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

Module documentation for

Depends on 2 packages(full list with versions):


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.


cabal install exceptional

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