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Date: Wed, 24 Mar 2021 21:26:18 +0000
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Subject: Re: [PHP-DEV] [RFC] Auto-capture multi-line closures and
 shortfunctions take 2
From: marandall@php.net (Mark Randall)
Message-ID: <php.internals-113747@news.php.net>

On 24/03/2021 21:00, Rowan Tommins wrote:
> As Christian says, automatic capture is a dramatic change to the 
> language's scoping rules, and IMHO requires a more thorough 
> justification on why the current syntax is burdensome. As I've said 
> previously, my naive impression is that a long list of captured 
> variables ought to be as bad a code smell as a long list of parameters; 
> I'm willing to be proven wrong on this, but nobody has yet stepped 
> forward with a real-life example.

Automatic capture ceased to be a dramatic change from PHP the day after 
short closurers were introduced. So they've been a part of PHP for years 
now.

I hit long lists of use() repeatedly, almost always because I need to 
perform a series of operations within a callback, prime examples are 
database transactions and using throw-aware buffering handlers.

In general, anything that needs to wrap a code block in a complex set of 
instructions before and after.

To give my own example, earlier this week I wrote the following:

$x = function () use ($to, $library, $thread, $author, $title, 
$library_name, $top_post) { ... }

That was just to get those variables inside a callback that could be 
invoked inside a throw-aware buffering helper.

I believe that by explicitly stating my intent to use auto capture by 
using fn() { ... } that my code would have been cleaner with less noise.

If I thought otherwise, I would be under no obligation to use them and 
could use function() { ... } instead.

For me auto capture is a solid +1.

Mark Randall