haskell/mtl

📋 Changes

• Add `Accum` monad.
• Generalize `MonadAccum` instance for all `Monad m` underlying `AccumT`, not just `Identity`.
• Allow building monokinded `ContT` if the compiler is MicroHs.
• Fix an issue where `QuantifiedConstraints` in the definition of `liftCallCC` was was preventing building under certain conditions.
• Add `Control.Monad.Class.onError`.
• Add various instances for `Data.Functor.Product.Product`.

📋 Changes

• Add `modifyError` to `Control.Monad.Error.Class`, and re-export from
• Make the `MonadCont` instance for `ContT` more polykinded; now, `r` is allowed
• Add a generic `liftCallCC` for use with any `MonadTrans`.
• Return re-export of `ExceptT` and related functions to `Control.Monad.Except`.
• Add `label` function to `MonadCont`

📋 Changes

• Add `modifyError` to `Control.Monad.Error.Class`, and re-export from
• Make the `MonadCont` instance for `ContT` more polykinded; now, `r` is allowed
• Add a generic `liftCallCC` for use with any `MonadTrans`.
• Return re-export of `ExceptT` and related functions to `Control.Monad.Except`.
• Add `label` function to `MonadCont`