Merging upstream version 1.75.0+dfsg1.

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

1 files changed, 535 insertions, 0 deletions

diff --git a/vendor/itertools-0.10.5/src/grouping_map.rs b/vendor/itertools-0.10.5/src/grouping_map.rs
new file mode 100644
index 000000000..bb5b582c9
--- /dev/null
+++ b/vendor/itertools-0.10.5/src/grouping_map.rs
@@ -0,0 +1,535 @@
+#![cfg(feature = "use_std")]
+
+use crate::MinMaxResult;
+use std::collections::HashMap;
+use std::cmp::Ordering;
+use std::hash::Hash;
+use std::iter::Iterator;
+use std::ops::{Add, Mul};
+
+/// A wrapper to allow for an easy [`into_grouping_map_by`](crate::Itertools::into_grouping_map_by)
+#[derive(Clone, Debug)]
+pub struct MapForGrouping<I, F>(I, F);
+
+impl<I, F> MapForGrouping<I, F> {
+    pub(crate) fn new(iter: I, key_mapper: F) -> Self {
+        Self(iter, key_mapper)
+    }
+}
+
+impl<K, V, I, F> Iterator for MapForGrouping<I, F>
+    where I: Iterator<Item = V>,
+          K: Hash + Eq,
+          F: FnMut(&V) -> K,
+{
+    type Item = (K, V);
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next().map(|val| ((self.1)(&val), val))
+    }
+}
+
+/// Creates a new `GroupingMap` from `iter`
+pub fn new<I, K, V>(iter: I) -> GroupingMap<I>
+    where I: Iterator<Item = (K, V)>,
+          K: Hash + Eq,
+{
+    GroupingMap { iter }
+}
+
+/// `GroupingMapBy` is an intermediate struct for efficient group-and-fold operations.
+/// 
+/// See [`GroupingMap`] for more informations.
+pub type GroupingMapBy<I, F> = GroupingMap<MapForGrouping<I, F>>;
+
+/// `GroupingMap` is an intermediate struct for efficient group-and-fold operations.
+/// It groups elements by their key and at the same time fold each group
+/// using some aggregating operation.
+/// 
+/// No method on this struct performs temporary allocations.
+#[derive(Clone, Debug)]
+#[must_use = "GroupingMap is lazy and do nothing unless consumed"]
+pub struct GroupingMap<I> {
+    iter: I,
+}
+
+impl<I, K, V> GroupingMap<I>
+    where I: Iterator<Item = (K, V)>,
+          K: Hash + Eq,
+{
+    /// This is the generic way to perform any operation on a `GroupingMap`.
+    /// It's suggested to use this method only to implement custom operations
+    /// when the already provided ones are not enough.
+    /// 
+    /// Groups elements from the `GroupingMap` source by key and applies `operation` to the elements
+    /// of each group sequentially, passing the previously accumulated value, a reference to the key
+    /// and the current element as arguments, and stores the results in an `HashMap`.
+    ///
+    /// The `operation` function is invoked on each element with the following parameters:
+    ///  - the current value of the accumulator of the group if there is currently one;
+    ///  - a reference to the key of the group this element belongs to;
+    ///  - the element from the source being aggregated;
+    /// 
+    /// If `operation` returns `Some(element)` then the accumulator is updated with `element`,
+    /// otherwise the previous accumulation is discarded.
+    ///
+    /// Return a `HashMap` associating the key of each group with the result of aggregation of
+    /// that group's elements. If the aggregation of the last element of a group discards the
+    /// accumulator then there won't be an entry associated to that group's key.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let data = vec![2, 8, 5, 7, 9, 0, 4, 10];
+    /// let lookup = data.into_iter()
+    ///     .into_grouping_map_by(|&n| n % 4)
+    ///     .aggregate(|acc, _key, val| {
+    ///         if val == 0 || val == 10 {
+    ///             None
+    ///         } else {
+    ///             Some(acc.unwrap_or(0) + val)
+    ///         }
+    ///     });
+    /// 
+    /// assert_eq!(lookup[&0], 4);        // 0 resets the accumulator so only 4 is summed
+    /// assert_eq!(lookup[&1], 5 + 9);
+    /// assert_eq!(lookup.get(&2), None); // 10 resets the accumulator and nothing is summed afterward
+    /// assert_eq!(lookup[&3], 7);
+    /// assert_eq!(lookup.len(), 3);      // The final keys are only 0, 1 and 2
+    /// ```
+    pub fn aggregate<FO, R>(self, mut operation: FO) -> HashMap<K, R>
+        where FO: FnMut(Option<R>, &K, V) -> Option<R>,
+    {
+        let mut destination_map = HashMap::new();
+
+        self.iter.for_each(|(key, val)| {
+            let acc = destination_map.remove(&key);
+            if let Some(op_res) = operation(acc, &key, val) {
+                destination_map.insert(key, op_res);
+            }
+        });
+
+        destination_map
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and applies `operation` to the elements
+    /// of each group sequentially, passing the previously accumulated value, a reference to the key
+    /// and the current element as arguments, and stores the results in a new map.
