@hexadrop/either

Either monad implementation

``bash
npm install --save @hexadrop/either
`

Using bun

`bash
bun add @hexadrop/either
`

What it does

It provides an implementation of the Either monad in TypeScript. The Either monad is a popular
functional programming concept used to handle computations that can result in two possible outcomes:
a successful result (Right) or an error (Left). This is useful for handling computations that can fail,
providing a way to chain operations while keeping error handling separate.

How to use

The @hexadrop/either package default exports a class Either with methods to create an instance
representing a left or right value (Either.left and Either.right),
check the type of the value (isLeft and isRight),
retrieve the value (getLeft, getRight, getLeftOrElse, getRightOrElse),
and transform the value (mapLeft, mapRight, flatMapLeft, flatMapRight).

$3

`typescript
import Either from '@hexadrop/either';

// Create a Right value
const right = Either.right('This is a right value');
console.log(right.isRight()); // true
console.log(right.getRight()); // 'This is a right value'

// Create a Left value
const left = Either.left('This is a left value');
console.log(left.isLeft()); // true
console.log(left.getLeft()); // 'This is a left value'
`

$3

`typescript
// Use mapRight to transform a Right value
const transformedRight = right.mapRight(value => value.toUpperCase());
console.log(transformedRight.getRight()); // 'THIS IS A RIGHT VALUE'

// Use mapLeft to transform a Left value
const transformedLeft = left.mapLeft(value => value.toUpperCase());
console.log(transformedLeft.getLeft()); // 'THIS IS A LEFT VALUE'
`

$3

`typescript
// Use flatMapRight to transform a Right value into a new Either
const flatMappedRight = right.flatMapRight(value => Either.right(value.length));
console.log(flatMappedRight.getRight()); // 20

// Use flatMapLeft to transform a Left value into a new Either
const flatMappedLeft = left.flatMapLeft(value => Either.left(value.length));
console.log(flatMappedLeft.getLeft()); // 19
``

Hexadrop Code Quality Standards

Publishing this package we are committing ourselves to the following code quality standards:

- Respect Semantic Versioning: No breaking changes in patch or minor versions
- No surprises in transitive dependencies: Use the bare minimum dependencies needed to meet the purpose
- One specific purpose to meet without having to carry a bunch of unnecessary other utilities
- Tests as documentation and usage examples
- Well documented README showing how to install and use
- License favoring Open Source and collaboration