[estebank]

Identifiers in Rust can't have dashes (rustc will never rely on whitespace for proper tokenization). It is arguable that because of that crates should not have dashes in their name. cargo was changed to automatically convert dashes to underscores for convenience because some dislike underscores in names. I personally think this is an unnecessary source of confusion and now I would make all tools (mainly cargo) treat them interchangeably.

[a1369209993]

> rustc will never rely on whitespace for proper tokenization

Huh? That seems clearly untrue, eg `fnfoo` vs `fn foo` or `x && y` vs `x & &y` or `x<<shift_or_type > ::foo` vs `x < <shift_or_type>::foo`? Presumably for some or all of those, one version ends up being a error (eg bitwise and with a pointer from `x & &y` probably doesn't work), but that's not at the level of tokenization.

[ChrisSD]

Given the context, I think they simply mean that a-b is interpreted the same as a - b.

It can't be interpreted as a single identifier.