Recursive regexps?

[Magnus Lie Hetland]

It seems there are a *couple* of (experimental) PCRE features that
allow recursive matching:

  [T]here is some experimental support for recursive patterns using
  the non-Perl items (?R), (?number) and (?P>name). Also, the PCRE
  "callout" feature allows an external function to be called during
  pattern matching.

  [http://www.slabihoud.de/spampal/pcrecompat.html]

All of these seem pretty useful/neat :-}

-- 
Magnus Lie Hetland       Fallen flower I see / Returning to its branch
http://hetland.org       Ah! a butterfly.           [Arakida Moritake]