The Core of Rust

Summary

NOTE: this is not a rust tutorial. Every year it was an incredible challenge to fit teaching Rust into lectures since you basically need all the concepts right from the start to understand a lot of programs. I never knew how to order things. The flip side was that usually when you understand all the basic components in play lots of it just fits together. i.e. there's some point where the interwovenness turns from a barrier into something incredibly valuable and helpful. —Jana Dönszelmann Vision One thing I admire in a language is a strong vision. Uiua, for example, has a very strong vision: what does it take to eliminate all local named variables from a language? Zig similarly has a strong vision: explicit, simple language features, easy to cross compile, drop-in replacement for C. Note that you don’t have to agree with a language’s vision to note that it has one. I expect most people to find Uiua unpleasant to program in. That’s fine. You are not the target audience. There’s a famous quote by Bjarne Strousup that goes “Within C++, there is a much smaller and cleaner language struggling to get out.” Within Rust, too, there is a much smaller and cleaner language struggling to get out: one with a clear vision, goals, focus. One that is coherent, because its features cohere. This post is about that language. Learning Rust requires learning many things at once Rust is hard to learn. Not for lack of trying—many, many people have spent person-years on improving the diagnostics, documentation, and APIs—but because it’s complex. When people first learn the language, they are learning many different interleaving concepts: first class functions enums pattern matching generics traits references the borrow checker Send/Sync Iterators These concepts interlock. It is very hard to learn them one at a time because they interact with each other, and each affects the design of the others. Additionally, the standard library uses all of them heavily. Let’s look at a Rust program that d...