEquals(expectedCalls.length, calls.length,
+               testName + " (number of calls)");
+  for (var i = 0; i < expectedCalls.length; i++) {
+    assertEquals(expectedCalls[i], calls[i],
+                 testName + " (call " + (i + 1) + ")");
+  }
+  assertEquals(expectedResult, result, testName + " (result)");
+}
+
+
+function sum(a, b) { return a + b; }
+function prod(a, b) { return a * b; }
+function dec(a, b, i, arr) { return a + b * Math.pow(10, arr.length - i - 1); }
+function accumulate(acc, elem, i) { acc[i] = elem; return acc; }
+
+for (var constructor of typedArrayConstructors) {
+  // ---- Test Reduce[Left]
+
+  var simpleArray = new constructor([2,4,6])
+
+  testReduce("reduce", "SimpleReduceSum", 12,
+             [[0, 2, 0, simpleArray, 2],
+              [2, 4, 1, simpleArray, 6],
+              [6, 6, 2, simpleArray, 12]],
+             simpleArray, sum, 0);
+
+  testReduce("reduce", "SimpleReduceProd", 48,
+             [[1, 2, 0, simpleArray, 2],
+              [2, 4, 1, simpleArray, 8],
+              [8, 6, 2, simpleArray, 48]],
+             simpleArray, prod, 1);
+
+  testReduce("reduce", "SimpleReduceDec", 246,
+             [[0, 2, 0, simpleArray, 200],
+              [200, 4, 1, simpleArray, 240],
+              [240, 6, 2, simpleArray, 246]],
+             simpleArray, dec, 0);
+
+  testReduce("reduce", "SimpleReduceAccumulate", [2, 4, 6],
+             [[[], 2, 0, simpleArray, [2]],
+              [[2], 4, 1, simpleArray, [2, 4]],
+              [[2,4], 6, 2, simpleArray, [2, 4, 6]]],
+             simpleArray, accumulate, []);
+
+
+  testReduce("reduce", "EmptyReduceSum", 0, [], [], sum, 0);
+  testReduce("reduce", "EmptyReduceProd", 1, [], [], prod, 1);
+  testReduce("reduce", "EmptyReduceDec", 0, [], [], dec, 0);
+  testReduce("reduce", "EmptyReduceAccumulate", [], [], [], accumulate, []);
+
+  testReduce("reduce", "EmptyReduceSumNoInit", 0, [], [0], sum);
+  testReduce("reduce", "EmptyReduceProdNoInit", 1, [], [1], prod);
+  testReduce("reduce", "EmptyReduceDecNoInit", 0, [], [0], dec);
+  testReduce("reduce", "EmptyReduceAccumulateNoInit", [], [], [[]], accumulate);
+
+  // ---- Test ReduceRight
+
+  testReduce("reduceRight", "SimpleReduceRightSum", 12,
+             [[0, 6, 2, simpleArray, 6],
+              [6, 4, 1, simpleArray, 10],
+              [10, 2, 0, simpleArray, 12]],
+             simpleArray, sum, 0);
+
+  testReduce("reduceRight", "SimpleReduceRightProd", 48,
+             [[1, 6, 2, simpleArray, 6],
+              [6, 4, 1, simpleArray, 24],
+              [24, 2, 0, simpleArray, 48]],
+             simpleArray, prod, 1);
+
+  testReduce("reduceRight", "SimpleReduceRightDec", 246,
+             [[0, 6, 2, simpleArray, 6],
+              [6, 4, 1, simpleArray, 46],
+              [46, 2, 0, simpleArray, 246]],
+             simpleArray, dec, 0);
+
+
+  testReduce("reduceRight", "EmptyReduceRightSum", 0, [], [], sum, 0);
+  testReduce("reduceRight", "EmptyReduceRightProd", 1, [], [], prod, 1);
+  testReduce("reduceRight", "EmptyReduceRightDec", 0, [], [], dec, 0);
+  testReduce("reduceRight", "EmptyReduceRightAccumulate", [],
+             [], [], accumulate, []);
+
+  testReduce("reduceRight", "EmptyReduceRightSumNoInit", 0, [], [0], sum);
