diff options
| -rw-r--r-- | library/core/src/iter/traits/iterator.rs | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/library/core/src/iter/traits/iterator.rs b/library/core/src/iter/traits/iterator.rs index 275412b57b5..3e9521713aa 100644 --- a/library/core/src/iter/traits/iterator.rs +++ b/library/core/src/iter/traits/iterator.rs @@ -1380,8 +1380,8 @@ pub trait Iterator { Take::new(self, n) } - /// An iterator adapter similar to [`fold`] that holds internal state and - /// produces a new iterator. + /// An iterator adapter which, like [`fold`], holds internal state, but + /// unlike [`fold`], produces a new iterator. /// /// [`fold`]: Iterator::fold /// @@ -1393,20 +1393,25 @@ pub trait Iterator { /// /// On iteration, the closure will be applied to each element of the /// iterator and the return value from the closure, an [`Option`], is - /// yielded by the iterator. + /// returned by the `next` method. Thus the closure can return + /// `Some(value)` to yield `value`, or `None` to end the iteration. /// /// # Examples /// /// Basic usage: /// /// ``` - /// let a = [1, 2, 3]; + /// let a = [1, 2, 3, 4]; /// /// let mut iter = a.iter().scan(1, |state, &x| { - /// // each iteration, we'll multiply the state by the element + /// // each iteration, we'll multiply the state by the element ... /// *state = *state * x; /// - /// // then, we'll yield the negation of the state + /// // ... and terminate if the state exceeds 6 + /// if (*state > 6) { + /// return None; + /// } + /// // ... else yield the negation of the state /// Some(-*state) /// }); /// |