This is almost a repeat of tye's answer, but without peking at the others I came up with 
use strict;
use warnings;
use Data::Dumper;

my @repeats;
while ( 'xx556xx' =~ m/((.)(\2)*)/g ) {
    push @repeats, $1;
}
print Dumper(\@repeats);

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In reply to Re: Elegant way to split into sequences of identical chars? by tphyahoo
in thread Elegant way to split into sequences of identical chars? by pKai

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