There is also rust-script[1] which runs "Rust files and expressions as scripts without any setup or compilation step." I wrote a data loader[2] in it for my Observable Framework project and have been very happy with its performance and overall ease including hot-reloading.

[1] https://rust-script.org

[2] https://observablehq.com/framework/loaders#routing

Great write up, perfect to share with people who want to know what makes Rust tick before/without learning it more thoroughly.

What about lifetimes?

A Rust 101 intro does not need to concern itself with lifetimes.

Indeed, overuse of lifetimes is a common novice mistake. In most real-world programs lifetime annotations are very rarely needed.

The worst disaster of nonsensical <'a> exploding everywhere comes from novices trying to use Rust's references to store objects "by reference" in a struct, without understanding that in Rust references have a completely opposite meaning that forbids storing the data.

Still that you can't just avoid to explain lifetimes. There is a lot of code out there witch uses lifetimes