Select Code to Download

use strict;
use warnings;
...
runloop unable to compile 'use strict; $X =~ /^N(?!.*00$).*$/': Global
+ symbol "$X" requires explicit package name at (eval 2) line 1.

code: sub { for (1 .. 1) { local $_; package main; use strict; $X =~ /
+^N(?!.*00$).*$/;} }

use strict;
use warnings;
...
           '?<!Y' => sub { scalar $Y =~ /^N.*(?<!00$)$/  },
           }
        );

X = Nxxxxxx000
Y = Nxxxxxx001
...
?!Y  535499/s  63%   -- -29% -34%
?!X  750772/s 129%  40%   --  -7%
?<!Y 805492/s 146%  50%   7%   --