+    ///
+    /// `init` is the value from which will be cloned the initial value of each accumulator.
+    ///
+    /// `operation` is a function that is invoked on each element with the following parameters:
+    ///  - the current value of the accumulator of the group;
+    ///  - a reference to the key of the group this element belongs to;
+    ///  - the element from the source being accumulated.
+    ///
+    /// Return a `HashMap` associating the key of each group with the result of folding that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = (1..=7)
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .fold(0, |acc, _key, val| acc + val);
+    /// 
+    /// assert_eq!(lookup[&0], 3 + 6);
+    /// assert_eq!(lookup[&1], 1 + 4 + 7);
+    /// assert_eq!(lookup[&2], 2 + 5);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn fold<FO, R>(self, init: R, mut operation: FO) -> HashMap<K, R>
+        where R: Clone,
+              FO: FnMut(R, &K, V) -> R,
+    {
+        self.aggregate(|acc, key, val| {
+            let acc = acc.unwrap_or_else(|| init.clone());
+            Some(operation(acc, key, val))
+        })
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and applies `operation` to the elements
+    /// of each group sequentially, passing the previously accumulated value, a reference to the key
+    /// and the current element as arguments, and stores the results in a new map.
+    ///
+    /// This is similar to [`fold`] but the initial value of the accumulator is the first element of the group.
+    ///
+    /// `operation` is a function that is invoked on each element with the following parameters:
+    ///  - the current value of the accumulator of the group;
+    ///  - a reference to the key of the group this element belongs to;
+    ///  - the element from the source being accumulated.
+    ///
+    /// Return a `HashMap` associating the key of each group with the result of folding that group's elements.
+    /// 
+    /// [`fold`]: GroupingMap::fold
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = (1..=7)
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .fold_first(|acc, _key, val| acc + val);
+    /// 
+    /// assert_eq!(lookup[&0], 3 + 6);
+    /// assert_eq!(lookup[&1], 1 + 4 + 7);
+    /// assert_eq!(lookup[&2], 2 + 5);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn fold_first<FO>(self, mut operation: FO) -> HashMap<K, V>
+        where FO: FnMut(V, &K, V) -> V,
+    {
+        self.aggregate(|acc, key, val| {
+            Some(match acc {
+                Some(acc) => operation(acc, key, val),
+                None => val,
+            })
+        })
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and collects the elements of each group in
+    /// an instance of `C`. The iteration order is preserved when inserting elements. 
