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FWIW this "works" somehow, but lacks the elegance of the "while solution" approach...

Please note that now, one can have more than just one loop var, like a "pointy block" in Perl6.

The cheat is that $a has to be global here to work under strict.*

Using my $a wouldn't work, because the scope only starts after the statements semicolon, and the body-sub is defined before.

use strict; use warnings; use Data::Dump qw/pp dd/; sub iter (&$;@) { my $gen = shift; my $body = pop; for (my $it = $gen->(@_) ; $it->(@_); ) { $body->(); } } for my $limit (reverse 1..5) { iter { countdown($limit) } $a => sub { print "$a: "; }; print "\n"; } sub countdown{ my $val = shift; my $it = sub { if ($val--) { $_[0]=$val; return 1; } return; # stop iteration }; return $it; }
4: 3: 2: 1: 0: 3: 2: 1: 0: 2: 1: 0: 1: 0: 0:

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Wikisyntax for the Monastery


Renamed loop to iter ... the loop construct in Perl6 is another beast, and wanted to avoid confusion.

*) remember $a and $b are global to allow sort to work.

In reply to Re: Can I check if a loop's scope is entered for the first time? (functional approach) by LanX
in thread Can I check if a loop's scope is entered for the first time? by LanX

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