Re: RFC: Support for multi-line arrow functions

Hey Nuno, <http://ocramius.github.com/> On Sat, Oct 3, 2020 at 11:09 PM Nuno Maduro <enunomaduro@gmail.com> wrote: > Hey internals, > > > A few days ago I opened a pull request that adds support for multi-line > arrow functions in PHP: > https://github.com/php/php-src/pull/6246. > > > As you may already know, PHP 7.4 has introduced one-liner arrow functions > (aka short closures). Now, this pull request adds the possibility of those > arrow functions to be multi-line. Just like in Javascript, or Hack. Let's > see an example: > > > ```php > > $users = [/** */]; > > $guestsIds = [/** */]; > > $repository = /** */; > > > $guests = array_filter($users, fn ($user) => { > > $guest = $repository->findByUserId($user->id); > > > return $guest !== null && in_array($guest->id, $guestsIds); > > }); > > ``` > > > In short, the advantages are: > > ``` > > $values = array_filter($values, function ($value) use ($first, $second, > $third) { > > // vs > > $values = array_filter($values, fn ($value) => { > > ``` > > > - Multi-line arrow functions don't require the use keyword > to be able to > access data from the outer scope. > > - Also, in some cases, fn (/** */) => { is just shorter and > simpler than > function (/** */) use (/** */) {. > > > This pull request has been very well received by the community on Github, > and also on Twitter: > https://twitter.com/enunomaduro/status/1311572174256340992. > > > So, I am writing this email to get your feedback about having this feature > in the core of PHP. Note that, if eventually, you think it is a good idea > to create an RFC on this, I will need to get some RFC karma - my wiki > account is nunomaduro. > Overall, seems like unnecessary added syntax for something that already works just fine. Pros: * unclear Cons: * more scope leak * +1 way to do what we already do just fine * more lexer/ast complexity for downstream projects If you want to make an RFC about it, it really needs a compelling "pros" section, because there aren't any, so far :-\ Greets, Marco Pivetta http://twitter.com/Ocramius http://ocramius.github.com/