Don't allow **, ++, *+, ???, {n}*, {n}+, and other combinations of double repetition
Make {n,m} closer to PCRE, and parse {} as chars
(a+)+, (a*)*, etc are allowed. Disallowing the contiguous double reps make the NFA graph easier to work with, that's the only reason for this change really.
Changes:
**,++,*+,???,{n}*,{n}+, and other combinations of double repetition{n,m}closer to PCRE, and parse{}as chars(a+)+,(a*)*, etc are allowed. Disallowing the contiguous double reps make the NFA graph easier to work with, that's the only reason for this change really.