davidboers / elmeither

Implements the Either declaration in Elm.

Either Elm

The first time I tried Functional Programming, I thought "What the hell is this? Why would anybody program this way?" Then, I tried it out a little more. Then I realized how fun it is. Particularly the genius that comes with having to be resourceful. In no instance is that clearer than Haskell's Maybe and Either declarations.

-- Basically a nullable value. It could exist (as any type) or it could be Nothing. 
-- Akin to Java's '@nullable' annotation

type Maybe a
    = Just a
    | Nothing

-- Could be of type a or type b.

type Either a b
    = Left a
    | Right b

Although Maybe is implemented in Elm, Either is not; until now. This module contains a declaration of Haskell's Either type, verbatim from the source code of the GHC library. It also contains a couple of other functions related to the declaration.

Just do

elm install kingwither/elmeither

and the package will be installed!

import Either exposing (Either(..))

You're all set! Either is now Either Haskell Elm!

elmeither's Issues

Mistake in readme

Hello, I believe this line in the readme

Although Maybe is implemented in Elm, Either is not; until now.

is untrue. This Either package exists as well https://package.elm-lang.org/packages/toastal/either/latest/