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LibJS: Implement proposed TypedArray.prototype.findLast{,Index}

Proposal: https://tc39.es/proposal-array-find-from-last/
This commit is contained in:
davidot 2021-08-06 15:39:25 +02:00 committed by Linus Groh
parent b6523906b3
commit 871a29884d
4 changed files with 302 additions and 0 deletions

View file

@ -34,6 +34,8 @@ void TypedArrayPrototype::initialize(GlobalObject& object)
define_native_function(vm.names.fill, fill, 1, attr); define_native_function(vm.names.fill, fill, 1, attr);
define_native_function(vm.names.find, find, 1, attr); define_native_function(vm.names.find, find, 1, attr);
define_native_function(vm.names.findIndex, find_index, 1, attr); define_native_function(vm.names.findIndex, find_index, 1, attr);
define_native_function(vm.names.findLast, find_last, 1, attr);
define_native_function(vm.names.findLastIndex, find_last_index, 1, attr);
define_native_function(vm.names.forEach, for_each, 1, attr); define_native_function(vm.names.forEach, for_each, 1, attr);
define_native_function(vm.names.includes, includes, 1, attr); define_native_function(vm.names.includes, includes, 1, attr);
define_native_function(vm.names.indexOf, index_of, 1, attr); define_native_function(vm.names.indexOf, index_of, 1, attr);
@ -129,6 +131,34 @@ static void for_each_item(VM& vm, GlobalObject& global_object, const String& nam
} }
} }
static void for_each_item_from_last(VM& vm, GlobalObject& global_object, const String& name, Function<IterationDecision(size_t index, Value value, Value callback_result)> callback)
{
auto* typed_array = validate_typed_array_from_this(global_object);
if (!typed_array)
return;
auto initial_length = typed_array->array_length();
auto* callback_function = callback_from_args(global_object, name);
if (!callback_function)
return;
auto this_value = vm.argument(1);
for (ssize_t i = (ssize_t)initial_length - 1; i >= 0; --i) {
auto value = typed_array->get(i);
if (vm.exception())
return;
auto callback_result = vm.call(*callback_function, this_value, value, Value((i32)i), typed_array);
if (vm.exception())
return;
if (callback(i, value, callback_result) == IterationDecision::Break)
break;
}
}
// 23.2.4.1 TypedArraySpeciesCreate ( exemplar, argumentList ), https://tc39.es/ecma262/#typedarray-species-create // 23.2.4.1 TypedArraySpeciesCreate ( exemplar, argumentList ), https://tc39.es/ecma262/#typedarray-species-create
static TypedArrayBase* typed_array_species_create(GlobalObject& global_object, TypedArrayBase const& exemplar, MarkedValueList arguments) static TypedArrayBase* typed_array_species_create(GlobalObject& global_object, TypedArrayBase const& exemplar, MarkedValueList arguments)
{ {
@ -303,6 +333,34 @@ JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::find_index)
return Value(result_index); return Value(result_index);
} }
// 4 %TypedArray%.prototype.findLast ( predicate [ , thisArg ] ), https://tc39.es/proposal-array-find-from-last/index.html#sec-%typedarray%.prototype.findlast
JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::find_last)
{
auto result = js_undefined();
for_each_item_from_last(vm, global_object, "findLast", [&](auto, auto value, auto callback_result) {
if (callback_result.to_boolean()) {
result = value;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
return result;
}
// 5 %TypedArray%.prototype.findLastIndex ( predicate [ , thisArg ] ), https://tc39.es/proposal-array-find-from-last/index.html#sec-%typedarray%.prototype.findlastindex
JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::find_last_index)
{
auto result_index = -1;
for_each_item_from_last(vm, global_object, "findLastIndex", [&](auto index, auto, auto callback_result) {
if (callback_result.to_boolean()) {
result_index = index;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
return Value(result_index);
}
// 23.2.3.12 %TypedArray%.prototype.forEach ( callbackfn [ , thisArg ] ), https://tc39.es/ecma262/#sec-%typedarray%.prototype.foreach // 23.2.3.12 %TypedArray%.prototype.forEach ( callbackfn [ , thisArg ] ), https://tc39.es/ecma262/#sec-%typedarray%.prototype.foreach
JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::for_each) JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::for_each)
{ {

