failure-0.1.0.1: A simple type class for success/failure computations.ContentsIndex
Control.Failure
Contents
Type class
Wrapping failures
Convenience String failure
Convert Failures into concrete types
Description
Type classes for returning failures.
Synopsis
class Monad f => Failure e f where
failure :: e -> f v
class Failure e f => WrapFailure e f where
wrapFailure :: (forall eIn. Exception eIn => eIn -> e) -> f a -> f a
newtype StringException = StringException String
failureString :: Failure StringException m => String -> m a
class Try f where
type Error f
try :: Failure (Error f) f' => f a -> f' a
data NothingException = NothingException
data NullException = NullException
Type class
class Monad f => Failure e f where
Methods
failure :: e -> f v
show/hide Instances
Wrapping failures
class Failure e f => WrapFailure e f where
Methods
wrapFailure :: (forall eIn. Exception eIn => eIn -> e) -> f a -> f a
Wrap the failure value, if any, with the given function. This is useful in particular when you want all the exceptions returned from a certain library to be of a certain type, even if they were generated by a different library.
show/hide Instances
Convenience String failure
newtype StringException
Constructors
StringException String
show/hide Instances
failureString :: Failure StringException m => String -> m a
Call failure with a String.
Convert Failures into concrete types
class Try f where
Associated Types
type Error f
Methods
try :: Failure (Error f) f' => f a -> f' a
show/hide Instances
data NothingException
Constructors
NothingException
show/hide Instances
data NullException
Constructors
NullException
show/hide Instances
Produced by Haddock version 2.7.2