Haxe is one of those languages that I’ve followed for a long time. Not only that, but it’s the rare programming language that I actually like. There aren’t too many on that list: C++, Scala, Haxe, Python 2 (but not 3!), and…that’s just about it.
(As much as I write about JavaScript, I only tolerate it because of its popularity and general usefulness. I don’t like Java for a number of reasons—I’ll do a “languages I hate” post one of these days—but it’s the only language I’ve written professionally. I like the idea of C# and TypeScript, but they both have the problem of being Microsoft-controlled. And so on.)
About the language
Anyway, back to Haxe, because I genuinely feel that it’s a good programming language. First of all, it’s strongly-typed, and you know my opinion on that. But it’s also not so strict with typing that you can’t get things done. Haxe also has type inference, and that really, really helps you work with a strongly-typed language. Save time while keeping type safety? Why not?
In essence, the Haxe language itself looks like a very fancy JavaScript. It’s got all the bells and whistles you expect from a modern language: classes, generics, object literals, array comprehensions, iterators, and so on. You know, the usual. Just like everybody else.
But there’s also a few interesting features that aren’t quite as common. Pattern matching, for instance, which is one of my favorite things from “functional” languages. Haxe also has the idea of “static extensions”, something like C#’s extension methods, which allow you to add extra functionality to classes. Really, most of the bullet points on the Haxe manual’s “Language Features” section are pretty nifty, and most of them are in some way connected to the type system. Of any language I’ve ever used, only Scala comes close to helping me understand the power and necessity of types as much as Haxe.
The platform
But wait, there’s more. Haxe is cross-platform, in its own special way. Strictly speaking, there’s no native output. Instead, you have a choice of compilation targets, and some of these can then be turned into native binaries. Most of these let you “transpile” Haxe code to another language: JavaScript, PHP, C++, C#, Java, and Python. There’s also the Neko VM, made by Haxe’s creator but not really used much, and you can even have the Haxe compiler spit out ActionScript code or a Flash SWF. (Why you would want to is a question I can’t answer.)
The standard library provides most of what you need for app development, and haxelib is the Haxe-specific answer to NPM, CPAN, et al. A few of the available libraries are very good, like OpenFL (basically a reimplementation of the Flash API). Of course, depending on your target platform, you might also be able to use libraries from NPM, the JVM, or .NET directly. It’s not as easy as it could be—you need an extern interface class, a bit like TypeScript—but it’s there, and plenty of major libraries are already fixed for you.
The verdict
Honestly, I do like Haxe. It has its warts, but it’s a solid language that takes an idea (types as the central focus) and runs with it. And it draws in features from languages like ML and Haskell that are inscrutable to us mere mortals, allowing people some of the power of those languages without the pain that comes in trying to write something usable in a functional style. Even if you only use it as a “better” JavaScript, though, it’s worth a look, especially if you’re a game developer. The Haxe world is chock full of code-based 2D game engines and libraries: HaxePunk, HaxeFlixel, and Kha are just a few.
I won’t say that Haxe is the language to use. There’s no such thing. But it’s far better than a lot of the alternatives for cross-platform development. I like it, and that’s saying a lot.