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LibJS: Add %TypedArray%.prototype.map

This commit is contained in:
Luke 2021-07-09 06:21:17 +01:00 committed by Linus Groh
parent bc6f619344
commit 1da06f9dfd
3 changed files with 311 additions and 0 deletions

View file

@ -48,6 +48,7 @@ void TypedArrayPrototype::initialize(GlobalObject& object)
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_function(vm.names.map, map, 1, attr);
define_native_accessor(*vm.well_known_symbol_to_string_tag(), to_string_tag_getter, nullptr, Attribute::Configurable);
@ -1096,4 +1097,54 @@ JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::filter)
return filter_array;
}
// 23.2.3.19 %TypedArray%.prototype.map ( callbackfn [ , thisArg ] ), https://tc39.es/ecma262/#sec-%typedarray%.prototype.map
JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::map)
{
// 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, "map");
if (!callback_function)
return {};
// 5. Let A be ? TypedArraySpeciesCreate(O, « 𝔽(len) »).
MarkedValueList arguments(vm.heap());
arguments.empend(initial_length);
auto* return_array = typed_array_species_create(global_object, *typed_array, move(arguments));
if (vm.exception())
return {};
auto this_value = vm.argument(1);
// 6. Let k be 0.
// 7. 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 mappedValue be ? Call(callbackfn, thisArg, « kValue, 𝔽(k), O »).
auto mapped_value = vm.call(*callback_function, this_value, value, Value((i32)i), typed_array);
if (vm.exception())
return {};
// d. Perform ? Set(A, Pk, mappedValue, true).
return_array->set(i, mapped_value, true);
if (vm.exception())
return {};
// e. Set k to k + 1.
}
// 8. Return A.
return return_array;
}
}

View file

@ -45,6 +45,7 @@ private:
JS_DECLARE_NATIVE_FUNCTION(reverse);
JS_DECLARE_NATIVE_FUNCTION(copy_within);
JS_DECLARE_NATIVE_FUNCTION(filter);
JS_DECLARE_NATIVE_FUNCTION(map);
};
}