Re-land %TypedArray%.prototype.{map,filter,some}

src/harmony-typedarray.js

Index: src/harmony-typedarray.js
diff --git a/src/harmony-typedarray.js b/src/harmony-typedarray.js
index 2e8499573bc5930cc0e7cb69fdc1c62323c576c4..dd3efe38625f7855631b61f74c07463c21feaed6 100644
--- a/src/harmony-typedarray.js
+++ b/src/harmony-typedarray.js
@@ -30,6 +30,28 @@ DECLARE_GLOBALS(Array)
 
 // -------------------------------------------------------------------
 
+function ConstructTypedArray(constructor, array) {

[adamk, 2015/05/20 18:50:07]

Where is this called?

[arv (Not doing code reviews), 2015/05/20 19:22:31]

Also, this function is defined twice... was there a merge?

[dehrenberg, 2015/05/20 23:39:01]

Yes. OK, I learned my lesson, not to do git conflict resolution late at night.
It was intended to be called in ConstructTypedArrayLike, but apparently I forgot
to call it there (a bug that goes back to the first time I tried to land this
code). Before you ask: it'd be hard to test this code directly until @@species
goes in; I have a test in TypedArray.from, but no test that TypedArray.map
reaches this code.

+  // TODO(littledan): This is an approximation of the spec, which requires
+  // that only real TypedArray classes should be accepted (22.2.2.1.1)
+  if (!IS_SPEC_OBJECT(constructor) || IS_UNDEFINED(constructor.prototype) ||

[adamk, 2015/05/20 18:50:07]

Can you use %IsConstructor here? These checks look quite odd. (if this function
is unused, you can of course ignore this comment)

[dehrenberg, 2015/05/20 23:39:01]

The check is supposed to be an approximation of checking that this is a
TypedArray class. I replaced IS_SPEC_OBJECT with %IsConstructor, but I still
need the next couple checks.

+      !%HasOwnProperty(constructor.prototype, "BYTES_PER_ELEMENT")) {
+    throw MakeTypeError(kNotTypedArray);
+  }
+
+  // TODO(littledan): The spec requires that, rather than directly calling
+  // the constructor, a TypedArray is created with the proper proto and
+  // underlying size and element size, and elements are put in one by one.
+  // By contrast, this would allow subclasses to make a radically different
+  // constructor with different semantics.
+  return new constructor(array);
+}
+
+function ConstructTypedArrayLike(typedArray, arrayContents) {
+  // TODO(littledan): The spec requires that we actuallly use
+  // typedArray.constructor[Symbol.species] (bug v8:4093)
+  return new typedArray.constructor(arrayContents);
+}
+
 function TypedArrayCopyWithin(target, start, end) {
   if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
 
@@ -61,7 +83,7 @@ function TypedArrayForEach(f, receiver) {
 %FunctionSetLength(TypedArrayForEach, 1);
 
 // ES6 draft 04-05-14 section 22.2.3.8
-function TypedArrayFill(value, start , end) {
+function TypedArrayFill(value, start, end) {
   if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
@@ -70,6 +92,16 @@ function TypedArrayFill(value, start , end) {
 }
 %FunctionSetLength(TypedArrayFill, 1);
 
+// ES6 draft 07-15-13, section 22.2.3.9
+function TypedArrayFilter(predicate, thisArg) {
+  if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
+
+  var length = %_TypedArrayGetLength(this);
+  var array = $innerArrayFilter(predicate, thisArg, this, length);
+  return ConstructTypedArrayLike(this, array);
+}
+%FunctionSetLength(TypedArrayFilter, 1);
+
 // ES6 draft 07-15-13, section 22.2.3.10
 function TypedArrayFind(predicate, thisArg) {
   if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
@@ -154,7 +186,30 @@ function TypedArrayLastIndexOf(element, index) {
   return %_CallFunction(this, element, index, length,
                         %_ArgumentsLength(), $innerArrayLastIndexOf);
 }
-%FunctionSetLength(TypedArrayLastIndexOf, 1);
+
+
+// ES6 draft 07-15-13, section 22.2.3.18
+function TypedArrayMap(predicate, thisArg) {
+  if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
+
+  // TODO(littledan): Preallocate rather than making an intermediate
+  // array, for better performance.
+  var length = %_TypedArrayGetLength(this);
+  var array = $innerArrayMap(predicate, thisArg, this, length);
+  return ConstructTypedArrayLike(this, array);
+}
+%FunctionSetLength(TypedArrayMap, 1);
+
+
+// ES6 draft 05-05-15, section 22.2.3.24
+function TypedArraySome(f, receiver) {
+  if (!%IsTypedArray(this)) throw MakeTypeError(kNotTypedArray);
+
+  var length = %_TypedArrayGetLength(this);
+
+  return $innerArraySome(f, receiver, this, length);
+}
+%FunctionSetLength(TypedArraySome, 1);
 
 
 // ES6 draft 08-24-14, section 22.2.2.2
@@ -203,13 +258,17 @@ macro EXTEND_TYPED_ARRAY(NAME)
   $installFunctions(GlobalNAME.prototype, DONT_ENUM, [
     "copyWithin", TypedArrayCopyWithin,
     "every", TypedArrayEvery,
-    "forEach", TypedArrayForEach,
+    "fill", TypedArrayFill,
+    "filter", TypedArrayFilter,
     "find", TypedArrayFind,
     "findIndex", TypedArrayFindIndex,
     "fill", TypedArrayFill,

[adamk, 2015/05/20 18:50:07]

This is a dup of the sorted line above.

[dehrenberg, 2015/05/20 23:39:01]

Done.

     "indexOf", TypedArrayIndexOf,
     "lastIndexOf", TypedArrayLastIndexOf,
+    "forEach", TypedArrayForEach,
+    "map", TypedArrayMap,
     "reverse", TypedArrayReverse,
+    "some", TypedArraySome
     "sort", TypedArraySort
   ]);
 endmacro