Result

In functional programming, a Result Monad is a type that represents the result of a computation that can potentially fail or produce an error. It provides a way to handle errors or exceptional cases in a functional and composable manner.

The Result Monad typically has two possible values:

• Success: Represents a successful computation or operation. It contains the result or value produced by the computation.

• Failure: Represents a failed computation or operation. It contains information about the error or exceptional condition that occurred.

The key idea behind the Result Monad is to encapsulate the success or failure of a computation within the monadic type. By using this monadic structure, you can chain operations together and propagate the error state without explicit error handling in each step.

A simple Typescript utility library for functional programming with result monad.

Installation

You can install Library Name via NPM:

npm install @nehemy/result

Usage

To use Result, simply add a reference to the package in your typescript project and include the appropriate import:

import { Result } from "@nehemy/result";

Then, you can use the result class as follow and its methods:

let result = new Result<number>(12);
let failureResult = new Result<number>(new Error()); 

console.log(result.hasValue); // true
console.log(result.isSuccessful); // true
console.log(result.isNotSuccessful); // false
console.log(result.value); // 12

console.log(failureResult.hasValue); // false
console.log(failureResult.isSuccessful); // false
console.log(failureResult.isNotSuccessful); // true
// it is important to check if result is successful before getting result's value
console.log(failureResult.value); // throws error


result = new Result<number>(12);
failureResult = new Result<number>(new Error());

result.or(4);
console.log(result.value); // 12

failureResult.or(4);
console.log(failureResult.value); // 4

result.orInvoke(() => 4); // 12
failureResult.orInvoke(() => 4); //4 


result.match(
  value => console.log(value),
  error => console.log("Error")
); // 12

failureResult.match(
  value => console.log(value),
  error => console.log("Error")
); // "Error"

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for more information.

License

Library Name is licensed under the MIT License. See LICENSE for more information.