
1 Jun
2021
1 Jun
'21
7:01 p.m.
This is to advertise the proposal (https://gitlab.haskell.org/ghc/ghc/-/issues/19922) to add a superclass to the MonadTrans type class in Control.Monad.Trans. A Monad transformer 'trans' lifts a 'Monad m' to a 'Monad (trans m)'. This proposal code-ifies that with a superclass constraint, an impliciation constraint enabled by the recent extension QuantifiedConstraints: class (forall m. Monad m => Monad (trans m)) => MonadTrans trans where .. This is the main motiviating example of the Quantified Class Constraints paper https://gkaracha.github.io/papers/quantcs.pdf