ladybird/Userland/Libraries/LibJS/Runtime/Array.cpp
Linus Groh 7327a28ccc LibJS: Add ECMA-262 section/title/URL comments almost everywhere
As mentioned on Discord earlier, we'll add these to all new functions
going forward - this is the backfill. Reasons:

- It makes you look at the spec, implementing based on MDN or V8
  behavior is a no-go
- It makes finding the various functions that are non-compliant easier,
  in the future everything should either have such a comment or, if it's
  not from the spec at all, a comment explaining why that is the case
- It makes it easier to check whether a certain abstract operation is
  implemented in LibJS, not all of them use the same name as the spec.
  E.g. RejectPromise() is Promise::reject()
- It makes it easier to reason about vm.arguments(), e.g. when the
  function has a rest parameter
- It makes it easier to see whether a certain function is from a
  proposal or Annex B

Also:

- Add arguments to all functions and abstract operations that already
  had a comment
- Fix some outdated section numbers
- Replace some ecma-international.org URLs with tc39.es
2021-06-13 00:33:28 +01:00

89 lines
2.6 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Function.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GlobalObject.h>
namespace JS {
// 10.4.2.2 ArrayCreate ( length [ , proto ] ), https://tc39.es/ecma262/#sec-arraycreate
Array* Array::create(GlobalObject& global_object, size_t length)
{
// FIXME: Support proto parameter
if (length > NumericLimits<u32>::max()) {
auto& vm = global_object.vm();
vm.throw_exception<RangeError>(global_object, ErrorType::InvalidLength, "array");
return nullptr;
}
auto* array = global_object.heap().allocate<Array>(global_object, *global_object.array_prototype());
array->indexed_properties().set_array_like_size(length);
return array;
}
// 7.3.17 CreateArrayFromList ( elements ), https://tc39.es/ecma262/#sec-createarrayfromlist
Array* Array::create_from(GlobalObject& global_object, const Vector<Value>& elements)
{
auto* array = Array::create(global_object);
for (size_t i = 0; i < elements.size(); ++i)
array->define_property(i, elements[i]);
return array;
}
Array::Array(Object& prototype)
: Object(prototype)
{
}
void Array::initialize(GlobalObject& global_object)
{
auto& vm = this->vm();
Object::initialize(global_object);
define_native_property(vm.names.length, length_getter, length_setter, Attribute::Writable);
}
Array::~Array()
{
}
Array* Array::typed_this(VM& vm, GlobalObject& global_object)
{
auto* this_object = vm.this_value(global_object).to_object(global_object);
if (!this_object)
return {};
if (!this_object->is_array()) {
vm.throw_exception<TypeError>(global_object, ErrorType::NotAn, "Array");
return nullptr;
}
return static_cast<Array*>(this_object);
}
JS_DEFINE_NATIVE_GETTER(Array::length_getter)
{
auto* array = typed_this(vm, global_object);
if (!array)
return {};
return Value(array->indexed_properties().array_like_size());
}
JS_DEFINE_NATIVE_SETTER(Array::length_setter)
{
auto* array = typed_this(vm, global_object);
if (!array)
return;
auto length = value.to_number(global_object);
if (vm.exception())
return;
if (length.is_nan() || length.is_infinity() || length.as_double() < 0) {
vm.throw_exception<RangeError>(global_object, ErrorType::InvalidLength, "array");
return;
}
array->indexed_properties().set_array_like_size(length.as_double());
}
}