[bkallus]

Functional languages support this type of operation in a few different ways.

One is through constructs like Clojure's `take-while`. Instead of setting a vairable when you want to exit the loop, you define a predicate that is false when the loop should exit.

Another is through `any` and `all` (aka `some` and `every`), which work in a similar way to `take-while`, except they reduce OR or AND across the returned values from the predicate as they go.

EDIT: grammar and clarity