Backreferences Make Reversing Regexes Fun for the Whole Family, a few nodes up in this thread, gives a good explanation of the difficulties in reversing regexen. Once I understood where the difficulties were, I realized I would not be able to make a module, so there isn't one.

Even so, it's possible to reverse a limited subset of regexen, so it still might be a workable approach for your situation.

Caution: Contents may have been coded under pressure.

In reply to Re^2: Regex::Reverse tricky test cases by Roy Johnson
in thread Regex::Reverse tricky test cases by Roy Johnson

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