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@ -30,6 +30,8 @@ private:
JS_DECLARE_NATIVE_FUNCTION(fill); JS_DECLARE_NATIVE_FUNCTION(fill);
JS_DECLARE_NATIVE_FUNCTION(find); JS_DECLARE_NATIVE_FUNCTION(find);
JS_DECLARE_NATIVE_FUNCTION(find_index); JS_DECLARE_NATIVE_FUNCTION(find_index);
JS_DECLARE_NATIVE_FUNCTION(find_last);
JS_DECLARE_NATIVE_FUNCTION(find_last_index);
JS_DECLARE_NATIVE_FUNCTION(for_each); JS_DECLARE_NATIVE_FUNCTION(for_each);
JS_DECLARE_NATIVE_FUNCTION(includes); JS_DECLARE_NATIVE_FUNCTION(includes);
JS_DECLARE_NATIVE_FUNCTION(index_of); JS_DECLARE_NATIVE_FUNCTION(index_of);

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@ -0,0 +1,121 @@
const TYPED_ARRAYS = [
Uint8Array,
Uint8ClampedArray,
Uint16Array,
Uint32Array,
Int8Array,
Int16Array,
Int32Array,
Float32Array,
Float64Array,
];
const BIGINT_TYPED_ARRAYS = [BigUint64Array, BigInt64Array];
test("length is 1", () => {
TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLast).toHaveLength(1);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLast).toHaveLength(1);
});
});
describe("errors", () => {
function errorTests(T) {
test(`requires at least one argument (${T.name})`, () => {
expect(() => {
new T().findLast();
}).toThrowWithMessage(
TypeError,
"TypedArray.prototype.findLast() requires at least one argument"
);
});
test(`callback must be a function (${T.name})`, () => {
expect(() => {
new T().findLast(undefined);
}).toThrowWithMessage(TypeError, "undefined is not a function");
});
}
TYPED_ARRAYS.forEach(T => errorTests(T));
BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
});
describe("normal behaviour", () => {
test("basic functionality", () => {
TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1, 2, 3]);
expect(typedArray.findLast(value => value === 1)).toBe(1);
expect(typedArray.findLast(value => value === 2)).toBe(2);
expect(typedArray.findLast(value => value === 3)).toBe(3);
expect(typedArray.findLast((value, index) => index === 1)).toBe(2);
expect(typedArray.findLast(value => value == "1")).toBe(1);
expect(typedArray.findLast(value => value === 10)).toBeUndefined();
const typedArrayDuplicates = new T([2, 1, 2, 3, 1]);
expect(typedArrayDuplicates.findLast(value => value < 3)).toBe(1);
expect(typedArrayDuplicates.findLast(value => value < 2)).toBe(1);
expect(typedArrayDuplicates.findLast(value => value > 1)).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1n, 2n, 3n]);
expect(typedArray.findLast(value => value === 1n)).toBe(1n);
expect(typedArray.findLast(value => value === 2n)).toBe(2n);
expect(typedArray.findLast(value => value === 3n)).toBe(3n);
expect(typedArray.findLast((value, index) => index === 1)).toBe(2n);
expect(typedArray.findLast(value => value == 1)).toBe(1n);
expect(typedArray.findLast(value => value == "1")).toBe(1n);
expect(typedArray.findLast(value => value === 1)).toBeUndefined();
const typedArrayDuplicates = new T([2n, 1n, 2n, 3n, 1n]);
expect(typedArrayDuplicates.findLast(value => value < 3)).toBe(1n);
expect(typedArrayDuplicates.findLast(value => value < 2)).toBe(1n);
expect(typedArrayDuplicates.findLast(value => value > 1)).toBe(3n);
});
});
test("never calls callback with empty array", () => {
function emptyTest(T) {
var callbackCalled = 0;
expect(
new T().findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(0);
}
TYPED_ARRAYS.forEach(T => emptyTest(T));
BIGINT_TYPED_ARRAYS.forEach(T => emptyTest(T));
});
test("calls callback once for every item", () => {
TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1, 2, 3]).findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1n, 2n, 3n]).findLast(() => {
callbackCalled++;
})
).toBeUndefined();
expect(callbackCalled).toBe(3);
});
});
});

