Function next

libs/error-stack/src/iter.rs:33–48

Helper function, which is used in both [`Frames`] and the mutable frame traversals on [`Report`]. [`Report`]: crate::Report To traverse the frames, the following algorithm is used: Given a list of iterators, take the last iterator, and use items from it until the iterator has been exhausted. If that is the case (it returned `None`), remove the iterator from the list, and continue with the next i

(iter: &mut Vec<I>)

/// 8) Out: H Stack: -
/// ```
pub(crate) fn next<I: Iterator<Item = T>, T>(iter: &mut Vec<I>) -> Option<T> {
    let out;
    loop {
        let last = iter.last_mut()?;

        if let Some(next) = last.next() {
            out = next;
            break;
        }

        // exhausted, therefore cannot be used anymore.
        iter.pop();
    }

    Some(out)
}

/// Iterator over the [`Frame`] stack of a [`Report`].
///