Re: Self-recognizing programs and regular expressions

This is as far as I got:

^(?=.{65}\\\\Q\\1\\\\E\\\)\z)(\Q^(?=.{65}\\\\Q\\1\\\\E\\\)\z)(\E)\\Q\1\\E\)

It is a true inequ of sorts. However, it uses \Q, which is a quoting
construct, not a regex construct. So it doesn't work as  $x =~ /$x/,
only as $x =~ eval("qr/$x/"):

chomp(my $x = <<'EOF');
^(?=.{65}\\\\Q\\1\\\\E\\\)\z)(\Q^(?=.{65}\\\\Q\\1\\\\E\\\)\z)(\E)\\Q\1\\E\)
EOF
print "OK" if $x =~ eval("qr/$x/");

Going all the way to  $x = qr/.../; "$x" =~ $x;  doesn't help either,
because in the stringyfied version \Q-quoting is replaced by normal
\-escaping.

- Karsten