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Re^2: Complex regex question

by rsFalse (Hermit)
on Sep 25, 2019 at 18:52 UTC ( #11106695=note: print w/replies, xml ) Need Help??


in reply to Re: Complex regex question
in thread Complex regex question

One more variant:
#!/usr/bin/perl # https://perlmonks.org/?node_id=11106665 use strict; use warnings; use Data::Dumper; $Data::Dumper::Indent = 0; my $string_three = "a aa 21a a 123 a b9 b bb aa1 1aa aa11 11aa [b42] ( +12a)"; my @captures = $string_three =~ m{ \b ([ab])? (\d+) ([ab])? \b (?(?{ 1 != grep defined, $1, $3 }) (*FAIL) ) }xmsg; print "RESULTS: ", ( Dumper \@captures ), "\n";
RESULTS: $VAR1 = [undef,'21','a','b','9',undef,'b','42',undef,undef,'1 +2','a'];
It generates triplets with one undefined value ($1 or $3), but you can grep defined values as AnomalousMonk mensioned.

EDIT:
Sorry for mistake. I changed condition "2 == grep defined, $1, $3" to "1 != grep defined, $1, $3", because one of $1 or $3 must be defined.


ADDED:
my @captures = $string_three =~ m{ \b ([ab])? (\d+) (?(1) | ([ab]) ) \b }xmsg;
Similar approach using conditional. It captures in same way.

ADDED-2:
Also:
my @captures = $string_three =~ m{ \b ([ab])? (\d+) (?(1) (*ACCEPT) ) ([ab]) \b }xmsg;

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