On 11-06-03 06:00 AM, Yitzchak Gale wrote:
Mario Blažević wrote:
I don't know if this helps, but the incremental-parser library has exactly the combinator you're looking for.
Wow, that is a beautiful implementation of a general parser library. So much simpler than Parsec. Thanks for pointing it out.
Thanks. I guess I should get to work fixing its deficiencies then.
Why are you hiding those nice Monoid classes in the parser package? Shouldn't it be a separate package?
I considered it, and I'll do it if there's interest, but for the first release I decided to keep them close to where they're needed. There was less work that way. I'd hate to release a standalone package with only half the instance implementations.
Edward Kmett has also been adding some nice Monoid abstractions lately. I haven't been following all of it. I wonder how yours and his relate.
If you mean semigroups, they are related but only through Monoid. Semigroup is a superclass of Monoid, whereas CancellativeMonoid and FunctorialMonoid are its subclasses. CancellativeMonoid is lying between a Monoid and Group in power. It would make more sense to merge my classes into some group package, though I don't see any obvious candidate on Hackage right now.