G'day all. Quoting Peter Simons <[EMAIL PROTECTED]>:
> Just curious: Why would you want something like that? I thought that > the good thing(tm) about regular expressions is that they can be > parsed by a finite state machine rather than a recursive descent > parser, [...] Regular expressions can be parsed by a finite state machine. POSIX regexes can't. Or, at least, not quite, particularly when you have substring extraction and substitution to take into account. At the very least, you need some kind of backtracking NFA. The story is even worse for Perl-compatible regexes. Nobody is entirely sure what classes of computation can be done with this language but, for example, it's possible to construct a Perl regex which only matches strings of prime length. > so for all I know, the C regular expression library that comes > with your system is most likely much faster than any Parsec code would > every be. Well, you never know until you try. There _is_ overhead in converting strings from Haskell to C and back again. Yes, Parsec is probably the wrong fit, but I think there might be merit in at least trying a full Haskell implementation. Cheers, Andrew Bromage _______________________________________________ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe