4699c81fc1
This patch makes IteratorRecord an Object. Although it's not exposed to
author code, this does allow us to store it in a VM register.
Now that we can store it in a VM register, we don't need to convert it
back and forth between IteratorRecord and Object when accessing it from
bytecode.
The big win here is avoiding 3 [[Get]] accesses on every iteration step
of for..of loops. There are also a bunch of smaller efficiencies gained.
20% speed-up on this microbenchmark:
function go(a) {
for (const p of a) {
}
}
const a = [];
a.length = 1_000_000;
go(a);
89 lines
3 KiB
C++
89 lines
3 KiB
C++
/*
|
|
* Copyright (c) 2020, Matthew Olsson <mattco@serenityos.org>
|
|
* Copyright (c) 2022-2023, Linus Groh <linusg@serenityos.org>
|
|
* Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Function.h>
|
|
#include <AK/Optional.h>
|
|
#include <LibJS/Runtime/Completion.h>
|
|
#include <LibJS/Runtime/Object.h>
|
|
#include <LibJS/Runtime/Value.h>
|
|
|
|
namespace JS {
|
|
|
|
// 7.4.1 Iterator Records, https://tc39.es/ecma262/#sec-iterator-records
|
|
class IteratorRecord final : public Object {
|
|
JS_OBJECT(IteratorRecord, Object);
|
|
JS_DECLARE_ALLOCATOR(IteratorRecord);
|
|
|
|
public:
|
|
IteratorRecord(Realm& realm, GCPtr<Object> iterator, Value next_method, bool done)
|
|
: Object(ConstructWithoutPrototypeTag::Tag, realm)
|
|
, iterator(iterator)
|
|
, next_method(next_method)
|
|
, done(done)
|
|
{
|
|
}
|
|
|
|
GCPtr<Object> iterator; // [[Iterator]]
|
|
Value next_method; // [[NextMethod]]
|
|
bool done { false }; // [[Done]]
|
|
|
|
private:
|
|
virtual void visit_edges(Cell::Visitor&) override;
|
|
virtual bool is_iterator_record() const override { return true; }
|
|
};
|
|
|
|
template<>
|
|
inline bool Object::fast_is<IteratorRecord>() const { return is_iterator_record(); }
|
|
|
|
class Iterator : public Object {
|
|
JS_OBJECT(Iterator, Object);
|
|
JS_DECLARE_ALLOCATOR(Iterator);
|
|
|
|
public:
|
|
static NonnullGCPtr<Iterator> create(Realm&, Object& prototype, NonnullGCPtr<IteratorRecord> iterated);
|
|
|
|
IteratorRecord const& iterated() const { return m_iterated; }
|
|
|
|
private:
|
|
Iterator(Object& prototype, NonnullGCPtr<IteratorRecord> iterated);
|
|
explicit Iterator(Object& prototype);
|
|
|
|
virtual void visit_edges(Cell::Visitor&) override;
|
|
|
|
NonnullGCPtr<IteratorRecord> m_iterated; // [[Iterated]]
|
|
};
|
|
|
|
enum class IteratorHint {
|
|
Sync,
|
|
Async,
|
|
};
|
|
|
|
enum class StringHandling {
|
|
IterateStrings,
|
|
RejectStrings,
|
|
};
|
|
|
|
ThrowCompletionOr<NonnullGCPtr<IteratorRecord>> get_iterator_from_method(VM&, Value, NonnullGCPtr<FunctionObject>);
|
|
ThrowCompletionOr<NonnullGCPtr<IteratorRecord>> get_iterator(VM&, Value, IteratorHint);
|
|
ThrowCompletionOr<NonnullGCPtr<IteratorRecord>> get_iterator_direct(VM&, Object&);
|
|
ThrowCompletionOr<NonnullGCPtr<IteratorRecord>> get_iterator_flattenable(VM&, Value, StringHandling);
|
|
ThrowCompletionOr<NonnullGCPtr<Object>> iterator_next(VM&, IteratorRecord const&, Optional<Value> = {});
|
|
ThrowCompletionOr<GCPtr<Object>> iterator_step(VM&, IteratorRecord const&);
|
|
ThrowCompletionOr<bool> iterator_complete(VM&, Object& iterator_result);
|
|
ThrowCompletionOr<Value> iterator_value(VM&, Object& iterator_result);
|
|
Completion iterator_close(VM&, IteratorRecord const&, Completion);
|
|
Completion async_iterator_close(VM&, IteratorRecord const&, Completion);
|
|
NonnullGCPtr<Object> create_iterator_result_object(VM&, Value, bool done);
|
|
ThrowCompletionOr<MarkedVector<Value>> iterator_to_list(VM&, IteratorRecord const&);
|
|
|
|
using IteratorValueCallback = Function<Optional<Completion>(Value)>;
|
|
Completion get_iterator_values(VM&, Value iterable, IteratorValueCallback callback);
|
|
|
|
}
|