| Portability | portable |
|---|---|
| Stability | experimental |
| Maintainer | Ralf Laemmel, Joost Visser |
| Safe Haskell | None |
Control.Monad.Maybe
Description
This module introduces the MaybeT monad transformer. It is basically a simplification of the ErrorT monad transformer.
Documentation
The monad transformer MaybeT.
Instances
| MonadTrans MaybeT | |
| MonadUnTrans MaybeAlg MaybeT | Unlifting the partiality monad transformer. |
| MonadReader r m => MonadReader r (MaybeT m) | |
| MonadState s m => MonadState s (MaybeT m) | |
| MonadWriter w m => MonadWriter w (MaybeT m) | |
| Monad m => Monad (MaybeT m) | |
| Monad m => Functor (MaybeT m) | |
| MonadFix m => MonadFix (MaybeT m) | |
| Monad m => MonadPlus (MaybeT m) | |
| MonadIO m => MonadIO (MaybeT m) | |
| MonadCont m => MonadCont (MaybeT m) |