Merging upstream version 1.76.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 174 insertions, 55 deletions

diff --git a/vendor/itertools/src/merge_join.rs b/vendor/itertools/src/merge_join.rs
index 84f7d0333..c83159186 100644
--- a/vendor/itertools/src/merge_join.rs
+++ b/vendor/itertools/src/merge_join.rs
@@ -1,40 +1,111 @@
 use std::cmp::Ordering;
-use std::iter::Fuse;
 use std::fmt;
+use std::iter::{Fuse, FusedIterator};
+use std::marker::PhantomData;
 
 use either::Either;
 
-use super::adaptors::{PutBack, put_back};
+use super::adaptors::{put_back, PutBack};
 use crate::either_or_both::EitherOrBoth;
 use crate::size_hint::{self, SizeHint};
 #[cfg(doc)]
 use crate::Itertools;
 
+#[derive(Clone, Debug)]
+pub struct MergeLte;
+
+/// An iterator adaptor that merges the two base iterators in ascending order.
+/// If both base iterators are sorted (ascending), the result is sorted.
+///
+/// Iterator element type is `I::Item`.
+///
+/// See [`.merge()`](crate::Itertools::merge_by) for more information.
+pub type Merge<I, J> = MergeBy<I, J, MergeLte>;
+
+/// Create an iterator that merges elements in `i` and `j`.
+///
+/// [`IntoIterator`] enabled version of [`Itertools::merge`](crate::Itertools::merge).
+///
+/// ```
+/// use itertools::merge;
+///
+/// for elt in merge(&[1, 2, 3], &[2, 3, 4]) {
+///     /* loop body */
+/// }
+/// ```
+pub fn merge<I, J>(
+    i: I,
+    j: J,
+) -> Merge<<I as IntoIterator>::IntoIter, <J as IntoIterator>::IntoIter>
+where
+    I: IntoIterator,
+    J: IntoIterator<Item = I::Item>,
+    I::Item: PartialOrd,
+{
+    merge_by_new(i, j, MergeLte)
+}
+
+/// An iterator adaptor that merges the two base iterators in ascending order.
+/// If both base iterators are sorted (ascending), the result is sorted.
+///
+/// Iterator element type is `I::Item`.
+///
+/// See [`.merge_by()`](crate::Itertools::merge_by) for more information.
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+pub struct MergeBy<I: Iterator, J: Iterator, F> {
+    left: PutBack<Fuse<I>>,
+    right: PutBack<Fuse<J>>,
+    cmp_fn: F,
+}
+
+/// Create a `MergeBy` iterator.
+pub fn merge_by_new<I, J, F>(a: I, b: J, cmp: F) -> MergeBy<I::IntoIter, J::IntoIter, F>
+where
+    I: IntoIterator,
+    J: IntoIterator<Item = I::Item>,
+{
+    MergeBy {
+        left: put_back(a.into_iter().fuse()),
+        right: put_back(b.into_iter().fuse()),
+        cmp_fn: cmp,
+    }
+}
+
 /// Return an iterator adaptor that merge-joins items from the two base iterators in ascending order.
 ///
 /// [`IntoIterator`] enabled version of [`Itertools::merge_join_by`].
-pub fn merge_join_by<I, J, F, T>(left: I, right: J, cmp_fn: F)
-    -> MergeJoinBy<I::IntoIter, J::IntoIter, F>
-    where I: IntoIterator,
-          J: IntoIterator,
-          F: FnMut(&I::Item, &J::Item) -> T,
-          T: OrderingOrBool<I::Item, J::Item>,
+pub fn merge_join_by<I, J, F, T>(
+    left: I,
+    right: J,
+    cmp_fn: F,
+) -> MergeJoinBy<I::IntoIter, J::IntoIter, F>
+where
+    I: IntoIterator,
+    J: IntoIterator,
+    F: FnMut(&I::Item, &J::Item) -> T,
 {
-    MergeJoinBy {
+    MergeBy {
         left: put_back(left.into_iter().fuse()),
         right: put_back(right.into_iter().fuse()),
-        cmp_fn,
+        cmp_fn: MergeFuncLR(cmp_fn, PhantomData),
     }
 }
 
