Currently, yes; I was experimenting with type families. But it's pretty
simple to get it to compile on 6.6.1:
- remove the {-# LANGUAGE #-} pragma and replace with {-# OPTIONS_GHC
-fglasgow-exts -fallow-undecidable-instances #-}
- change the class declaration for MonadPrompter from
> class Monad m => MonadPrompter m where
> type PromptType m :: * -> *
> prompt :: PromptType m a -> m a
to
> class Monad m => MonadPrompter p m | m -> p where
> prompt :: p a -> m a
- change all the instance declarations from something like this:
> instance MonadPrompter (XXX) where
> type PromptType (XXX) = YYY
> prompt = ...
to something like this:
> instance MonadPrompter YYY (XXX) where
> prompt = ...
& you're done.
-- ryan
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