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: [email protected]
url: http://www.cs.kuleuven.be/~toms/
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