result-type-simple

A simple Result object type implementation that I like and want to use in several projects.

type Result a = Error String | OK a

The Result constructor takes an err and an ok parameter.

• err - when provided the Result object is considered to be errored out.
• ok - this will be the assigned value of the Result object.

isOK : Result a -> Bool

Given a Result object determine if it is not an error.

map : (a -> b) -> Result a -> Result b

Given a function that transforms the Result value from a -> b, that function will be applied if Result.isOK is true. Otherwise the original result will be returned.

either (a -> b) -> (a -> b) -> Result a -> Result b

Given 2 functions, the first function will be called when Result.isOK is false and the second when Result.isOK is true. Both functions will receive the Result object's value.

chain (Result a -> Result b) -> Result a -> Result b

Given a function that returns a result map the unwrapped result value to the input of that function. The given function is responsible for returning a Result object. This can effectively be used as an unwrap function.

curry (a -> a) -> Result (really, it's just a guess at best)

Enables you to curry the map and either functions with the curry library of your choice.

Example (es6):

import { curry } from 'ramda';
import { curry as ResultCurry } from 'result-type-simple';

const Result = ResultCurry(curry);

Example (es5):

var curry = require('ramda').curry
var Result = require('result-type-simple').curry(curry);