 /// An iterator adaptor that merge-joins items from the two base iterators in ascending order.
 ///
 /// See [`.merge_join_by()`](crate::Itertools::merge_join_by) for more information.
-#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
-pub struct MergeJoinBy<I: Iterator, J: Iterator, F> {
-    left: PutBack<Fuse<I>>,
-    right: PutBack<Fuse<J>>,
-    cmp_fn: F,
+pub type MergeJoinBy<I, J, F> =
+    MergeBy<I, J, MergeFuncLR<F, <F as FuncLR<<I as Iterator>::Item, <J as Iterator>::Item>>::T>>;
+
+#[derive(Clone, Debug)]
+pub struct MergeFuncLR<F, T>(F, PhantomData<T>);
+
+pub trait FuncLR<L, R> {
+    type T;
+}
+
+impl<L, R, T, F: FnMut(&L, &R) -> T> FuncLR<L, R> for F {
+    type T = T;
 }
 
 pub trait OrderingOrBool<L, R> {
@@ -44,11 +115,11 @@ pub trait OrderingOrBool<L, R> {
     // "merge" never returns (Some(...), Some(...), ...) so Option<Either<I::Item, J::Item>>
     // is appealing but it is always followed by two put_backs, so we think the compiler is
     // smart enough to optimize it. Or we could move put_backs into "merge".
-    fn merge(self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult);
+    fn merge(&mut self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult);
     fn size_hint(left: SizeHint, right: SizeHint) -> SizeHint;
 }
 
-impl<L, R> OrderingOrBool<L, R> for Ordering {
+impl<L, R, F: FnMut(&L, &R) -> Ordering> OrderingOrBool<L, R> for MergeFuncLR<F, Ordering> {
     type MergeResult = EitherOrBoth<L, R>;
     fn left(left: L) -> Self::MergeResult {
         EitherOrBoth::Left(left)
@@ -56,8 +127,8 @@ impl<L, R> OrderingOrBool<L, R> for Ordering {
     fn right(right: R) -> Self::MergeResult {
         EitherOrBoth::Right(right)
     }
-    fn merge(self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult) {
-        match self {
+    fn merge(&mut self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult) {
+        match self.0(&left, &right) {
             Ordering::Equal => (None, None, EitherOrBoth::Both(left, right)),
             Ordering::Less => (None, Some(right), EitherOrBoth::Left(left)),
             Ordering::Greater => (Some(left), None, EitherOrBoth::Right(right)),
@@ -75,7 +146,7 @@ impl<L, R> OrderingOrBool<L, R> for Ordering {
     }
 }
 
-impl<L, R> OrderingOrBool<L, R> for bool {
+impl<L, R, F: FnMut(&L, &R) -> bool> OrderingOrBool<L, R> for MergeFuncLR<F, bool> {
     type MergeResult = Either<L, R>;
     fn left(left: L) -> Self::MergeResult {
         Either::Left(left)
@@ -83,8 +154,8 @@ impl<L, R> OrderingOrBool<L, R> for bool {
     fn right(right: R) -> Self::MergeResult {
         Either::Right(right)
     }
-    fn merge(self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult) {
-        if self {
+    fn merge(&mut self, left: L, right: R) -> (Option<L>, Option<R>, Self::MergeResult) {
+        if self.0(&left, &right) {
             (None, Some(right), Either::Left(left))
         } else {
             (Some(left), None, Either::Right(right))
@@ -96,40 +167,84 @@ impl<L, R> OrderingOrBool<L, R> for bool {
     }
 }
 
-impl<I, J, F> Clone for MergeJoinBy<I, J, F>
-    where I: Iterator,
-          J: Iterator,
-          PutBack<Fuse<I>>: Clone,
-          PutBack<Fuse<J>>: Clone,
-          F: Clone,
+impl<T, F: FnMut(&T, &T) -> bool> OrderingOrBool<T, T> for F {
+    type MergeResult = T;
+    fn left(left: T) -> Self::MergeResult {
+        left
+    }
+    fn right(right: T) -> Self::MergeResult {
+        right
+    }
+    fn merge(&mut self, left: T, right: T) -> (Option<T>, Option<T>, Self::MergeResult) {
+        if self(&left, &right) {
+            (None, Some(right), left)
+        } else {
+            (Some(left), None, right)
+        }
+    }
+    fn size_hint(left: SizeHint, right: SizeHint) -> SizeHint {
+        // Not ExactSizeIterator because size may be larger than usize
+        size_hint::add(left, right)
+    }
+}
+
+impl<T: PartialOrd> OrderingOrBool<T, T> for MergeLte {
+    type MergeResult = T;
+    fn left(left: T) -> Self::MergeResult {
+        left
+    }
+    fn right(right: T) -> Self::MergeResult {
+        right
+    }
+    fn merge(&mut self, left: T, right: T) -> (Option<T>, Option<T>, Self::MergeResult) {
+        if left <= right {
+            (None, Some(right), left)
+        } else {
+            (Some(left), None, right)
+        }
+    }
+    fn size_hint(left: SizeHint, right: SizeHint) -> SizeHint {
+        // Not ExactSizeIterator because size may be larger than usize
+        size_hint::add(left, right)
+    }
+}
+
+impl<I, J, F> Clone for MergeBy<I, J, F>
+where
+    I: Iterator,
+    J: Iterator,
+    PutBack<Fuse<I>>: Clone,
+    PutBack<Fuse<J>>: Clone,
+    F: Clone,
 {
     clone_fields!(left, right, cmp_fn);
 }
 
