[Haskell-cafe] An interesting monad: "Prompt"

Thomas Hartman tphyahoo at gmail.com
Sat Nov 24 13:06:17 EST 2007


that did it, thanks.

2007/11/24, Brent Yorgey <byorgey at gmail.com>:
>
>
> >
> > > -- Just for fun, make it work with StateT as well
> > > -- (needs -fallow-undecidable-instances)
> >
> > > instance (Monad (t m), MonadTrans t, MonadPrompt p m) => MonadPrompt p
> (tm) where
> > >    prompt = lift . prompt
> >
>
> Looks like that should be MonadPrompt p (t m) rather than (tm).  Note the
> space.
>
> -Brent
>
>


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