Introduction

rustly is a TypeScript library that brings the power of Rust's Option and Result types to the TypeScript ecosystem. This package provides robust error handling and nullable value representation, allowing you to write more reliable and expressive code. The Option type deals with nullable values, while the Result type handles potential errors.

Features

• Rust-like Option and Result types for TypeScript
• Safe and expressive error handling
• Familiar Rust-inspired API
• Easily manage nullable values and errors in a type-safe manner

Installation

You can install rustly using npm:

npm install --save rustly

Usage

Result Usage

import { Ok, Err, Result } from 'rustly';

const success = Ok(1);
const failure = Err('not a number');

success.ok(); // Option(1)
success.isOk(); // true
success.isOkAnd(val => val === 1); // true

success.err(); // None
success.isErr(); // false
success.isErrAnd(val => val === 1); // false

success.unwrap(); // 1
success.unwrapOr('not a number'); // 1
success.unwrapErr(); // throws
success.unwrapErrOr(42); // 42

success.expect('not a number'); // 1
success.expectErr('not a number'); // throws

const successPlusOneOrZeroIfErr = success.match({
  ok(val) {
    // If it is Ok return the value + 1
    return val + 1;
  },
  err() {
    // Return 0 if there was an error
    return 0;
  }
})

success.map(val => val + 1); // Ok(2)
success.mapErr(val => val + 1); // Ok(1)

success.and(Ok(2)); // Ok(2)
success.and(Err('not a number')); // Err('not a number')

// Merge array of Result into a single Result
const arrayOfResult = [Ok(1), Ok(2), Ok(3)], Err('not a number')];
Result.merge(arrayOfResult); // Ok([1, 2, 3])
Result.mergeErr(arrayOfResult); // Err(['not a number'])

// Nested Result
const nestedResult = Ok(Ok(1));
nestedResult.flatten(); // Ok(1)
success.map(val => Err()).flatten(); // Err()

Option usage

import { Some, None, Option } from 'rustly';

const some = Some(1);
const none = None();

some.isSome(); // true
some.isSomeAnd(val => val === 1); // true

some.isNone(); // false
some.isNoneAnd(val => val === 1); // false

some.unwrap(); // 1
some.unwrapOr('not a number'); // 1

some.expect('not a number'); // 1

const somePlusOneOrZeroIfNone = some.match({
  some(val) {
    // If it is Some return the value + 1
    return val + 1;
  },
  none() {
    // Return 0 if it is None
    return 0;
  }
})

none.insert(5); // Some(5)
const taken = some.take(); // Some(1) and some is now None
some.replace(2); // Some(2)

some.map(val => val + 1); // Some(2)
some.mapOr(42, val => val + 1); // Some(2)
none.mapOr(42, val => val + 1); // 42

some.okOr('not a number'); // Ok(1)
none.okOr('not a number'); // Err('not a number')

some.or(Some(2)); // Some(1)
none.or(Some(2)); // Some(2)

some.and(Some(2)); // Some(2)
none.and(Some(2)); // None

Promise override

Promise.resolveFromOk(1)
  .thenOnOk(okvalue => console.log(okvalue))
  .thenOnErr(errvalue => console.log(errvalue));

Promise.resolveFromErr(1)
  .thenOnOk(okvalue => console.log(okvalue))
  .thenOnErr(errvalue => console.log(errvalue)); 

Contributing

Contributions are welcome! If you find any issues or have new features to add, please feel free to open an issue or submit a pull request.

License

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