' 1a2' =~
  m/(.(?{$char = substr($_,pos(),1);
         print "$char ";
         print $char =~ m|\d|
               ? "digit\n"
               : "not digit\n"; }))+/;

##</code><code>##

__SIG__
use B;
printf "You are here %08x\n", unpack "L!", unpack "P4", pack
  "L!", B::svref_2object(sub{})->OUTSIDE;