Rulex – A new, portable, regular expression language

Re:Rulex – A new, portable, regular expression language by nsajko on Friday June 10, 2022 @07:17AM (#31692495)

Of course, Unicode is just another alphabet. Specific expressions might be problematic though, depending on the implementation.

EDIT: If malicious inputs are something to be worried about, I think a good way to do this would be to check for exceedingly costly blowups of various kinds during/after translation to a finite automaton (so before automaton execution). This would enable having complemented expressions when safe (in lots of cases, at least).

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Re:Rulex – A new, portable, regular expression language by joppy on Friday June 10, 2022 @08:01AM (#31692837)

To get something useful and not attackable, the complement operation would need to take the complement inside the set of valid UTF-8 strings rather than the set of all byte-sequences, which is probably doable but I'm not sure how straightforward it would be.

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Re:Rulex – A new, portable, regular expression language by nsajko on Friday June 10, 2022 @08:25AM (#31693062)

> the complement operation would need to take the complement inside the set of valid UTF-8 strings rather than the set of all byte-sequences

Anything else would be a bug in any case.

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