This is significantly simplified from the version in the book, since
I'm using Rust's Vec and not implementing dynamic arrays manually.
We'll see if I run into issues with that ...
Change-Id: Ie3446ac3884b850f3ba73a4b1a6ca14e68054188
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2413
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
