Implement TypedArray.slice().

src/typedarray.js

Index: src/typedarray.js
diff --git a/src/typedarray.js b/src/typedarray.js
index 4e3b9385863a20c94234d3dc63bafb31191e31f1..2d89b0c2cbcaa7825f2a218cee7abb0c99d9157f 100644
--- a/src/typedarray.js
+++ b/src/typedarray.js
@@ -147,6 +147,40 @@ function NAME_GetLength() {
 
 var $NAME = global.NAME;
 
+function NAMESlice(begin, end) {
+  if (!(%_ClassOf(this) === 'NAME')) {

[arv (Not doing code reviews), 2015/05/01 14:09:31]

This is not quite right. We need to use ValidateTypeArray here.

https://people.mozilla.org/~jorendorff/es6-draft.html#sec-validatetypedarray

+    throw MakeTypeError(kIncompatibleMethodReceiver, "NAME.slice", this);
+  }
+  var beginInt = TO_INTEGER(begin);
+  if (!IS_UNDEFINED(end)) {
+    end = TO_INTEGER(end);
+  }
+
+  var srcLength = %_TypedArrayGetLength(this);
+  if (beginInt < 0) {
+    beginInt = $max(0, srcLength + beginInt);
+  } else {
+    beginInt = $min(srcLength, beginInt);
+  }
+
+  var endInt = IS_UNDEFINED(end) ? srcLength : end;
+  if (endInt < 0) {
+    endInt = $max(0, srcLength + endInt);
+  } else {
+    endInt = $min(endInt, srcLength);
+  }
+  if (endInt < beginInt) {
+    endInt = beginInt;
+  }
+  var newLength = endInt - beginInt;
+  var beginByteOffset =
+      %_ArrayBufferViewGetByteOffset(this) + beginInt * ELEMENT_SIZE;
+  var arrayBuffer = %TypedArrayGetBuffer(this);
+  var arrayBufferSlice = new GlobalArrayBuffer(newLength * ELEMENT_SIZE);
+  %ArrayBufferSliceImpl(arrayBuffer, arrayBufferSlice, beginByteOffset);
+  return new $NAME(arrayBufferSlice, 0, newLength);
+}
+
 function NAMESubArray(begin, end) {
   if (!(%_ClassOf(this) === 'NAME')) {
     throw MakeTypeError(kIncompatibleMethodReceiver, "NAME.subarray", this);
@@ -317,6 +351,7 @@ macro SETUP_TYPED_ARRAY(ARRAY_ID, NAME, ELEMENT_SIZE)
   InstallGetter(global.NAME.prototype, symbolToStringTag,
                 TypedArrayGetToStringTag);
   InstallFunctions(global.NAME.prototype, DONT_ENUM, [
+    "slice", NAMESlice,
     "subarray", NAMESubArray,
     "set", TypedArraySet
   ]);