+  testReduce("reduceRight", "EmptyReduceRightProdNoInit", 1, [], [1], prod);
+  testReduce("reduceRight", "EmptyReduceRightDecNoInit", 0, [], [0], dec);
+  testReduce("reduceRight", "EmptyReduceRightAccumulateNoInit",
+             [], [], [[]], accumulate);
+
+  // Ignore non-array properties:
+
+  var arrayPlus = [1,2,3];
+  arrayPlus[-1] = NaN;
+  arrayPlus[Math.pow(2,32)] = NaN;
+  arrayPlus[NaN] = NaN;
+  arrayPlus["00"] = NaN;
+  arrayPlus["02"] = NaN;
+  arrayPlus["-0"] = NaN;
+
+  testReduce("reduce", "ArrayWithNonElementPropertiesReduce", 6,
+             [[0, 1, 0, arrayPlus, 1],
+              [1, 2, 1, arrayPlus, 3],
+              [3, 3, 2, arrayPlus, 6],
+             ], arrayPlus, sum, 0);
+
+  testReduce("reduceRight", "ArrayWithNonElementPropertiesReduceRight", 6,
+             [[0, 3, 2, arrayPlus, 3],
+              [3, 2, 1, arrayPlus, 5],
+              [5, 1, 0, arrayPlus, 6],
+             ], arrayPlus, sum, 0);
+
+
+  // Test error conditions:
+
+  var exception = false;
+  try {
+    new constructor([1]).reduce("not a function");
+  } catch (e) {
+    exception = true;
+    assertTrue(e instanceof TypeError,
+               "reduce callback not a function not throwing TypeError");
+    assertTrue(e.message.indexOf(" is not a function") >= 0,
+               "reduce non function TypeError type");
+  }
+  assertTrue(exception);
+
+  exception = false;
+  try {
+    new constructor([1]).reduceRight("not a function");
+  } catch (e) {
+    exception = true;
+    assertTrue(e instanceof TypeError,
+               "reduceRight callback not a function not throwing TypeError");
+    assertTrue(e.message.indexOf(" is not a function") >= 0,
+               "reduceRight non function TypeError type");
+  }
+  assertTrue(exception);
+
+  exception = false;
+  try {
+    new constructor([]).reduce(sum);
+  } catch (e) {
+    exception = true;
+    assertTrue(e instanceof TypeError,
+               "reduce no initial value not throwing TypeError");
+    assertEquals("Reduce of empty array with no initial value", e.message,
+                 "reduce no initial TypeError type");
+  }
+  assertTrue(exception);
+
+  exception = false;
+  try {
+    new constructor([]).reduceRight(sum);
+  } catch (e) {
+    exception = true;
+    assertTrue(e instanceof TypeError,
+               "reduceRight no initial value not throwing TypeError");
+    assertEquals("Reduce of empty array with no initial value", e.message,
+                 "reduceRight no initial TypeError type");
+  }
+  assertTrue(exception);
+
+  // Reduce fails when called on non-TypedArrays
+  assertThrows(function() {
+    constructor.prototype.reduce.call([], function() {}, null);
+  }, TypeError);
+  assertThrows(function() {
+    constructor.prototype.reduceRight.call([], function() {}, null);
+  }, TypeError);
+
+  // Shadowing length doesn't affect every, unlike Array.prototype.every
+  var a = new constructor([1, 2]);
+  Object.defineProperty(a, 'length', {value: 1});
+  assertEquals(a.reduce(sum, 0), 3);
+  assertEquals(Array.prototype.reduce.call(a, sum, 0), 1);
+  assertEquals(a.reduceRight(sum, 0), 3);
+  assertEquals(Array.prototype.reduceRight.call(a, sum, 0), 1);
+
+  assertEquals(1, constructor.prototype.reduce.length);
+  assertEquals(1, constructor.prototype.reduceRight.length);
+}