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LibJS: Re-implement the Array Grouping proposal as static methods

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Closes #19495.
This commit is contained in:
Linus Groh 2023-07-11 16:23:00 +02:00
parent f418605ec7
commit 419e710c1c
10 changed files with 220 additions and 276 deletions
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47
Userland/Libraries/LibJS/Runtime/MapConstructor.cpp
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@ -1,12 +1,13 @@
/*
* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
* Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/IteratorOperations.h>
#include <LibJS/Runtime/Map.h>
#include <LibJS/Runtime/MapConstructor.h>
@ -26,6 +27,9 @@ ThrowCompletionOr<void> MapConstructor::initialize(Realm& realm)
// 24.1.2.1 Map.prototype, https://tc39.es/ecma262/#sec-map.prototype
define_direct_property(vm.names.prototype, realm.intrinsics().map_prototype(), 0);
u8 attr = Attribute::Writable | Attribute::Configurable;
define_native_function(realm, vm.names.groupBy, group_by, 2, attr);
define_native_accessor(realm, vm.well_known_symbol_species(), symbol_species_getter, {}, Attribute::Configurable);
define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
@ -68,6 +72,47 @@ ThrowCompletionOr<NonnullGCPtr<Object>> MapConstructor::construct(FunctionObject
return map;
}
// 3.1 Map.groupBy ( items, callbackfn ), https://tc39.es/proposal-array-grouping/#sec-map.groupby
JS_DEFINE_NATIVE_FUNCTION(MapConstructor::group_by)
{
auto& realm = *vm.current_realm();
auto items = vm.argument(0);
auto callback_function = vm.argument(1);
struct KeyedGroupTraits : public Traits<Handle<Value>> {
static unsigned hash(Handle<Value> const& value_handle)
{
return ValueTraits::hash(value_handle.value());
}
static bool equals(Handle<Value> const& a, Handle<Value> const& b)
{
// AddValueToKeyedGroup uses SameValue on the keys on Step 1.a.
return same_value(a.value(), b.value());
}
};
// 1. Let groups be ? GroupBy(items, callbackfn, zero).
auto groups = TRY((JS::group_by<OrderedHashMap<Handle<Value>, MarkedVector<Value>, KeyedGroupTraits>, void>(vm, items, callback_function)));
// 2. Let map be ! Construct(%Map%).
auto map = Map::create(realm);
// 3. For each Record { [[Key]], [[Elements]] } g of groups, do
for (auto& group : groups) {
// a. Let elements be CreateArrayFromList(g.[[Elements]]).
auto elements = Array::create_from(realm, group.value);
// b. Let entry be the Record { [[Key]]: g.[[Key]], [[Value]]: elements }.
// c. Append entry to map.[[MapData]].
map->map_set(group.key.value(), elements);
}
// 4. Return map.
return map;
}
// 24.1.2.2 get Map [ @@species ], https://tc39.es/ecma262/#sec-get-map-@@species
JS_DEFINE_NATIVE_FUNCTION(MapConstructor::symbol_species_getter)
{