Clem Wang - 2012-02-09

[:] also triggers an error, when many other regexp packages don't.

IMHO, if there's just the one colon at the beginning (or end) of the [] expression, then I think Quex should just treat the colon as just character. However, if there are two colons, then I would make that an error, unless it's a known pattern:

[:pattername:]

where patternname is something like whitespace.

Not a big deal. I can see it being annoying if one is porting over a bunch of regular expressions and they have to be tweaked to account for these minor differences.