> # use the regex to calculate the number of all possible strings (up to a given length?!)

you know it's perfectly possible to construct valid regexes which won't terminate before all suns have burned out...

So your empirical approach is only practicable by limiting the regexes to a reasonable subset.

One thinkable way could be limiting to pure state machines and exploring feasible transits between states.

But this is highly speculative without a detailed question from the OP, IMHO it's a case of XY!

Cheers Rolf

In reply to Re^2: Analysis of Regular Expressions by LanX
in thread Analysis of Regular Expressions by PetaMem

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