diff options
Diffstat (limited to 'vendor/itertools/src/zip_eq_impl.rs')
| -rw-r--r-- | vendor/itertools/src/zip_eq_impl.rs | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/vendor/itertools/src/zip_eq_impl.rs b/vendor/itertools/src/zip_eq_impl.rs new file mode 100644 index 00000000..3240a40e --- /dev/null +++ b/vendor/itertools/src/zip_eq_impl.rs @@ -0,0 +1,65 @@ +use super::size_hint; + +/// An iterator which iterates two other iterators simultaneously +/// and panic if they have different lengths. +/// +/// See [`.zip_eq()`](crate::Itertools::zip_eq) for more information. +#[derive(Clone, Debug)] +#[must_use = "iterator adaptors are lazy and do nothing unless consumed"] +pub struct ZipEq<I, J> { + a: I, + b: J, +} + +/// Zips two iterators but **panics** if they are not of the same length. +/// +/// [`IntoIterator`] enabled version of [`Itertools::zip_eq`](crate::Itertools::zip_eq). +/// +/// ``` +/// use itertools::zip_eq; +/// +/// let data = [1, 2, 3, 4, 5]; +/// for (a, b) in zip_eq(&data[..data.len() - 1], &data[1..]) { +/// /* loop body */ +/// # let _ = (a, b); +/// } +/// ``` +pub fn zip_eq<I, J>(i: I, j: J) -> ZipEq<I::IntoIter, J::IntoIter> +where + I: IntoIterator, + J: IntoIterator, +{ + ZipEq { + a: i.into_iter(), + b: j.into_iter(), + } +} + +impl<I, J> Iterator for ZipEq<I, J> +where + I: Iterator, + J: Iterator, +{ + type Item = (I::Item, J::Item); + + fn next(&mut self) -> Option<Self::Item> { + match (self.a.next(), self.b.next()) { + (None, None) => None, + (Some(a), Some(b)) => Some((a, b)), + (None, Some(_)) | (Some(_), None) => { + panic!("itertools: .zip_eq() reached end of one iterator before the other") + } + } + } + + fn size_hint(&self) -> (usize, Option<usize>) { + size_hint::min(self.a.size_hint(), self.b.size_hint()) + } +} + +impl<I, J> ExactSizeIterator for ZipEq<I, J> +where + I: ExactSizeIterator, + J: ExactSizeIterator, +{ +} |
