beenull/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-11-21 23:20:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6
ladybird/AK/Try.h

19 lines
607 B
C
Raw Normal View History

AK: Add a TRY(expression) macro to simplify the unwrap-or-return pattern The way we use classes like Kernel::KResultOr<T> and AK::Result<T, E> makes checking for errors (and short-circuiting returns) quite verbose. This patch adds a new TRY(expression) macro that either evaluates to the released result of the expression if successful, or returns the error if not. Before: auto foo_or_error = get_foo(); if (foo_or_error.is_error()) return foo_or_error.release_error(); auto foo = foo_or_error.release_value(); After: auto foo = TRY(get_foo()); The macro uses a GNU C++ extension which is supported by GCC, Clang, Intel C++, and possibly others. It's not *ideal*, but since it makes our codebase considerably nicer, let's try(!) it out. :^) Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
2021-09-05 11:32:15 +00:00
/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
// NOTE: This macro works with any result type that has the expected APIs.
Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T> We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace! This was a slightly tedious refactoring that took a long time, so it's not unlikely that some bugs crept in. Nevertheless, it does pass basic functionality testing, and it's just real nice to finally see the same pattern in all contexts. :^)
2021-11-07 23:51:39 +00:00
// It's designed with AK::Result and AK::Error in mind.
AK: Add a TRY(expression) macro to simplify the unwrap-or-return pattern The way we use classes like Kernel::KResultOr<T> and AK::Result<T, E> makes checking for errors (and short-circuiting returns) quite verbose. This patch adds a new TRY(expression) macro that either evaluates to the released result of the expression if successful, or returns the error if not. Before: auto foo_or_error = get_foo(); if (foo_or_error.is_error()) return foo_or_error.release_error(); auto foo = foo_or_error.release_value(); After: auto foo = TRY(get_foo()); The macro uses a GNU C++ extension which is supported by GCC, Clang, Intel C++, and possibly others. It's not *ideal*, but since it makes our codebase considerably nicer, let's try(!) it out. :^) Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
2021-09-05 11:32:15 +00:00
AK: Rename the local variable in the TRY() macro to avoid name clashes "result" is a tad bit too generic to provide a clash-free experience - we found instances in LibJS where this breaks already. Essentially this doesn't work: auto foo = TRY(bar(result)); Because it expands to the following within the TRY() scope: { auto result = bar(result); ... } And that of course fails: error: use of ‘result’ before deduction of ‘auto’ The simple solution here is to use a name that is much less likely to clash with anything used in the expression ("_temporary_result"). :^)
2021-09-15 21:57:05 +00:00
#define TRY(expression) \
({ \
auto _temporary_result = (expression); \
if (_temporary_result.is_error()) \
return _temporary_result.release_error(); \
_temporary_result.release_value(); \
AK: Add a TRY(expression) macro to simplify the unwrap-or-return pattern The way we use classes like Kernel::KResultOr<T> and AK::Result<T, E> makes checking for errors (and short-circuiting returns) quite verbose. This patch adds a new TRY(expression) macro that either evaluates to the released result of the expression if successful, or returns the error if not. Before: auto foo_or_error = get_foo(); if (foo_or_error.is_error()) return foo_or_error.release_error(); auto foo = foo_or_error.release_value(); After: auto foo = TRY(get_foo()); The macro uses a GNU C++ extension which is supported by GCC, Clang, Intel C++, and possibly others. It's not *ideal*, but since it makes our codebase considerably nicer, let's try(!) it out. :^) Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
2021-09-05 11:32:15 +00:00
})
Reference in a new issue Copy permalink