Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:111991
MIME-Version: 1.0
Date: Sat, 3 Oct 2020 23:09:38 +0200
Message-ID: <CALZWoqU_qQQiQ5O6Pa8Upxo2FYZ2hpMA0dy9=CZndeEFsijgxA@mail.gmail.com>
To: internals@lists.php.net
Content-Type: multipart/alternative; boundary="00000000000069b53105b0caabaa"
Subject: RFC: Support for multi-line arrow functions
From: enunomaduro@gmail.com (Nuno Maduro)

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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.


Regards,

Nuno - https://twitter.com/enunomaduro.

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