Fish 4.0 completes the move from C++ to Rust.

Fish is a fantastic shell with tab completions, syntax highlighting, autocomplete, and lots more. It’s been my daily driver for at least 5 years now. If you depend on Bash scripts you can use Bass to load them.

Great tooling makes development fun — very important in a hobby project:

We need to get one thing out of the way: Rust is cool. It’s fun.

It’s tempting to try to sweep this under the rug because it feels gauche to say, but it’s actually important for a number of reasons.

For one, fish is a hobby project, and that means we want it to be fun for us. Nobody is being paid to work on fish, so we need it to be fun. Being fun and interesting also attracts contributors.

Rust also has great tooling. The tools have really paid a lot of attention to use, and the compiler errors are terrific. Not even “compared to C++”, they just actually rule. And as we have tried to pay attention to our own error messages (fish has a bespoke error for if it thinks a file you told it to run has Windows line endings), we like it.

And it is easy to get that tooling installed – rustup is magic, and allows people to get started quickly, with minimal fuss or root permissions. When the answer to “how to upgrade C++ compiler” is “find a repository (with root permissions), compile it yourself, install some other repository or a docker image”, it is amazing how the Rust answer can just be “use rustup”.

Rust has great ergonomics – the difference between C++’s pointers (which can always be NULL) and Rust’s Options are apparent very quickly even to those of us who had never used it before. We did have a backport of C++’s optional, and liked using it, but it was never as integrated as Rust’s Options were.

Great tools lead to great projects.

While we’re talking about shells, you might want to try Ghostty, Berkeley Mono, and Fastfetch to kick off 2025.