sub shrink { my $dbit = 0; for (my $sbit = 0; $sbit < length($_[0]) * 8; $sbit++) { next if $sbit % 8 == 7; vec($_[0], $dbit++, 1) = vec($_[0], $sbit, 1); } my $dlen = length($_[0]) * 7 / 8; $dlen++ unless $dlen == int($dlen); $dlen = int($dlen); my $extra = length($_[0]) - $dlen; if ($extra > 0) { substr($_[0], $dlen, $extra, ''); } for (my $pbit = $dbit; $pbit < $dlen * 8; $pbit++) { vec($_[0], $pbit, 1) = 0; } } sub grow { my $sbit = int(length($_[0]) * 8 / 7) * 7 - 1; for (my $dbit = int(length($_[0]) * 8 / 7) * 8 - 1; $dbit >= 0; $dbit--) { vec($_[0], $dbit, 1) = $dbit % 8 == 7 ? 0 : vec($_[0], $sbit--, 1); } }