Re: [Haskell-beginners] MonadThrow, MonadReader and shake

Hello,

Hello sylvain.

The` toRuchePath` function has the following constraints on `m`: `MonadReader Beamline m, MonadThrow m`

In your code, `m ~ Action` (from Shake) which doesn't fulfil the constraints (hence the error).

[...]

If you want `m ~ ReaderT Beamline m IO`, you can use something like: `liftIO $ runReaderT stateBeforeCallingShake $ toRuchePath attachements` (you need `stateBeforeCallingShake <- ask` before calling shake).

ok, I will check this :). Does it mean that if an instance of the MonadReader was writtent for shake (Action). it should work out of the box ? Fred