gustavovalle23 / either-pattern

Either Pattern TypeScript Project

Overview

This TypeScript project demonstrates the usage of the Either pattern, a functional programming concept, to handle success and error scenarios in a more expressive and composable way. The Either type can represent either a success value (Right) or an error value (Left), providing a clean and structured way to handle different outcomes.

Table of Contents

• Installation
• Usage
• Examples
• Contributing
• License

Installation

Ensure you have Node.js installed on your machine.

1. Clone the repository:

   git clone https://github.com/gustavovalle23/either-pattern

2. Navigate to the project directory:

   cd either-pattern

3. Install dependencies:

   yarn install

Usage

To use the Either pattern in your TypeScript project, import the Either class from the either.ts file. The Either class takes two type parameters: the success type and the error type.

import { Either } from './either';

// Example usage
const result: Either<string, number> = Either.right(42);

result.match({
  left: (error) => console.error(`Error: ${error}`),
  right: (value) => console.log(`Success: ${value}`),
});

Examples

Handling Success

import { Either } from './either';

const successResult: Either<string, number> = Either.right(42);

successResult.match({
  left: (error) => console.error(`Error: ${error}`),
  right: (value) => console.log(`Success: ${value}`),
});

Handling Error

import { Either } from './either';

const errorResult: Either<string, number> = Either.left('An error occurred');

errorResult.match({
  left: (error) => console.error(`Error: ${error}`),
  right: (value) => console.log(`Success: ${value}`),
});

Chaining Operations

import { Either } from './either';

function divide(x: number, y: number): Either<string, number> {
  if (y === 0) {
    return Either.left('Division by zero');
  }
  return Either.right(x / y);
}

const result = divide(10, 2)
  .flatMap((value) => divide(value, 5))
  .match({
    left: (error) => console.error(`Error: ${error}`),
    right: (value) => console.log(`Success: ${value}`),
  });

License

This project is licensed under the MIT License - see the LICENSE file for details.