And indeed, you can do that in Perl too: 
multi compress () { () }
multi compress ($a) { item $a }
multi compress ($x, $y, *@xs) { $x xx ($x !=== $y), compress($y, |@xs)
+ }

my @x = <a a a a b c c a a d e e e e>;
say perl compress |@x;

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In reply to Re^7: 99 Problems in Perl6 by TimToady
in thread 99 Problems in Perl6 by Ovid

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