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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#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(GlobalObject& global_object, PrimitiveString& primitive_string, Object& prototype)
{
return global_object.heap().allocate<StringObject>(global_object, primitive_string, prototype);
}
StringObject::StringObject(PrimitiveString& string, Object& prototype)
: Object(prototype)
, m_string(string)
{
}
StringObject::~StringObject()
{
}
void StringObject::initialize(GlobalObject& global_object)
{
auto& vm = this->vm();
Object::initialize(global_object);
define_property(vm.names.length, Value(m_string.string().length()), 0);
}
void StringObject::visit_edges(Cell::Visitor& visitor)
{
Object::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(GlobalObject& global_object, StringObject const& string, PropertyName const& property_name)
{
auto& vm = global_object.vm();
// 1. Assert: S is an Object that has a [[StringData]] internal slot.
// 2. Assert: IsPropertyKey(P) is true.
VERIFY(property_name.is_valid());
// 3. 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 PropertyName, so '!property_name.is_string()' would be wrong.
if (property_name.is_symbol())
return {};
// 4. Let index be ! CanonicalNumericIndexString(P).
// NOTE: If the property name is a number type (An implementation-defined optimized
// property key type), it can be treated as a string property that has already been
// converted successfully into a canonical numeric index.
Value index;
if (property_name.is_string())
index = canonical_numeric_index_string(global_object, property_name.to_value(vm));
else
index = Value(property_name.as_number());
// 5. If index is undefined, return undefined.
if (index.is_undefined())
return {};
// 6. If IsIntegralNumber(index) is false, return undefined.
if (!index.is_integral_number())
return {};
// 7. If index is -0𝔽, return undefined.
if (index.is_negative_zero())
return {};
// 8. Let str be S.[[StringData]].
// 9. Assert: Type(str) is String.
auto& str = string.primitive_string().string();
// 10. Let len be the length of str.
auto length = str.length();
// 11. If ℝ(index) < 0 or len ≤ ℝ(index), return undefined.
if (index.as_double() < 0 || length <= index.as_double())
return {};
// 12. 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(index.as_double(), 1));
// 13. 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
Optional<PropertyDescriptor> StringObject::internal_get_own_property(PropertyName const& property_name) const
{
// Assert: IsPropertyKey(P) is true.
// 2. Let desc be OrdinaryGetOwnProperty(S, P).
auto descriptor = Object::internal_get_own_property(property_name);
// 3. If desc is not undefined, return desc.
if (descriptor.has_value())
return descriptor;
// 4. Return ! StringGetOwnProperty(S, P).
return string_get_own_property(global_object(), *this, property_name);
}
// 10.4.3.2 [[DefineOwnProperty]] ( P, Desc ), https://tc39.es/ecma262/#sec-string-exotic-objects-defineownproperty-p-desc
bool StringObject::internal_define_own_property(PropertyName const& property_name, PropertyDescriptor const& property_descriptor)
{
// 1. Assert: IsPropertyKey(P) is true.
VERIFY(property_name.is_valid());
// 2. Let stringDesc be ! StringGetOwnProperty(S, P).
auto string_descriptor = string_get_own_property(global_object(), *this, property_name);
// 3. 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);
}
// 4. Return ! OrdinaryDefineOwnProperty(S, P, Desc).
return Object::internal_define_own_property(property_name, property_descriptor);
}
// 10.4.3.3 [[OwnPropertyKeys]] ( ), https://tc39.es/ecma262/#sec-string-exotic-objects-ownpropertykeys
MarkedValueList StringObject::internal_own_property_keys() const
{
auto& vm = this->vm();
// 1. Let keys be a new empty List.
auto keys = MarkedValueList { heap() };
// 2. Let str be O.[[StringData]].
auto& str = m_string.string();
// 3. Assert: Type(str) is String.
// 4. Let len be the length of str.
auto length = str.length();
// 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 keys;
}
}
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