On Mon, Dec 12, 2011 at 00:18, Gregory Crosswhite
It is only recently that I have been able to grok what some and many are even about (I think), and they seem to only make sense in cases where executing the Alternative action results in a portion of some input being consumed or not consumed. "some v" means "consume at least one v and return the list of items consumed or fail", and "many v" means "consume zero or more v and return the list of items consumed or the empty list of none are consume". It thus makes sense for there to be some subclass of Alternative called something like "Consumptive" that contains these methods.
"Parsive"? I think the only reason they're in there is that Applicative and Alternative "came about" via experimentation with parsing (Applicative started its pre-ghc life as a parser combinator library). -- brandon s allbery allbery.b@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms