I haven't written as much Rust as I'd like, but one of my favorite things about the language (there's a lot of competition for "favorite" things about Rust, to

I haven't written as much Rust as I'd like, but one of my favorite things about the language (there's a lot of competition for "favorite" things about Rust, to be fair) is the way that types are required in function signatures, but not within functions. So if you can see the declaration of something, you can always tell what it is -- it's right there. But if it's done in a function somewhere, or if you're just trying to get a sense for the types passed around in a library, it's all on the surface of the signatures. I personally find the lack of declared types in python/javascript absolutely debilitating on large projects, so that really appeals to me.