This probably runs faster than anything with map or grep, and isn't much longer than the fully golfed ones. 
sub compress {
 my @x;
 !@x || $_ ne $x[-1] and push @x, $_ for @{$_[0]};
 \@x
}

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In reply to Re: reduce like iterators by NERDVANA
in thread reduce like iterators by LanX

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