[aw1621107]

> Go aims at abstraction at the package level. Each package exports a set of types and functions which are "magic" to outsiders and can be used by outsiders - an API, if you will. Rust seems to aim at abstraction at the line level - each line is an abstract "magic" representation of what it is meant to do.

Are line-level vs. package-level abstractions are necessarily mutually exclusive? One could argue that the functions Rust iterators expose are "'magic' to outsiders and can be used by outsiders --- an API, if you will".

> but I have no clue how it does it

The question here is whether it actually matters whether you know how the Rust code works. You don't necessarily need to know how `range` or `append` work; you just need to know what they do. Why should the Rust code be held to a different standard in this case?