Rustty NPM | npm.io

Rustty

Rustty is a library that brings various data structures and algorithms such as iconic Result and Option from the Rust standard library to the JavaScript world.

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Installation

npm install rustty

Usage

You can either import the whole library or just the Result and Option types.

import "rustty";

Will import only the Result and Option types. On the other hand, if you want to import the whole library, you can do by using the following statement:

import "rustty/full";

Note that using the full version will add a lot of methods to the prototypes of the built-in types such as Array.

Examples

Using Result and Option

import "rustty";

function divide(a: number, b: number): Result<number, string> {
  if (b === 0) {
    return Err("Division by zero");
  }

  return Ok(a / b);
}

const result = divide(10, 5); // Ok(2)

console.assert(result.isOk() === true); 
console.assert(result.unwrap() === 2);

const failed = divide(10, 0); // Err("Division by zero")

console.assert(failed.isErr() === true);
console.assert(failed.unwrapErr() === "Division by zero");

// Alternatively, you can use Option type to indicate that the result may be null or undefined

function divide(a: number, b: number): Option<number> {
  if (b === 0) {
    return None;
  }

  return Some(a / b);
}

const result = divide(10, 5).unwrap(); // 2
const failed = divide(10, 0).unwrap(); // Throws an error

Using additional methods

import "rustty/full";

const arr = [1, 2, 3, 4, 5];

// Swap elements at indices 0 and 4
arr.swap(0, 4);

arr.windows(2).forEach(window => {
  console.log(window); // [5, 2], [2, 3], [3, 4], [4, 1]
});

console.assert(arr.sum() === 15);
console.assert(arr.product() === 120);

arr.swap(0, 4);

arr
  .groupBy((a, b) => Math.round(a / 2) === Math.round(b / 2))
  .forEach(group => console.log(group)); // [1, 2], [3, 4], [5]

console.assert(arr.max() === 5);
console.assert(arr.min() === 1);