---
Title: True Myth 2.1.0 Released
Subtitle: A bunch of neat new utility functions on Maybe for arrays and tuples.
Date: 2018-09-02 16:25
Updated: 2018-09-02 16:52
Category: Tech
Tags: [TypeScript, functional programming, monads, libraries, software development, open source software, True Myth]
Summary: >
A bunch of neat new utility functions on Maybe for arrays and tuples.
---
I’ve just released True Myth 2.1.0 ([source](https://github.com/chriskrycho/true-myth/tree/v2.1.0), [docs](https://true-myth.js.org)), which includes a handful of new utility functions for use with the `Maybe` types and arrays or tuples. Note that to make use of these you’ll need to be on at least TypeScript 3.0: they take advantage of the some of the shiny new features in the type system!
**Edit:** and, five minutes later, versions 2.1.1 and 2.1.2 are out with bugfixes consisting of "I forgot to export two functions. Now they're exported." Because that's how this *always* works, right?
Here’s what’s new:
- **`Maybe.find`:** for those times when you want to do `Array.prototype.find` and would love to not have to wrap up the result with a `Maybe` explicitly every time. As with most functions in True Myth, it’s curried so you can easily use it in a functional programming style.
```ts
import Maybe from 'true-myth/maybe';
let foundRegular = Maybe.find(n => n > 1, [1, 2, 3]);
console.log(foundRegular.toString()); // Just(2)
let notFound = Maybe.find(n = n < 1, [1, 2, 3]);
console.log(notFound.toString()); // Nothing
let findAtLeast5 = Maybe.find((n: number) => n > 5);
let foundCurried = findAtLeastFive([2, 4, 6, 8, 10]);
console.log(foundCurried.toString()); // Just(6)
```
- **`Maybe.head` (aliased as `Maybe.first`):** for getting the first item of an array safely. Like lodash’s `_.head` (or `someArray[0]`) but it returns a `Maybe` instead of possibly giving you back `undefined`.
```ts
import Maybe from 'true-myth/maybe';
let empty = Maybe.head([]);
console.log(empty.toString()); // Nothing
let hasItems = Maybe.head([1, 2, 3]);
console.log(hasItems.toString()); // Just(1)
```
- **`Maybe.last`:** the same as `Maybe.head`, but for getting the *last* element in an array.
```ts
import Maybe from 'true-myth/maybe';
let empty = Maybe.last([]);
console.log(empty.toString()); // Nothing
let hasItems = Maybe.last([1, 2, 3]);
console.log(hasItems.toString()); // Just(3)
```
- **`Maybe.all`:** for converting an array of `Maybe`s to a `Maybe` of an array. If you have an array whose contents are all `Maybe`s, it’s sometimes useful to be able to flip that around so that if all of the items are `Just`s, you get back a single `Just` wrapping the array of the values which were wrapped in all the `Just`s in the array, but if any were `Nothing`, the whole thing is a single `Nothing`. This works for both heterogeneous and homogenous arrays, which is pretty cool. A code sample will make this a lot clearer:
```ts
import Maybe, { just, nothing } from 'true-myth/maybe';
let includesNothing = Maybe.all(just(2), nothing