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Date: Tue, 1 Apr 2025 13:18:05 +1300
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Subject: Re: [PHP-DEV] Closure::getCurrent() for recursion
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From: weedpacket@varteg.nz (Morgan)


On 2025-04-01 09:38, Ilija Tovilo wrote:
 > Hi everyone
 >
 >
 > This is essentially already possible through a by-reference capture.
 >
 > $fibonacci = function (int $n) use (&$fibonacci) { ... };
 >
 > This cannot be a by-value capture because by the time the closure is
 > created and variables are bound, $fibonacci is not assigned yet. The
 > downside of by-reference capturing is that if $fibonacci is
 > accidentally reassigned, the reference within the closure is also
 > changed.
 >
 > However, I consider a language change largely unnecessary. Instead,
 > this may be solved with a very simple static function:
 > Closure::getCurrent().
 >

How about mutual recursion, where two of these functions call each 
other? Currently one can write

$left = function(array $a) use(&$second) { ... };
$second = function(array $a) use($first) { ... };

(The second can capture the first by value, but the first still needs to 
capture the second by reference.)

With Closure::getCurrent(), how does either function reference the other?