Is there any way of avoiding the external module and catch an arbitrary number of nested parentheses with a "normal" Regex? I know that the Owl book says it can't be done, but I would like to put my mind at rest on this issue.
It depends on what you call a "normal" regex. If normal means without any perl specific things, it can not be done. But if you don't mind a perl specific regex, perlre has the solution:
The following pattern matches a parenthesized
group:
$re = qr{
\(
(?:
(?> [^()]+ ) # Non-parens without backtracking
|
(??{ $re }) # Group with matching parens
)*
\)
}x;
2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
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