I want a code generator that, even though run from perl 5.14+, can generate code that runs on perl 5.12 and lower.

Unless I'm missing a CPAN module capable of stringifying regexes, I'm afraid you won't get that from Perl itself: I believe the relevant commit is fb85c0447bf1, it looks like the stringification behavior is not configurable. The change was discussed, including compatibility, on P5P, e.g. here.

If you really don't like the two suggestions from perl5140delta, then you might actually want to consider using an older Perl to generate your regex strings.

In reply to Re^5: Dumping regexp for Perl versions earlier than 5.14 by Anonymous Monk
in thread Dumping regexp for Perl versions earlier than 5.14 by perlancar

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