in reply to Re: Matching string containing values between 0 and 100 inclusive
in thread Matching string containing values between 0 and 100 inclusive

That compiles a regexp pattern every run.

/^(\d+)(??{$^N >=0 && $^N <= 100 ? "" : "(?!)"})$/

should be

/^(\d+)(?(?{ $^N < 0 || $^N > 100 })(?!))$/

And match failures would be cheaper still as

/^(\d+)$(?(?{ $^N < 0 || $^N > 100 })(?!))/