in reply to Subroutine Reference in a Regexp?

That'd be (??{ code }) - live demo of the following (requires a modern browser; don't mind the "Subroutine redefined" warnings, I'll have to get around to fixing those):

use warnings;
use strict;

my $string = "more than one part\nanother sentence more than";

sub getone { qr/more/ }
sub gettwo { qr/than/ }

while ( $string =~ m{( (??{getone}) \s+ (??{gettwo}) )}xg ) {
    print "<$1>\n";
}

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Re^2: Subroutine Reference in a Regexp?
by Eily (Monsignor) on Nov 09, 2018 at 16:59 UTC

    I don't know how to check that but doesn't that stringify then recompile the precompiled regexes?

[reply]
      I don't know how to check that but doesn't that stringify then recompile the precompiled regexes?

      Hm, that's a good question, I'm not sure at the moment how to check either... hopefully inspiration will strike later :-)

      Your and jwkrahn's posts did remind me of a possibly important caveat: (??{...}) will re-execute the block of code every time, while interpolation will only execute it once:

      use warnings;
use strict;
#use re 'debug';

my $str = "foobar";

sub getit {
    print "Getit! pos=",pos($str)//"undef","\n";
    return qr/[aeiou]/i;
}

print "### haukex\n";
print "Matches: <", $str=~/(??{getit})/g, ">\n";

print "### jwkrahn\n";
my $reg_str = getit();
print "Matches: <", $str=~/$reg_str/g,    ">\n";

print "### Eily\n";
print "Matches: <", $str=~/@{[getit]}/g,  ">\n";

__END__

### haukex
Getit! pos=0
Getit! pos=1
Getit! pos=2
Getit! pos=3
Getit! pos=4
Getit! pos=5
Getit! pos=6
Matches: <ooa>
### jwkrahn
Getit! pos=undef
Matches: <ooa>
### Eily
Getit! pos=undef
Matches: <ooa>

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Re^2: Subroutine Reference in a Regexp?
by Amblikai (Scribe) on Nov 08, 2018 at 20:39 UTC

    Perl never ceases to amaze me!

    Thank you!

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