Function normalize 

pub fn normalize(name: &str) -> String

The key a crate name is stored and searched under: ASCII-lowercased, with - and _ folded together — the same way crates.io decides whether two names collide.

crates.io rejects a new crate whose folded name matches an existing one, so this key is unique across the registry — which is what lets the artifacts be sorted by it and still be searched with a binary search. Names keep their original spelling in the artifact; only the ordering and the comparisons are folded.