Maybe it shoudl be possible to disable the trie optimisation for thos cases of alternation where it doesn't benefit.
Maybe you can disable trie optimizations by setting ${^RE_TRIE_MAXBUF} = 0?
Perl 6 - links to (nearly) everything that is Perl 6.

In reply to Re^2: Unefficient Regexp 'Matching this or that' by moritz
in thread Unefficient Regexp 'Matching this or that' by pelagic

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