exceptional

Essentially the Maybe type with error messages.

https://github.com/

LTS Haskell 14.27:0.3.0.0
Stackage Nightly 2019-09-21:0.3.0.0
Latest on Hackage:0.3.0.0

See all snapshots exceptional appears in

BSD-2-Clause licensed by Peter Harpending
Maintained by [email protected]
This version can be pinned in stack with:exceptional-0.3.0.0@sha256:8d310cde1b8562f7a31c42951c42b5de154fe433a5dbfc6e14b0e7eae7094b82,3066

Module documentation for 0.3.0.0

Depends on 2 packages(full list with versions):
base, exceptions

exceptional

This is a Haskell library that exists to house a type:

data Exceptional x
  = Failure String
  | Success x

It’s much like Maybe, except instead of Nothing, we have Failure String.

A comparison could also be made to Either String. I made this library because I was dissatisfied with the Monad instance for Either. In this type, fail = Failure. It’s rather simple.

Installing

cabal install exceptional

Or, add exceptional to the build-depends field in your .cabal file.