Written by Ramon Gebben

Squiggle (GitHub: wavebeem/squiggle, License: MIT, npm: squiggle-lang)

Squiggle is a strict, expression-oriented, compile-to-JS programming language. Yes, yet another compile-to-JS language. At the beginning I was sceptic about it, but once I started reading the tutorial posted on the site I adjusted my opinion. Not everything is there yet, but I need to say that I like the way it looks and might even consider picking it up.

So some of the features that drew my attention are:

  • Arity checked functions
    • When calling a function created in Squiggle with not enough arguments, it throws an exception.
  • Frozen literals
    • Array and object literals are frozen with Object.freeze by default, so you can’t accidentally mutate them.
  • Easy updates
    • Operators ++ to concatenate two arrays or two strings, and ~ to merge two objects into a new frozen object with the prototype of the first object.
  • Destructuring assignment
    • Grab object properties or array elements when you assign variables, like: let [x, y] = [1, 2] or let {x, y} = {x: 1, y: 2}.
  • Pattern matching
    • Is similar to the Javascript switch but with destructuring power built-in and no dangerous fall-through.
  • No type coercion
    • Standard operators like +, -, *, and more, have been replaced with strict version that do not perform any type coercions, throwing exceptions on bad inputs.
  • Deep equality
    • The operator == performs a deep equality check.

There are a lot more features which just make it work a bit nicer. If you want a good overview of what this language can do I would recommend you reading the tutorial section of the website and then give it a shot in the browser.

Here is a small example provided by the developer in which you can see how it would work together met Node’s HTTP package.

let http = require "http"

let port = 1337
let host = ""

def handler(res, res) =
    let headers = {"Content-Type": "text/plain"}
    let _ = res.writeHead(200, headers)
    let _ = res.end("Hello world\n")
    in undefined

let server = http.createServer(handler)
let _ = server.listen(port, host)
let _ = console.log("Server running at http://" ++ host + ":" ++ port ++ "/")
in undefined

Since there is a comment section present after the latest update, I would love to here what you guys think of this and the blog in general.