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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 <LibJS/Interpreter.h>
#include <LibJS/Runtime/BoundFunction.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/FunctionObject.h>
namespace JS {
FunctionObject::FunctionObject(Object& prototype)
: Object(prototype)
{
}
FunctionObject::~FunctionObject()
{
}
// 10.2.9 SetFunctionName ( F, name [ , prefix ] ), https://tc39.es/ecma262/#sec-setfunctionname
void FunctionObject::set_function_name(Variant<PropertyKey, PrivateName> const& name_arg, Optional<StringView> const& prefix)
{
auto& vm = this->vm();
// 1. Assert: F is an extensible object that does not have a "name" own property.
VERIFY(m_is_extensible);
VERIFY(!storage_has(vm.names.name));
String name;
// 2. If Type(name) is Symbol, then
if (auto const* property_key = name_arg.get_pointer<PropertyKey>(); property_key && property_key->is_symbol()) {
// a. Let description be name's [[Description]] value.
auto const& description = property_key->as_symbol()->raw_description();
// b. If description is undefined, set name to the empty String.
if (!description.has_value())
name = String::empty();
// c. Else, set name to the string-concatenation of "[", description, and "]".
else
name = String::formatted("[{}]", *description);
}
// 3. Else if name is a Private Name, then
else if (auto const* private_name = name_arg.get_pointer<PrivateName>()) {
// a. Set name to name.[[Description]].
name = private_name->description;
}
// NOTE: This is necessary as we use a different parameter name.
else {
name = name_arg.get<PropertyKey>().to_string();
}
// 4. If F has an [[InitialName]] internal slot, then
if (is<NativeFunction>(this)) {
// a. Set F.[[InitialName]] to name.
// TODO: Remove FunctionObject::name(), implement NativeFunction::initial_name(), and then do this.
}
// 5. If prefix is present, then
if (prefix.has_value()) {
// a. Set name to the string-concatenation of prefix, the code unit 0x0020 (SPACE), and name.
name = String::formatted("{} {}", *prefix, name);
// b. If F has an [[InitialName]] internal slot, then
if (is<NativeFunction>(this)) {
// i. Optionally, set F.[[InitialName]] to name.
// TODO: See above.
}
}
// 6. Return ! DefinePropertyOrThrow(F, "name", PropertyDescriptor { [[Value]]: name, [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true }).
MUST(define_property_or_throw(vm.names.name, PropertyDescriptor { .value = js_string(vm, move(name)), .writable = false, .enumerable = false, .configurable = true }));
}
ThrowCompletionOr<BoundFunction*> FunctionObject::bind(Value bound_this_value, Vector<Value> arguments)
{
auto& vm = this->vm();
FunctionObject& target_function = is<BoundFunction>(*this) ? static_cast<BoundFunction&>(*this).bound_target_function() : *this;
auto get_bound_this_object = [&vm, bound_this_value, this]() -> ThrowCompletionOr<Value> {
if (is<BoundFunction>(*this) && !static_cast<BoundFunction&>(*this).bound_this().is_empty())
return static_cast<BoundFunction&>(*this).bound_this();
switch (bound_this_value.type()) {
case Value::Type::Undefined:
case Value::Type::Null:
if (vm.in_strict_mode())
return bound_this_value;
return &global_object();
default:
return TRY(bound_this_value.to_object(global_object()));
}
};
auto bound_this_object = TRY(get_bound_this_object());
i32 computed_length = 0;
auto length_property = TRY(get(vm.names.length));
if (length_property.is_number())
computed_length = max(0, length_property.as_i32() - static_cast<i32>(arguments.size()));
Object* constructor_prototype = nullptr;
auto prototype_property = TRY(target_function.get(vm.names.prototype));
if (prototype_property.is_object())
constructor_prototype = &prototype_property.as_object();
Vector<Value> all_bound_arguments;
if (is<BoundFunction>(*this))
all_bound_arguments.extend(static_cast<BoundFunction&>(*this).bound_arguments());
all_bound_arguments.extend(move(arguments));
return heap().allocate<BoundFunction>(global_object(), global_object(), target_function, bound_this_object, move(all_bound_arguments), computed_length, constructor_prototype);
}
}
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