View file

@ -0,0 +1,121 @@
const TYPED_ARRAYS = [
Uint8Array,
Uint8ClampedArray,
Uint16Array,
Uint32Array,
Int8Array,
Int16Array,
Int32Array,
Float32Array,
Float64Array,
];
const BIGINT_TYPED_ARRAYS = [BigUint64Array, BigInt64Array];
test("length is 1", () => {
TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLastIndex).toHaveLength(1);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
expect(T.prototype.findLastIndex).toHaveLength(1);
});
});
describe("errors", () => {
function errorTests(T) {
test(`requires at least one argument (${T.name})`, () => {
expect(() => {
new T().findLastIndex();
}).toThrowWithMessage(
TypeError,
"TypedArray.prototype.findLastIndex() requires at least one argument"
);
});
test(`callback must be a function (${T.name})`, () => {
expect(() => {
new T().findLastIndex(undefined);
}).toThrowWithMessage(TypeError, "undefined is not a function");
});
}
TYPED_ARRAYS.forEach(T => errorTests(T));
BIGINT_TYPED_ARRAYS.forEach(T => errorTests(T));
});
describe("normal behaviour", () => {
test("basic functionality", () => {
TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1, 2, 3]);
expect(typedArray.findLastIndex(value => value === 1)).toBe(0);
expect(typedArray.findLastIndex(value => value === 2)).toBe(1);
expect(typedArray.findLastIndex(value => value === 3)).toBe(2);
expect(typedArray.findLastIndex((value, index) => index === 1)).toBe(1);
expect(typedArray.findLastIndex(value => value == "1")).toBe(0);
expect(typedArray.findLastIndex(value => value === 10)).toBe(-1);
const typedArrayDuplicates = new T([1, 2, 3, 1]);
expect(typedArrayDuplicates.findLastIndex(value => value === 1)).toBe(3);
expect(typedArrayDuplicates.findLastIndex(value => value === 2)).toBe(1);
expect(typedArrayDuplicates.findLastIndex(value => value === 3)).toBe(2);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
const typedArray = new T([1n, 2n, 3n]);
expect(typedArray.findLastIndex(value => value === 1n)).toBe(0);
expect(typedArray.findLastIndex(value => value === 2n)).toBe(1);
expect(typedArray.findLastIndex(value => value === 3n)).toBe(2);
expect(typedArray.findLastIndex((value, index) => index === 1)).toBe(1);
expect(typedArray.findLastIndex(value => value == 1)).toBe(0);
expect(typedArray.findLastIndex(value => value == "1")).toBe(0);
expect(typedArray.findLastIndex(value => value === 1)).toBe(-1);
const typedArrayDuplicates = new T([1n, 2n, 3n, 1n]);
expect(typedArrayDuplicates.findLastIndex(value => value === 1n)).toBe(3);
expect(typedArrayDuplicates.findLastIndex(value => value === 2n)).toBe(1);
expect(typedArrayDuplicates.findLastIndex(value => value === 3n)).toBe(2);
});
});
test("never calls callback with empty array", () => {
function emptyTest(T) {
var callbackCalled = 0;
expect(
new T().findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(0);
}
TYPED_ARRAYS.forEach(T => emptyTest(T));
BIGINT_TYPED_ARRAYS.forEach(T => emptyTest(T));
});
test("calls callback once for every item", () => {
TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1, 2, 3]).findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(3);
});
BIGINT_TYPED_ARRAYS.forEach(T => {
var callbackCalled = 0;
expect(
new T([1n, 2n, 3n]).findLastIndex(() => {
callbackCalled++;
})
).toBe(-1);
expect(callbackCalled).toBe(3);
});
});
});