Re: [Haskell-cafe] What to call Occult Effects

On Wed, Nov 11, 2020 at 09:47:43PM -0500, David Feuer wrote:

If m is occlusive, so is ReaderT e m:

[...]

I believe this works for StateT as well.

I am puzzled what you mean by that, given that State s a = StateT s Identity a and while "Identity" is "occlusive", State is not. λ> import Control.Monad λ> import Control.Monad.Trans.State.Strict λ> runState (liftM2 (const id) (put True :: State Bool ()) get) False (True,True) λ> runState ((const id) (put True :: State Bool ()) get) False (False,False) -- Viktor.