http://www.perlmonks.org?node_id=1018343


in reply to Real life uses for closures.

Here's some examples from my modules:

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Re^2: Real life uses for closures.
by DrHyde (Prior) on Feb 13, 2013 at 12:00 UTC

    Oh, and if you want something really closurey, Sort::MultipleFields. There's no clean way of doing what that does without using closures.

    The other obvious approach to that problem is to build some code using eval. In fact, I find that you can almost always replace eval with a closure.

[reply]
[d/l]

      Technically none of the examples from Sort::MultipleFields employ closures; they just use anonymous functions. Closures "close over" a variable.

      package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name
[reply]

        Here's a closure from it ... 

        $sortsub = sub($$) {
  $spec->($_[0]->{$field}, $_[1]->{$field}) ||
  $oldsortsub->($_[0], $_[1])
}

        [download]

        Lemme guess - did you just grep the code for /sub {/? :-)

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[d/l]
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