If I'm understanding your question correctly (and I may well not be), you may want to take a look at Regexp::Assemble, which is roughly similar to your #2, but it will produce a more efficient regex (e.g., (re[1234]) instead of (re1|re2|re3|re4)) and has an option for identifying which of the original source regexes was matched.

I've used Regexp::Assemble to good effect in relatively simple cases to locate all words present in a body of text from a list of a couple hundred target words, but have not had cause to use the 'report source regex' feature, so I can't comment on how well that works.

In reply to Re: Regular Expression (Regex) Sieve by dsheroh
in thread Regular Expression (Regex) Sieve by Wiggins

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