The three rewrites Vanadium went through

June 22, 2025

If you take a peek at Vanadium’s commit history, you will see two interesting commits:

54fb61d: feat: effing RWR (Rewrite it In Rust)
d8e6af7: feat: rewrite in C++ (I PROMISE IT'S THE FINAL REWRITE!)

And this is because Vanadium has changed development language two times.

Zig

It was first going to be made in Zig, but I realized that I was going too slow and the code was too messy, refactoring was too hard at that moment, so I decided to archive the version and try to make it in Rust.

What I had for that version:

A full lexer.
Already started doing the parser.

Rust

When I noticed Zig wouldn’t work, I changed to Rust.

I chose Rust because it’s a very robust language, it has very good tooling, and it’s overall a very good option. Then I noticed that I don’t know anything about Rust, I thought it was going to be easy coming from C++, but it seems that it didn’t really work at the end. I was messing around with types, trying to understand all the weird errors, until I just admitted that Rust wasn’t going to work.

C++

If Zig didn’t work because it became too complex very fast, and Rust didn’t work because it has a very steep learning curve and I couldn’t start coding in it by developing a language then I needed to go for something familiar, something that I already knew how to use, so I chose C++.

Vanadium is now being developed in C++, and it will remain like that until…

Self-hosting?

In the future, I will probably try self-hosting. Self-hosting basically consists of:

Writing a stage-one compiler in C++ (already on it).
Writing a stage-two compiler in Vanadium to act as main compiler.
Compile the stage-two compiler with the stage-one (or bootstrap) compiler.
Distribute the compiled stage-two.

This allows for me to first go through the pain of making Vanadium in C++, then adding new features in Vanadium, which is less painful, and also allows for rewriting all the logic already made in C++ in Vanadium so it can be refined.

The inspiration for making Vanadium self-hosted in the future was Zig. Zig has a 97.6% of Zig code in it’s source code, the current stage-one compiler it’s only 2.1% of the source code. Other languages that did this (and far sooner than Zig) are:

C, originally written in Assembly.
Rust, originally written in OCaml.