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LibJS: Add TypedArraySpeciesCreate and %TypedArray%.prototype.filter

I'm not too happy with how I get the default constructor in
typed_array_species_create, but it works for now.
This commit is contained in:
Luke 2021-07-09 06:20:45 +01:00 committed by Linus Groh
parent 53bc3f8e3b
commit bc6f619344
3 changed files with 323 additions and 0 deletions

View file

@ -47,6 +47,7 @@ void TypedArrayPrototype::initialize(GlobalObject& object)
define_native_function(vm.names.set, set, 1, attr);
define_native_function(vm.names.reverse, reverse, 0, attr);
define_native_function(vm.names.copyWithin, copy_within, 2, attr);
define_native_function(vm.names.filter, filter, 1, attr);
define_native_accessor(*vm.well_known_symbol_to_string_tag(), to_string_tag_getter, nullptr, Attribute::Configurable);
@ -118,6 +119,38 @@ static void for_each_item(VM& vm, GlobalObject& global_object, const String& nam
}
}
// 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)
{
auto& vm = global_object.vm();
TypedArrayConstructor* typed_array_default_constructor = nullptr;
// FIXME: This kinda sucks.
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, Type) \
if (is<ClassName>(exemplar)) \
typed_array_default_constructor = global_object.snake_name##_constructor();
JS_ENUMERATE_TYPED_ARRAYS
#undef __JS_ENUMERATE
VERIFY(typed_array_default_constructor);
auto* constructor = species_constructor(global_object, exemplar, *typed_array_default_constructor);
if (vm.exception())
return nullptr;
auto* result = typed_array_create(global_object, *constructor, move(arguments));
if (vm.exception())
return nullptr;
if (result->content_type() != exemplar.content_type()) {
vm.throw_exception<TypeError>(global_object, ErrorType::TypedArrayContentTypeMismatch, result->class_name(), exemplar.class_name());
return nullptr;
}
return result;
}
// 23.2.3.18 get %TypedArray%.prototype.length, https://tc39.es/ecma262/#sec-get-%typedarray%.prototype.length
JS_DEFINE_NATIVE_GETTER(TypedArrayPrototype::length_getter)
{
@ -991,4 +1024,76 @@ JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::copy_within)
return typed_array;
}
// 23.2.3.9 %TypedArray%.prototype.filter ( callbackfn [ , thisArg ] ), https://tc39.es/ecma262/#sec-%typedarray%.prototype.filter
JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::filter)
{
// 1. Let O be the this value.
// 2. Perform ? ValidateTypedArray(O).
auto* typed_array = typed_array_from(vm, global_object);
if (!typed_array)
return {};
// 3. Let len be O.[[ArrayLength]].
auto initial_length = typed_array->array_length();
// 4. If IsCallable(callbackfn) is false, throw a TypeError exception.
auto* callback_function = callback_from_args(global_object, "filter");
if (!callback_function)
return {};
// 5. Let kept be a new empty List.
MarkedValueList kept(vm.heap());
// 7. Let captured be 0.
size_t captured = 0;
auto this_value = vm.argument(1);
// 5. Let k be 0.
// 8. Repeat, while k < len,
for (size_t i = 0; i < initial_length; ++i) {
// a. Let Pk be ! ToString(𝔽(k)).
// b. Let kValue be ! Get(O, Pk).
auto value = typed_array->get(i);
// c. Let selected be ! ToBoolean(? Call(callbackfn, thisArg, « kValue, 𝔽(k), O »)).
auto callback_result = vm.call(*callback_function, this_value, value, Value((i32)i), typed_array);
if (vm.exception())
return {};
// d. If selected is true, then
if (callback_result.to_boolean()) {
// i. Append kValue to the end of kept.
kept.append(value);
// ii. Set captured to captured + 1.
++captured;
}
// e. Set k to k + 1.
}
// 9. Let A be ? TypedArraySpeciesCreate(O, « 𝔽(captured) »).
MarkedValueList arguments(vm.heap());
arguments.empend(captured);
auto* filter_array = typed_array_species_create(global_object, *typed_array, move(arguments));
if (vm.exception())
return {};
// 10. Let n be 0.
size_t index = 0;
// 11. For each element e of kept, do
for (auto& value : kept) {
// a. Perform ! Set(A, ! ToString(𝔽(n)), e, true).
filter_array->set(index, value, true);
// b. Set n to n + 1.
++index;
}
// 12. Return A.
return filter_array;
}
}

View file

@ -44,6 +44,7 @@ private:
JS_DECLARE_NATIVE_FUNCTION(set);
JS_DECLARE_NATIVE_FUNCTION(reverse);
JS_DECLARE_NATIVE_FUNCTION(copy_within);
JS_DECLARE_NATIVE_FUNCTION(filter);
};
}