From f198b0acf512458bdbe5079d12414ff94b03f7ac Mon Sep 17 00:00:00 2001 From: Sean Silva Date: Sat, 24 Mar 2018 22:31:17 -0700 Subject: [PATCH] Fix confusing doc for `scan` The comment "the value passed on to the next iteration" confused me since it sounded more like what Haskell's [scanl](http://hackage.haskell.org/package/base-4.11.0.0/docs/Prelude.html#v:scanl) does where the closure's return value serves as both the "yielded value" *and* the new value of the "state". I tried changing the example to make it clear that the closure's return value is decoupled from the state argument. --- src/libcore/iter/iterator.rs | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/src/libcore/iter/iterator.rs b/src/libcore/iter/iterator.rs index 2cfbc092293..31f77f92435 100644 --- a/src/libcore/iter/iterator.rs +++ b/src/libcore/iter/iterator.rs @@ -974,13 +974,13 @@ pub trait Iterator { /// // each iteration, we'll multiply the state by the element /// *state = *state * x; /// - /// // the value passed on to the next iteration - /// Some(*state) + /// // then, we'll yield the negation of the state + /// Some(-*state) /// }); /// - /// assert_eq!(iter.next(), Some(1)); - /// assert_eq!(iter.next(), Some(2)); - /// assert_eq!(iter.next(), Some(6)); + /// assert_eq!(iter.next(), Some(-1)); + /// assert_eq!(iter.next(), Some(-2)); + /// assert_eq!(iter.next(), Some(-6)); /// assert_eq!(iter.next(), None); /// ``` #[inline]