catch package:incipit-core

catch :: forall e (r :: EffectRow) a . Member (Error e :: (Type -> Type) -> Type -> Type) r => Sem r a -> (e -> Sem r a) -> Sem r a

incipit-core IncipitCore

Recover from an error that might have been thrown in the higher-order action given by the first argument by passing the error to the handler given by the second argument.

catchJust :: forall e (r :: EffectRow) b a . Member (Error e :: (Type -> Type) -> Type -> Type) r => (e -> Maybe b) -> Sem r a -> (b -> Sem r a) -> Sem r a

incipit-core IncipitCore

The function catchJust is like catch, but it takes an extra argument which is an exception predicate, a function which selects which type of exceptions we're interested in.