### Location <https://doc.rust-lang.org/reference/expressions/loop-expr.html#iterator-loops> ### Context I was reviewing a test cleanup PR https://github.com/rust-lang/rust/pull/141974, and I was trying to say something about the `EXPR` in ```rs for PATTERN in EXPR { // ^--- what is this expr called? // ... } ``` but I couldn't find a good term for this[^1][^2]. The current grammar calls this `EXPR` > [Expression](https://doc.rust-lang.org/reference/expressions.html)<sub>except struct expression</sub> whereas for e.g. `match EXPR { .. }` or `if let PATTERN = EXPR { .. }`, there's a more "meaningful name" for that `EXPR`, which is the scrutinee expr. [^1]: In the community discord, terms like "interatee" or "iterable" or "into-iterable" were suggested, but yeah. [^2]: Nadrieril came up with "loopee", which is an excellent term 😆