Re: callback for regex engine

[zork42]

I was wondering if there is a capability in Perl to register a call back to the regex engine and call that registered function each time a particular match is made.

This might be of interest:
s///e and s///ee allow you to execute arbitrary any code (presumably including function calls) for each match
See s/PATTERN/REPLACEMENT/msixpodualgcer in Regexp Quote Like Operators (you have to go down a few pages):

e  Evaluate the right side as an expression.
ee Evaluate the right side as a string then eval the result.

UPDATE: s/arbitrary/any/
(In response to ikegami's post below. Unless I'm misunderstanding ikegami's misunderstanding :) )