Re: Regular expression libraries

[Paul Eggert]

Andreas Schwab wrote:
> > Another library is in that list:
> >
> >   - The GNU C library, which ordinarily uses a DFA but which uses
> > backtracking if needed.
> But it doesn't support a gap.

True, but none of the others do either. Only the old glibc code (which survives 
only in Emacs now) does that, as far as I know.

I doubt whether it'd be that hard to add gap support to any regexp matcher, as 
it's simply interposing an address calculation.