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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/itertools/src/zip_eq_impl.rs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/itertools/src/zip_eq_impl.rs')
-rw-r--r-- | third_party/rust/itertools/src/zip_eq_impl.rs | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/third_party/rust/itertools/src/zip_eq_impl.rs b/third_party/rust/itertools/src/zip_eq_impl.rs new file mode 100644 index 0000000000..a079b326a4 --- /dev/null +++ b/third_party/rust/itertools/src/zip_eq_impl.rs @@ -0,0 +1,60 @@ +use super::size_hint; + +/// An iterator which iterates two other iterators simultaneously +/// +/// 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, +} + +/// Iterate `i` and `j` in lock step. +/// +/// **Panics** if the iterators 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 */ +/// } +/// ``` +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 +{} |