I know, obfuscated != elegant. Nevertheless, I thought it was kind of neat. 
my $str = 'xx556xx';
my @x = grep --$|, $str =~ m/((.)\2*)/g;
print join ',', @x;

[download]
The trick with $| is that it's a toggle, so grep throws away every other member of its input. The same thing could be done with a normal variable like so: 
my $str = 'xx556xx';
my $tog = 0;
my @x = grep $tog = !$tog, $str =~ m/((.)\2*)/g;
print join ',', @x;

[download]
or using split: 
my $str = 'xx556xx';
my $tog = 0;
my @x = grep $tog = !$tog, split /(?<=(.))(?!\1)/, $str;
print join ',', @x;

[download]
Caution: Contents may have been coded under pressure.

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

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