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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Utf16View.h>
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/PrimitiveString.h>
#include <LibJS/Runtime/PropertyDescriptor.h>
#include <LibJS/Runtime/StringObject.h>
namespace JS {
// 10.4.3.4 StringCreate ( value, prototype ), https://tc39.es/ecma262/#sec-stringcreate
StringObject* StringObject::create(Realm& realm, PrimitiveString& primitive_string, Object& prototype)
{
return realm.heap().allocate<StringObject>(realm, primitive_string, prototype);
}
StringObject::StringObject(PrimitiveString& string, Object& prototype)
: Object(prototype)
, m_string(string)
{
}
void StringObject::initialize(Realm& realm)
{
auto& vm = this->vm();
Object::initialize(realm);
define_direct_property(vm.names.length, Value(m_string.utf16_string_view().length_in_code_units()), 0);
}
void StringObject::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(&m_string);
}
// 10.4.3.5 StringGetOwnProperty ( S, P ), https://tc39.es/ecma262/#sec-stringgetownproperty
static Optional<PropertyDescriptor> string_get_own_property(StringObject const& string, PropertyKey const& property_key)
{
VERIFY(property_key.is_valid());
// 1. If Type(P) is not String, return undefined.
// NOTE: The spec only uses string and symbol keys, and later coerces to numbers -
// this is not the case for PropertyKey, so '!property_key.is_string()' would be wrong.
if (property_key.is_symbol())
return {};
// 2. Let index be CanonicalNumericIndexString(P).
auto index = canonical_numeric_index_string(property_key, CanonicalIndexMode::IgnoreNumericRoundtrip);
// 3. If index is undefined, return undefined.
// 4. If IsIntegralNumber(index) is false, return undefined.
// 5. If index is -0𝔽, return undefined.
if (!index.is_index())
return {};
// 6. Let str be S.[[StringData]].
// 7. Assert: Type(str) is String.
auto str = string.primitive_string().utf16_string_view();
// 8. Let len be the length of str.
auto length = str.length_in_code_units();
// 9. If ℝ(index) < 0 or len ≤ ℝ(index), return undefined.
if (length <= index.as_index())
return {};
// 10. Let resultStr be the String value of length 1, containing one code unit from str, specifically the code unit at index ℝ(index).
auto result_str = js_string(string.vm(), str.substring_view(index.as_index(), 1));
// 11. Return the PropertyDescriptor { [[Value]]: resultStr, [[Writable]]: false, [[Enumerable]]: true, [[Configurable]]: false }.
return PropertyDescriptor {
.value = result_str,
.writable = false,
.enumerable = true,
.configurable = false,
};
}
// 10.4.3.1 [[GetOwnProperty]] ( P ), https://tc39.es/ecma262/#sec-string-exotic-objects-getownproperty-p
ThrowCompletionOr<Optional<PropertyDescriptor>> StringObject::internal_get_own_property(PropertyKey const& property_key) const
{
VERIFY(property_key.is_valid());
// 1. Let desc be OrdinaryGetOwnProperty(S, P).
auto descriptor = MUST(Object::internal_get_own_property(property_key));
// 2. If desc is not undefined, return desc.
if (descriptor.has_value())
return descriptor;
// 3. Return StringGetOwnProperty(S, P).
return string_get_own_property(*this, property_key);
}
// 10.4.3.2 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-string-exotic-objects-defineownproperty-p-desc
ThrowCompletionOr<bool> StringObject::internal_define_own_property(PropertyKey const& property_key, PropertyDescriptor const& property_descriptor)
{
VERIFY(property_key.is_valid());
// 1. Let stringDesc be StringGetOwnProperty(S, P).
auto string_descriptor = string_get_own_property(*this, property_key);
// 2. If stringDesc is not undefined, then
if (string_descriptor.has_value()) {
// a. Let extensible be S.[[Extensible]].
auto extensible = m_is_extensible;
// b. Return IsCompatiblePropertyDescriptor(extensible, Desc, stringDesc).
return is_compatible_property_descriptor(extensible, property_descriptor, string_descriptor);
}
// 3. Return ! OrdinaryDefineOwnProperty(S, P, Desc).
return Object::internal_define_own_property(property_key, property_descriptor);
}
// 10.4.3.3 [[OwnPropertyKeys]] ( ), https://tc39.es/ecma262/#sec-string-exotic-objects-ownpropertykeys
ThrowCompletionOr<MarkedVector<Value>> StringObject::internal_own_property_keys() const
{
auto& vm = this->vm();
// 1. Let keys be a new empty List.
auto keys = MarkedVector<Value> { heap() };
// 2. Let str be O.[[StringData]].
auto str = m_string.utf16_string_view();
// 3. Assert: Type(str) is String.
// 4. Let len be the length of str.
auto length = str.length_in_code_units();
// 5. For each integer i starting with 0 such that i < len, in ascending order, do
for (size_t i = 0; i < length; ++i) {
// a. Add ! ToString(𝔽(i)) as the last element of keys.
keys.append(js_string(vm, String::number(i)));
}
// 6. For each own property key P of O such that P is an array index and ! ToIntegerOrInfinity(P) ≥ len, in ascending numeric index order, do
for (auto& entry : indexed_properties()) {
if (entry.index() >= length) {
// a. Add P as the last element of keys.
keys.append(js_string(vm, String::number(entry.index())));
}
}
// 7. For each own property key P of O such that Type(P) is String and P is not an array index, in ascending chronological order of property creation, do
for (auto& it : shape().property_table_ordered()) {
if (it.key.is_string()) {
// a. Add P as the last element of keys.
keys.append(it.key.to_value(vm));
}
}
// 8. For each own property key P of O such that Type(P) is Symbol, in ascending chronological order of property creation, do
for (auto& it : shape().property_table_ordered()) {
if (it.key.is_symbol()) {
// a. Add P as the last element of keys.
keys.append(it.key.to_value(vm));
}
}
// 9. Return keys.
return { move(keys) };
}
}
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