Yep, it’s another technical episode. I promise soon I’ll tell y’all about Felix. He’s s good dog.
But today we’re talking about building services that run in data centers and provide some slice of the information you see when you log into a web site. How those services are made will mostly be felt to you by how fast the site responds.
A lot of this stuff is written Java, or Microsoft’s shameless copy C# (pronounced c-sharp). I was a fan of Java back in the day, but it failed in its core premise “write once, run everywhere” and became instead a not-awful language everyone used on servers. The only reason I can figure this is: It’s harder to make a terrible mistake in java than in C++.
I built a thing in Java that has yet to be reproduced. So I say this to Java with love: You are done. You did not fulfill your original promise, and there are much better languages to be running in servers. The absolute monstrosity that is SpringBoot reinforces that fact.
If you’re going to write a service that runs in the cloud, even PHP is better than Java. (We will not speak further of .NET). But the top three? You’ve got Go, Rust, and Swift. This is an opinionated comparison.
Go: Google’s baby. It is all about a simple syntax for tasks that can run in parallel. ‘go’ do this thing and give us the result when you are done.
Rust: Mozilla’s baby. It is all about memory management. It is uncompromising to the extent that “memory leak”, a bugaboo of services, is impossible. Because of its architecture, it’s a hard target for hackers.
Swift: Apple’s baby. Almost as hard-assed as Rust. With some effort you can apply the memory principles in Rust, but not at the deep compiler level. Running tasks in parallel is an add-on, rather than the effortless Go.
My biased opinion:
I have more than once looked at Go, and asked, “where’s the rest?” Surely I must be missing something. But apparently I’m not. There’s just not that much here. A well-considered language should encourage good patterns. Go has interface, at least, and now has picked up generics, but remains skimpy. “Simpler is better”, the Goog declares, and if that’s your bag of beans, then maybe Go is for you. But… no optionals?
Rust. Hardcore shit. They ask you to tune your thoughts to a different frequency and you will know the rewards. I’m not saying they’re wrong. If you will indulge me…
A Brief Aside — Memory. When a program runs, it puts data into memory in a place everyone who is interested can find it.
- C/C++ requires that in your code, every place you allocate memory, you must have a matching process to free it up again. This is the single thing that made Java popular — it lifted that burden from the programmer.
- Go has a garbage collector: each item in memory keeps a list of everyone who is interested in it. When no one is interested, the garbage collector comes along and releases that memory for use by anyone else. This means that everything stops for a very brief time for the garbage collector to do its work.
- Swift also counts the number of things interested in a chunk of information, but when that count goes to zero it immediately frees the memory. This means whenever something goes out of scope checks must be made.
- Rust, however, makes sure that only one thing owns that chunk of memory, and when that thing is done, the chunk is gone. Fast, simple, precise. But it means you have to code in a particular way. Who owns this? will eventually become second nature, but it’s a climb to get there.
So that’s Rust. It’s pretty cool. Big names are using Rust in critical services — including the people who invented Go.
That leaves Swift. Generally dismissed as the language to make iPhone apps, it is fundamentally grounded in the belief that a programming language should make it as difficult as possible to make mistakes. Common errors that cost the world billions of dollars a year simply won’t compile in Swift.
But Swift is bigger (in scope, not popularity) than the others. It has the semantics for running many things at once, and if they aren’t as native to Swift and Rust as they are to Go, they still work just fine. It also has deep semantics for inheritance and composition (strongly favoring composition), along with generics, closures, and of course type-safety. Even JavaScript has a type-safe version.
Mmm… delicious type-safe closures.
I’ve been writing Web services for a while now, and I choose Swift. Rust might be incrementally faster, but it might not; it depends on the specific application. Swift compiles up to be fast. Go just doesn’t have the constructs I need to make a good server. Maybe for simple CRUD it’s all right, but I wouldn’t want to write serious business logic using it. Too much not there.
