failure-0.1.0.1: A simple type class for success/failure computations.

Safe HaskellSafe-Inferred

Control.Failure

Contents

Description

Type classes for returning failures.

Synopsis

Type class

class Monad f => Failure e f where

Methods

failure :: e -> f v

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.

Instances

Convenience String failure

Convert Failures into concrete types

class Try f where

Associated Types

type Error f

Methods

try :: Failure (Error f) f' => f a -> f' a

Instances

Try [] 
Try Maybe 
Try (Either e)