in reply to Non-capturing zero-width negative lookahead

x $foo =~ /( (:? . | \n (?! \n\n) )+ ) /x

You have a bug: (:? should be (?:. That's what ends up as your second capturing group.

print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

In Section Seekers of Perl Wisdom