Rust and Swift (v)

The value (and challenge) of learning languages in parallel.

September 12, 2015Filed under Tech#programming languages#rust#rust-and-swift#software development#swiftMarkdown source

I am reading through the Swift book, and comparing it to Rust, which I have also been learning over the past month. As with the other posts in this series, these are off-the-cuff impressions, which may be inaccurate in various ways. I’d be happy to hear feedback! Note, too, that my preferences are just that: preferences. Your tastes may differ from mine. (See all parts in the series.)


I’ve been working on learning Swift over the past couple weeks, and had spent the month prior to that doing a deep first dive on Rust. This kind of approach, learning two languages basically at the same time, is entirely new to me, and for good reason. Programming languages are not trivial to learn, and to learn them meaningfully one must practice with them a great deal.

I’m doing this largely of necessity. I’m hoping to build an application with a very capable, performant cross-platform core language (Rust), but planning to ship a native OS X app (first) when all is said and done. My desire to make the core libraries portable rules out Swift immediately. To be frank, so does the fact that it’s an Apple language: I am happy to use Apple’s tools on its platform, but I don’t want to shackle myself to their choices in the long run. Too, having good Rust experience is likely to be valuable in many other contexts.

So I need to learn both.

And, while I wouldn’t ordinarily recommend this course of action—indeed, unless you already have a fair bit of programming experience and already know several languages, I’d actively recommend against it—I’m finding it enormously profitable. The languages have been designed in roughly the same time frame, cite many of the same influences, and overlap substantially in terms of audience and goals. Yet they are, as this series has already highlighted, quite different languages in many ways.

Learning them in parallel is helping me see the trade-offs each one has made, and force me to think about why they differ in the ways they do. In particular, I think I have a much better idea what’s going on “under the covers” in each language and therefore know what to expect of them better. This, in turn, has dramatically deepened my grasp of the languages relative to the amount I’ve been looking at them, compared to previous language-learning efforts. (It also helps that I’ve already learned a number of languages, of course, and that I’ve been pushing my brain into the learning-programming-languages space via reading about Haskell, functional patterns in JavaScript, and so on this year.)

I have a long way to go in both languages, of course. Reading on nights and weekends, and the little bit of playing I’ve been able to do with each of them, is no replacement for just sinking my teeth into a project and finding the pain points. Nonetheless, I’m really glad to be learning these two languages together. If you’re up for a challenge, try it sometime! You’ll be surprised how much you learn.