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Date: Fri, 24 Nov 2023 11:26:54 +0100
Message-ID: <CABdc3WrJUXLhV1oyT+g5Ted9vH8AchCio5NuT=P=gONLM5U0bw@mail.gmail.com>
To: Robert Landers <landers.robert@gmail.com>
Cc: chopins xiao <chopins.xiao@gmail.com>, 
	"internals@lists.php.net" <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Is it possible to add asynchronous loop call function ?
From: michal.brzuchalski@gmail.com (=?UTF-8?Q?Micha=C5=82_Marcin_Brzuchalski?=)

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Hi Robert,

pt., 24 lis 2023 o 10:24 Robert Landers <landers.robert@gmail.com>
napisa=C5=82(a):

> ...
> You can also emulate this with:
>
> class Defer {
>   private function __construct(private \Closure $callback) {}
>   public function __destruct() { $this->callback(); }
>   public static function _(\Closure $callback) { return new
> self($callback); }
> }
>
> and use it like:
>
> function writeSomeStuff() {
>   // open files
>   $deferred =3D Defer::_($closeFiles(...));
>   // do stuff
> }
>
> So long as a reference exists to $deferred variable, the deferred
> method won't be run. If the variable is local to the method/function
> being run it, the deconstructor will be called after the function
> returns.
>
> It isn't the most beautiful thing in the world, and easy to forget to
> store the result of Defer, but it is handy sometimes.
>

This is interesting which makes me thinking if forget to store it could be
prevented.
I think requiring a ref could help with that:

class Defer {
  private function __construct(private \Closure $callback) {}
  public function __destruct() { ($this->callback)(); }
  public static function _(\Closure $callback, &$var) { $var =3D new
self($callback); }
}

$deferred =3D Defer::_($closeFiles(...), $foo);

Without $foo there'd be an ArgumentCountError.

Cheers,
Micha=C5=82 Marcin Brzuchalski

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