/rust/registry/src/index.crates.io-6f17d22bba15001f/itertools-0.10.5/src/unziptuple.rs

Source (jump to first uncovered line)
/// Converts an iterator of tuples into a tuple of containers.
///
/// `unzip()` consumes an entire iterator of n-ary tuples, producing `n` collections, one for each
/// column.
///
/// This function is, in some sense, the opposite of [`multizip`].
///
/// ```
/// use itertools::multiunzip;
///
/// let inputs = vec![(1, 2, 3), (4, 5, 6), (7, 8, 9)];
///
/// let (a, b, c): (Vec<_>, Vec<_>, Vec<_>) = multiunzip(inputs);
///
/// assert_eq!(a, vec![1, 4, 7]);
/// assert_eq!(b, vec![2, 5, 8]);
/// assert_eq!(c, vec![3, 6, 9]);
/// ```
///
/// [`multizip`]: crate::multizip
pub fn multiunzip<FromI, I>(i: I) -> FromI
where
    I: IntoIterator,
    I::IntoIter: MultiUnzip<FromI>,
{
    i.into_iter().multiunzip()
}

/// An iterator that can be unzipped into multiple collections.
///
/// See [`.multiunzip()`](crate::Itertools::multiunzip) for more information.
pub trait MultiUnzip<FromI>: Iterator {
    /// Unzip this iterator into multiple collections.
    fn multiunzip(self) -> FromI;
}

macro_rules! impl_unzip_iter {
    ($($T:ident => $FromT:ident),*) => (
        #[allow(non_snake_case)]
        impl<IT: Iterator<Item = ($($T,)*)>, $($T, $FromT: Default + Extend<$T>),* > MultiUnzip<($($FromT,)*)> for IT {
            fn multiunzip(self) -> ($($FromT,)*) {
                // This implementation mirrors the logic of Iterator::unzip resp. Extend for (A, B) as close as possible.
                // Unfortunately a lot of the used api there is still unstable (https://github.com/rust-lang/rust/issues/72631).
                //
                // Iterator::unzip: https://doc.rust-lang.org/src/core/iter/traits/iterator.rs.html#2825-2865
                // Extend for (A, B): https://doc.rust-lang.org/src/core/iter/traits/collect.rs.html#370-411

                let mut res = ($($FromT::default(),)*);
                let ($($FromT,)*) = &mut res;

                // Still unstable #72631
                // let (lower_bound, _) = self.size_hint();
                // if lower_bound > 0 {
                //     $($FromT.extend_reserve(lower_bound);)*
                // }

                self.fold((), |(), ($($T,)*)| {
                    // Still unstable #72631
                    // $( $FromT.extend_one($T); )*
                    $( $FromT.extend(std::iter::once($T)); )*
                });
                res
            }
        }
    );
}

impl_unzip_iter!();
impl_unzip_iter!(A => FromA);
impl_unzip_iter!(A => FromA, B => FromB);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ, K => FromK);
impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ, K => FromK, L => FromL);

Coverage Report

Created: 2025-02-25 06:39

Line	Count	Source (jump to first uncovered line)
1		/// Converts an iterator of tuples into a tuple of containers.
2		///
3		/// `unzip()` consumes an entire iterator of n-ary tuples, producing `n` collections, one for each
4		/// column.
5		///
6		/// This function is, in some sense, the opposite of [`multizip`].
7		///
8		/// ```
9		/// use itertools::multiunzip;
10		///
11		/// let inputs = vec![(1, 2, 3), (4, 5, 6), (7, 8, 9)];
12		///
13		/// let (a, b, c): (Vec<_>, Vec<_>, Vec<_>) = multiunzip(inputs);
14		///
15		/// assert_eq!(a, vec![1, 4, 7]);
16		/// assert_eq!(b, vec![2, 5, 8]);
17		/// assert_eq!(c, vec![3, 6, 9]);
18		/// ```
19		///
20		/// [`multizip`]: crate::multizip
21	0	pub fn multiunzip<FromI, I>(i: I) -> FromI
22	0	where
23	0	I: IntoIterator,
24	0	I::IntoIter: MultiUnzip<FromI>,
25	0	{
26	0	i.into_iter().multiunzip()
27	0	}
28
29		/// An iterator that can be unzipped into multiple collections.
30		///
31		/// See [`.multiunzip()`](crate::Itertools::multiunzip) for more information.
32		pub trait MultiUnzip<FromI>: Iterator {
33		/// Unzip this iterator into multiple collections.
34		fn multiunzip(self) -> FromI;
35		}
36
37		macro_rules! impl_unzip_iter {
38		($($T:ident => $FromT:ident),*) => (
39		#[allow(non_snake_case)]
40		impl<IT: Iterator<Item = ($($T,))>, $($T, $FromT: Default + Extend<$T>), > MultiUnzip<($($FromT,)*)> for IT {
41	0	fn multiunzip(self) -> ($($FromT,)*) {
42	0	// This implementation mirrors the logic of Iterator::unzip resp. Extend for (A, B) as close as possible.
43	0	// Unfortunately a lot of the used api there is still unstable (https://github.com/rust-lang/rust/issues/72631).
44	0	//
45	0	// Iterator::unzip: https://doc.rust-lang.org/src/core/iter/traits/iterator.rs.html#2825-2865
46	0	// Extend for (A, B): https://doc.rust-lang.org/src/core/iter/traits/collect.rs.html#370-411
47	0
48	0	let mut res = ($($FromT::default(),)*);
49	0	let ($($FromT,)*) = &mut res;
50	0
51	0	// Still unstable #72631
52	0	// let (lower_bound, _) = self.size_hint();
53	0	// if lower_bound > 0 {
54	0	// $($FromT.extend_reserve(lower_bound);)*
55	0	// }
56	0
57	0	self.fold((), \|(), ($($T,)*)\| {
58	0	// Still unstable #72631
59	0	// $( $FromT.extend_one($T); )*
60	0	$( $FromT.extend(std::iter::once($T)); )*
61	0	}); Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<()>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_,)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _, _)>>::multiunzip::{closure#0} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _, _, _)>>::multiunzip::{closure#0}
62	0	res
63	0	} Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<()>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_,)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _, _)>>::multiunzip Unexecuted instantiation: <_ as itertools::unziptuple::MultiUnzip<(_, _, _, _, _, _, _, _, _, _, _, _)>>::multiunzip
64		}
65		);
66		}
67
68		impl_unzip_iter!();
69		impl_unzip_iter!(A => FromA);
70		impl_unzip_iter!(A => FromA, B => FromB);
71		impl_unzip_iter!(A => FromA, B => FromB, C => FromC);
72		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD);
73		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE);
74		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF);
75		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG);
76		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH);
77		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI);
78		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ);
79		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ, K => FromK);
80		impl_unzip_iter!(A => FromA, B => FromB, C => FromC, D => FromD, E => FromE, F => FromF, G => FromG, H => FromH, I => FromI, J => FromJ, K => FromK, L => FromL);