Hoopl: Combining CheckingFuelMonad with State?
Justin Bailey
jgbailey at gmail.com
Sat Jun 25 00:50:04 CEST 2011
I'd like to carry around some state when rewriting. It seems like
CheckingFuelMonad, etc. are set up to use with other monads but I
can't get the types to agree.
Using MTL I've managed to come up with these types:
> newtype RewriteOnce a = R (State Bool a)
> deriving (Monad)
>
> instance MonadState s (CheckingFuelMonad RewriteOnce) where
> get = undefined
> put = undefined
But I cannot write the definitions for get and put. Is this possible
or am I misundersanding CheckingFuelMonad? Is there a better approach
altogether?
Thanks in advance for any help!
Justin
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