Select Code to Download

Example:
...
  if ($_ % 2 > 0) { DROP();} # <----- is what I would LOVE
                             # to do
}

Grep:
@moo = grep {($_ % 2 > 0)?0:1;} @moo;
...
for (my $i=0;$i<@moo;$i++)
{ if ($moo[$i] % 2 > 0)  {splice @moo, $i, 1;} }
# wow is this slow