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Re: SRFI-115 issues
Alex Shinn scripsit:
> I actually need to separate the features better because things like
> "non-greedy" repetitions can actually be supported by non-backtracking
> implementations, "if" is just a shortcut for "or" with a look-ahead,
> and I have to think about whether it's possible for atomic/commit to
> be supported without backtracking.
> Ultimately with a little effort everything can be supported. One
> trick to support backreferences in DFA impls is to replace them with
> .* and use post-processing to verify. So it's more a matter of what's
> readily available, not what's possible.
In that case I think there should be a unified system and the feature
mechanism should be abandoned.
Editorially, you shouldn't say that backreferences are prohibitively
expensive: if you need them, you need them. Just drop "prohibitively".
You escaped them by the will-death John Cowan
and the Way of the Black Wheel. cowan@xxxxxxxx
I could not. --Great-Souled Sam http://www.ccil.org/~cowan