Native pattern matching for Javascript.

Usage

• install via npm: npm install z
• require z in your code, and name the match function as you want!

const matches = require('z')

• you can match by comparing values

const person = { name: 'Johna' }
matches(person)(
  (x = { name: 'John' }) => console.log('John you are not welcome!'),
  (x)                    => console.log(`Hey ${x.name}, you are welcome!`)
)

• you can match by comparing types or instances

matches(1)(
  (x = 2)      => console.log(`number 2 is the best!!!`),
  (x = Number) => console.log(`number ${x} is not that good`),
  (x = Date) => console.log(`blaa.. strings are awful!`)
)

• on arrays, you can split head and tail, so you can do awesome recurring functions! , without manipulating arrays or changing state. Yes true functional programming in JavaScript!

const reverse = (list) => matches(list)(
  (head, tail = []) => [head], // stopping condition
  (head, tail)      => myReverse(tail).concat(head)
)


reverse([1, 2, 3, 4])) // returns [4, 3, 2, 1]

Available Patterns

• Matches by value: (x = 1) =>, (x = null) =>, (x = 'true') =>
• Matches by object and array: (x = {a: 1}) =>, (x = [1, 2]) =>
• Matches by type: (x = String) =>, (x = Boolean) =>
• Matches by instance: (x = Date) =>, (x = Person) =>
• Matches spiting array into head and tail (head, tail) =>, it can be multiple heads, eg.: (x, y, z, xs), (a, b, c, d, e, f, g, tail), etc...

This is amazing! Why nobody did this before on JavaScript?

He did, years ago! But his first and greater Javascript pattern match library create matches with strings, and this is ugly! (sorry). Maybe he thought this is ugly too and he did a new pattern matching library without strings, but need to install some macro stuff.. and well, I don't think that's nice either.

Why z was created? Because IT'S B E A U T I F U L: No need to install nothing but the actual z library, the matches are real native javascript code, the patterns are written naturally, pure ❤️.

The project is new and growing!

Suggestions, bug reports and pull requests are welcomed!