yield used outside a generator

Why this fires¶

yield is only valid in a generator declared with fn*. An ordinary or async fn returns one result; it does not expose a pull iterator.

fn values() { yield 1 } // TE221

Fix it¶

Use fn* when the function is intended to produce a sequence:

fn* values() -> int {
    yield 1
}

Calling this function returns Iter<int>. If only one value is needed, replace yield value with the function's ordinary return or tail value.