Safe Haskell | Safe |
---|---|
Language | Haskell2010 |
Lifting the catch
operation.
- class MonadTrans t => LiftCatch t where
- type Catch e m a = m a -> (e -> m a) -> m a
- defaultLiftCatch :: (Monad m, LiftCatch n) => (forall x. n m x -> t m x) -> (forall o x. t o x -> n o x) -> Catch e m (StT n a) -> Catch e (t m) a
- module Control.Monad.Trans.Class
Documentation
class MonadTrans t => LiftCatch t where Source
The class of monad transformers capable of lifting catch
.
LiftCatch MaybeT Source | |
LiftCatch ListT Source | |
LiftCatch IdentityT Source | |
Monoid w => LiftCatch (WriterT w) Source | |
Monoid w => LiftCatch (WriterT w) Source | |
LiftCatch (ExceptT e) Source | |
LiftCatch (StateT s) Source | |
LiftCatch (StateT s) Source | |
LiftCatch (ReaderT r) Source | |
Monoid w => LiftCatch (RWST r w s) Source | |
Monoid w => LiftCatch (RWST r w s) Source |
type Catch e m a = m a -> (e -> m a) -> m a
Signature of the catchE
operation,
introduced in Control.Monad.Trans.Except.
:: (Monad m, LiftCatch n) | |
=> (forall x. n m x -> t m x) | Monad constructor |
-> (forall o x. t o x -> n o x) | Monad deconstructor |
-> Catch e m (StT n a) | |
-> Catch e (t m) a |
Default definition for the liftCatch
method.
module Control.Monad.Trans.Class