Re^2: Using regex to match double letters, and only double letters

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

for my $s (qw( xxabyycdzz axxbmmmcyyd xxyy exxyy xxyyf xxgyy mmm mmmen
+nn )) {
    say for '---', $s;
    say $2 while $s =~ /(?|^((.))\2(?!\2)
                          |(?<=(.)(?!\1))(.)\2(?!\2))/gx;
}
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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
[download]

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Re^3: Using regex to match double letters, and only double letters by Locutus (Beadle) on Apr 16, 2018 at 15:46 UTC
Your regex (as a whole) matches the "something else before" character as well - printing the content of a certain capture group is cheating! ;-)	[reply]