Hello,
is there a monad transformer to consume an input list? I've got external events "streaming into the monad" that are consumed on demand and I'm not sure if there's something better than a StateT.
I wondered that, too. I wondered whether there is something inverse to Writer, and Reader is appearently not the answer. Now I think, that State is indeed the way to go to consume a list. Even better is StateT List Maybe:
next :: StateT [a] Maybe a next = StateT Data.List.HT.viewL -- see utility-ht package
Or make the transformer a MonadPlus transformer and call mzero for the empty list? Tom -- Tom Schrijvers Department of Computer Science K.U. Leuven Celestijnenlaan 200A B-3001 Heverlee Belgium tel: +32 16 327544 e-mail: tom.schrijvers@cs.kuleuven.be url: http://www.cs.kuleuven.be/~toms/