-impl<I, J, F> fmt::Debug for MergeJoinBy<I, J, F>
-    where I: Iterator + fmt::Debug,
-          I::Item: fmt::Debug,
-          J: Iterator + fmt::Debug,
-          J::Item: fmt::Debug,
+impl<I, J, F> fmt::Debug for MergeBy<I, J, F>
+where
+    I: Iterator + fmt::Debug,
+    I::Item: fmt::Debug,
+    J: Iterator + fmt::Debug,
+    J::Item: fmt::Debug,
 {
-    debug_fmt_fields!(MergeJoinBy, left, right);
+    debug_fmt_fields!(MergeBy, left, right);
 }
 
-impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
-    where I: Iterator,
-          J: Iterator,
-          F: FnMut(&I::Item, &J::Item) -> T,
-          T: OrderingOrBool<I::Item, J::Item>,
+impl<I, J, F> Iterator for MergeBy<I, J, F>
+where
+    I: Iterator,
+    J: Iterator,
+    F: OrderingOrBool<I::Item, J::Item>,
 {
-    type Item = T::MergeResult;
+    type Item = F::MergeResult;
 
     fn next(&mut self) -> Option<Self::Item> {
         match (self.left.next(), self.right.next()) {
             (None, None) => None,
-            (Some(left), None) => Some(T::left(left)),
-            (None, Some(right)) => Some(T::right(right)),
+            (Some(left), None) => Some(F::left(left)),
+            (None, Some(right)) => Some(F::right(right)),
             (Some(left), Some(right)) => {
-                let (left, right, next) = (self.cmp_fn)(&left, &right).merge(left, right);
+                let (left, right, next) = self.cmp_fn.merge(left, right);
                 if let Some(left) = left {
                     self.left.put_back(left);
                 }
@@ -142,7 +257,7 @@ impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
     }
 
     fn size_hint(&self) -> SizeHint {
-        T::size_hint(self.left.size_hint(), self.right.size_hint())
+        F::size_hint(self.left.size_hint(), self.right.size_hint())
     }
 
     fn count(mut self) -> usize {
@@ -154,7 +269,7 @@ impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
                 (None, Some(_right)) => break count + 1 + self.right.into_parts().1.count(),
                 (Some(left), Some(right)) => {
                     count += 1;
-                    let (left, right, _) = (self.cmp_fn)(&left, &right).merge(left, right);
+                    let (left, right, _) = self.cmp_fn.merge(left, right);
                     if let Some(left) = left {
                         self.left.put_back(left);
                     }
@@ -172,17 +287,13 @@ impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
             match (self.left.next(), self.right.next()) {
                 (None, None) => break previous_element,
                 (Some(left), None) => {
-                    break Some(T::left(
-                        self.left.into_parts().1.last().unwrap_or(left),
-                    ))
+                    break Some(F::left(self.left.into_parts().1.last().unwrap_or(left)))
                 }
                 (None, Some(right)) => {
-                    break Some(T::right(
-                        self.right.into_parts().1.last().unwrap_or(right),
-                    ))
+                    break Some(F::right(self.right.into_parts().1.last().unwrap_or(right)))
                 }
                 (Some(left), Some(right)) => {
-                    let (left, right, elem) = (self.cmp_fn)(&left, &right).merge(left, right);
+                    let (left, right, elem) = self.cmp_fn.merge(left, right);
                     if let Some(left) = left {
                         self.left.put_back(left);
                     }
@@ -203,10 +314,10 @@ impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
             n -= 1;
             match (self.left.next(), self.right.next()) {
                 (None, None) => break None,
-                (Some(_left), None) => break self.left.nth(n).map(T::left),
-                (None, Some(_right)) => break self.right.nth(n).map(T::right),
+                (Some(_left), None) => break self.left.nth(n).map(F::left),
+                (None, Some(_right)) => break self.right.nth(n).map(F::right),
                 (Some(left), Some(right)) => {
-                    let (left, right, _) = (self.cmp_fn)(&left, &right).merge(left, right);
+                    let (left, right, _) = self.cmp_fn.merge(left, right);
                     if let Some(left) = left {
                         self.left.put_back(left);
                     }
@@ -218,3 +329,11 @@ impl<I, J, F, T> Iterator for MergeJoinBy<I, J, F>
         }
     }
 }
+
+impl<I, J, F> FusedIterator for MergeBy<I, J, F>
+where
+    I: Iterator,
+    J: Iterator,
+    F: OrderingOrBool<I::Item, J::Item>,
+{
+}