Just a few thoughts on programming languages that have been rattling around in my head this week, but which don’t each merit a full blog post. The main theme is that the culture behind each programming language leads to some interesting choices, as is the case with spoken languages.

This week I started learning how to program in Rust. Even though I’m using the project-based Command-Line Rust to learn, the author still went with the traditional “Hello, world!” project for the first intro to the language. I was also working on a Go project last week and so it immediately stood out to me that (at least as taught by this author) Rust has the print! macro that allows you to succinctly print to the command line. By contrast, Go requires importing fmt before you can print. This was the first topic that was swirling around in my head this week. What makes language designers choose whether printing output (one of the most basic things a program can do) is built-in or requires an import. I even remember back when I was learning Java in undergrad (I think it was Java 1.8, but I don’t remember) we had to use the savitch library just to get program input (another very basic computer program concept). As I thought about it, I wondered if it has to do with thoughts around compilation and whether the language designers think you’re mostly making user-interactive programs or libraries? It makes sense to me that scripting languages like Python, Ruby, and Perl would have print built-in since you always have to have the interpreter along with you, so all the basics should be there. (The original Batteries Included Python promise, for example) But perhaps the Go developers thought you wouldn’t always be printing to the command line so a more efficient binary could be compiled by forcing you to import the functionality? I’m not entirely sure. 

The next thing I started thinking about, again due to learning Rust, was the mutability of variables. In most languages I’ve come across (I think all, except Haskell) all variables are mutable by default. It almost seems pointless to have a non-mutable variable. I understand why many languages have the concept of a “contanst” modifier/keyword. Unlike normal variables, THIS ONE does not change. But the opposite seems so weird since most of what we often do in programming involves changing the value in a variable. Perhaps as I learn more about Rust, I’ll understand their reasoning, but this seems completely backwards to me.

Both Rust and Golang use structs to organize variables where Ruby, Python, and Java use objects. But when both Go and Rust allow you to “attach” methods/functions to structs – is there a true distinction between object-oriented programming and struct-based programming? It seems like it’s just semantics (in the generic sense of the word) – at least at the level at which I program. The only difference I can see is that structs don’t have inheritance, although Go’s “types” solve some of the same problems.

Today’s (the day I’m writing this, not the day it’s going to be posted) shower thought was about programming language versions. On one end you have Java (I think now on version 22) and C# (now at version 12). On the other you have Python and Ruby (both at version 3). Perl essentially stopped at 5 with Perl 6 evolving into Raku. I don’t know what Java is up to. But I think C# is actually using the versions correctly – I’ve heard that each version introduces completely different ways of doing things and that the way you program C# depends strongly on when you jumped in. This is why Python is probably never moving to v4 unless they need to make some kind of huge change. Rust is an outlier with year-based versions. I guess that’s fine, but doesn’t tell you anything like a proper semantic versioning could. 

Finally, I know that Rust is the newest of all the programming languages I’ve learned, but I really love how new projects are started. Python isn’t horrible, but it’s currently suffering from a lots of ideas, none of which has complete market share. You could do a simple virtual environment or you could do a more complex virtual environment/lock file situation with Poetry. (And there are about another half dozen variations on these two themes) But Rust….Rust deserves a chef’s kiss. When you start a new project with “cargo new project-name”, not only does it set up your directory structure, but it does a whole bunch of great setup tasks. It creates your Cargo.toml file (with Python, which only really started supporting toml files at the project level a few years ago, you need to look at documentation to figure out what goes in there) so that you have all the basics in there already. But it doesn’t stop there! It also, in a nod to modern programming, creates a git repository AND a gitignore file. It’s a thing of beauty. I would absolutely love for Python to move in this direction officially (not through a random user choice) for their defaults. Even “go mod init” could benefit from setting up a git repo and a git ignore (since the toml is not how Go works – I think they would probably best set up a README.md since Go’s default packaging is through git repos).