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// Copyright 2019 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.
namespace typed_array_filter {
const kBuiltinName: constexpr string = '%TypedArray%.prototype.filter';
extern runtime TypedArrayCopyElements(Context, JSTypedArray, Object, Number):
void;
// https://tc39.github.io/ecma262/#sec-%typedarray%.prototype.filter
transitioning javascript builtin TypedArrayPrototypeFilter(
js-implicit context: Context, receiver: JSAny)(...arguments): JSAny {
// arguments[0] = callback
// arguments[1] = thisArg
try {
// 1. Let O be the this value.
// 2. Perform ? ValidateTypedArray(O).
const array: JSTypedArray = Cast<JSTypedArray>(receiver)
otherwise ThrowTypeError(kNotTypedArray, kBuiltinName);
const src = typed_array::EnsureAttached(array) otherwise IsDetached;
// 3. Let len be O.[[ArrayLength]].
// TODO(v8:4153): Support huge TypedArrays here.
const len = Cast<Smi>(Convert<Number>(src.length)) otherwise unreachable;
// 4. If IsCallable(callbackfn) is false, throw a TypeError exception.
const callbackfn = Cast<Callable>(arguments[0])
otherwise ThrowTypeError(kCalledNonCallable, arguments[0]);
// 5. If thisArg is present, let T be thisArg; else let T be undefined.
const thisArg: JSAny = arguments[1];
// 6. Let kept be a new empty List.
let kept = growable_fixed_array::NewGrowableFixedArray();
let witness = typed_array::NewAttachedJSTypedArrayWitness(src);
// 7. Let k be 0.
// 8. Let captured be 0.
// 9. Repeat, while k < len
for (let k: Smi = 0; k < len; k++) {
witness.Recheck() otherwise IsDetached;
// a. Let Pk be ! ToString(k).
// b. Let kValue be ? Get(O, Pk).
const value: JSAny = witness.Load(k);
// c. Let selected be ToBoolean(? Call(callbackfn, T, « kValue, k, O
// »)).
const selected: JSAny =
Call(context, callbackfn, thisArg, value, k, witness.GetStable());
// d. If selected is true, then
// i. Append kValue to the end of kept.
// ii. Increase captured by 1.
if (ToBoolean(selected)) kept.Push(value);
// e.Increase k by 1.
}
// 10. Let A be ? TypedArraySpeciesCreate(O, captured).
const lengthSmi = Convert<PositiveSmi>(kept.length);
const typedArray: JSTypedArray =
typed_array_createtypedarray::TypedArraySpeciesCreateByLength(
kBuiltinName, array, lengthSmi);
// 11. Let n be 0.
// 12. For each element e of kept, do
// a. Perform ! Set(A, ! ToString(n), e, true).
// b. Increment n by 1.
TypedArrayCopyElements(context, typedArray, kept.ToJSArray(), lengthSmi);
// 13. Return A.
return typedArray;
}
label IsDetached deferred {
ThrowTypeError(kDetachedOperation, kBuiltinName);
}
}
}
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