ladybird/Userland/Libraries/LibJS/Runtime/FunctionObject.cpp

61 lines
2.1 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Interpreter.h>
#include <LibJS/Runtime/BoundFunction.h>
#include <LibJS/Runtime/FunctionObject.h>
#include <LibJS/Runtime/GlobalObject.h>
namespace JS {
FunctionObject::FunctionObject(Object& prototype)
: Object(prototype)
{
}
FunctionObject::~FunctionObject()
{
}
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_OR_DISCARD(get_bound_this_object());
i32 computed_length = 0;
auto length_property = TRY_OR_DISCARD(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_OR_DISCARD(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);
}
}