So, I've been playing around with what I call the trivial monad:
module TrivialMonad where
data TrivialMonad a = M a
recover :: TrivialMonad a -> a
recover (M x) = x
instance Monad TrivialMonad where
(M x) >>= f = f x
(M x) >> f = f
return x = M x
fail s = undefined
This is actually a surprisingly usefull little sucker- it allows you to
"demonadify" code. Which is usefull when you have some places where you
want to use the code within a monad, and some places where you don't. You
write the base bit of code monadically, and then demonadify it as needed.
The first question I have is it is possible to implement this guy without
wrapping the value in a constructor? What I'd like to do is replace the:
data TrivialMonad a = M a
with something like:
type TrivialMonad a = a
and then be able to junk the recover function.
The second question I have is: is there any hope of getting something like
this into the standard library?
Thanks,
Brian
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