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Date: Mon, 5 Oct 2020 11:57:31 +0200
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Subject: Re: [PHP-DEV] RFC: Support for multi-line arrow functions
From: a.leathley@gmx.net (Andreas Leathley)

On 04.10.20 22:08, Rowan Tommins wrote:
> If we added an opt-in syntax for "capture everything", we might
> instead write this:
>
> $f =3D function() use (*) {
> =C2=A0=C2=A0=C2=A0=C2=A0 $x =3D $y =3D $z =3D null;
> }
>
> Without re-initialising all local variables, we would no longer be
> able to know if they were actually local without looking at the
> surrounding scope for a value that might be captured. I am unconvinced
> by this trade-off of opt-out instead of opt-in.
>
> One use case I've seen proposed is closures which capture a large
> number of variables; I would be interested to see an example where
> this is the case and is not a "code smell" in the same way as
> requiring a large number of parameters.

Something like "use (*)" seems like a great enhancement to me. I often
use a wrapper function for SQL transactions, something like:

```php
public function update(int $numberId, int $addressId, bool $isMainNumber
=3D false): void
{
 =C2=A0=C2=A0=C2=A0 $this->transaction->run(function () use ($numberId, $a=
ddressId,
$isMainNumber): void {
 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 // Do all SQL queries for the update
 =C2=A0=C2=A0=C2=A0 });
}

```

In these cases there is a lot of redundancy because of having to import
the variables, and if a variable is added, it has to be added in two
places in a slightly different way. The following would be much nicer:

```php
public function update(int $numberId, int $addressId, bool $isMainNumber
=3D false): void
{
 =C2=A0=C2=A0=C2=A0 $this->transaction->run(function () use (*): void {
 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 // Do all SQL queries for the update
 =C2=A0=C2=A0=C2=A0 });
}

```

This would also increase code readability.