+    /// 
+    /// Return a `HashMap` associating the key of each group with the collection containing that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// use std::collections::HashSet;
+    /// 
+    /// let lookup = vec![0, 1, 2, 3, 4, 5, 6, 2, 3, 6].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .collect::<HashSet<_>>();
+    /// 
+    /// assert_eq!(lookup[&0], vec![0, 3, 6].into_iter().collect::<HashSet<_>>());
+    /// assert_eq!(lookup[&1], vec![1, 4].into_iter().collect::<HashSet<_>>());
+    /// assert_eq!(lookup[&2], vec![2, 5].into_iter().collect::<HashSet<_>>());
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn collect<C>(self) -> HashMap<K, C>
+        where C: Default + Extend<V>,
+    {
+        let mut destination_map = HashMap::new();
+
+        self.iter.for_each(|(key, val)| {
+            destination_map.entry(key).or_insert_with(C::default).extend(Some(val));
+        });
+
+        destination_map
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the maximum of each group.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .max();
+    /// 
+    /// assert_eq!(lookup[&0], 12);
+    /// assert_eq!(lookup[&1], 7);
+    /// assert_eq!(lookup[&2], 8);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn max(self) -> HashMap<K, V>
+        where V: Ord,
+    {
+        self.max_by(|_, v1, v2| V::cmp(v1, v2))
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the maximum of each group
+    /// with respect to the specified comparison function.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .max_by(|_key, x, y| y.cmp(x));
+    /// 
+    /// assert_eq!(lookup[&0], 3);
+    /// assert_eq!(lookup[&1], 1);
+    /// assert_eq!(lookup[&2], 5);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn max_by<F>(self, mut compare: F) -> HashMap<K, V>
+        where F: FnMut(&K, &V, &V) -> Ordering,
+    {
+        self.fold_first(|acc, key, val| match compare(key, &acc, &val) {
+            Ordering::Less | Ordering::Equal => val,
+            Ordering::Greater => acc
+        })
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the element of each group
+    /// that gives the maximum from the specified function.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .max_by_key(|_key, &val| val % 4);
+    /// 
+    /// assert_eq!(lookup[&0], 3);
+    /// assert_eq!(lookup[&1], 7);
+    /// assert_eq!(lookup[&2], 5);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn max_by_key<F, CK>(self, mut f: F) -> HashMap<K, V>
+        where F: FnMut(&K, &V) -> CK,
+              CK: Ord,
+    {
+        self.max_by(|key, v1, v2| f(key, v1).cmp(&f(key, v2)))
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the minimum of each group.
+    /// 
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .min();
+    /// 
+    /// assert_eq!(lookup[&0], 3);
+    /// assert_eq!(lookup[&1], 1);
+    /// assert_eq!(lookup[&2], 5);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn min(self) -> HashMap<K, V>
+        where V: Ord,
+    {
+        self.min_by(|_, v1, v2| V::cmp(v1, v2))
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the minimum of each group
+    /// with respect to the specified comparison function.
+    /// 
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .min_by(|_key, x, y| y.cmp(x));
+    /// 
+    /// assert_eq!(lookup[&0], 12);
+    /// assert_eq!(lookup[&1], 7);
+    /// assert_eq!(lookup[&2], 8);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn min_by<F>(self, mut compare: F) -> HashMap<K, V>
+        where F: FnMut(&K, &V, &V) -> Ordering,
+    {
+        self.fold_first(|acc, key, val| match compare(key, &acc, &val) {
+            Ordering::Less | Ordering::Equal => acc,
+            Ordering::Greater => val
+        })
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and finds the element of each group
+    /// that gives the minimum from the specified function.
+    /// 
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .min_by_key(|_key, &val| val % 4);
+    /// 
+    /// assert_eq!(lookup[&0], 12);
+    /// assert_eq!(lookup[&1], 4);
+    /// assert_eq!(lookup[&2], 8);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn min_by_key<F, CK>(self, mut f: F) -> HashMap<K, V>
+        where F: FnMut(&K, &V) -> CK,
+              CK: Ord,
+    {
+        self.min_by(|key, v1, v2| f(key, v1).cmp(&f(key, v2)))
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and find the maximum and minimum of
+    /// each group.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// See [.minmax()](crate::Itertools::minmax) for the non-grouping version.
+    /// 
+    /// Differences from the non grouping version:
+    /// - It never produces a `MinMaxResult::NoElements`
+    /// - It doesn't have any speedup
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum and maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// use itertools::MinMaxResult::{OneElement, MinMax};
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .minmax();
+    /// 
+    /// assert_eq!(lookup[&0], MinMax(3, 12));
+    /// assert_eq!(lookup[&1], MinMax(1, 7));
+    /// assert_eq!(lookup[&2], OneElement(5));
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn minmax(self) -> HashMap<K, MinMaxResult<V>>
+        where V: Ord,
+    {
+        self.minmax_by(|_, v1, v2| V::cmp(v1, v2))
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and find the maximum and minimum of
+    /// each group with respect to the specified comparison function.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// It has the same differences from the non-grouping version as `minmax`.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum and maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// use itertools::MinMaxResult::{OneElement, MinMax};
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .minmax_by(|_key, x, y| y.cmp(x));
+    /// 
+    /// assert_eq!(lookup[&0], MinMax(12, 3));
+    /// assert_eq!(lookup[&1], MinMax(7, 1));
+    /// assert_eq!(lookup[&2], OneElement(5));
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn minmax_by<F>(self, mut compare: F) -> HashMap<K, MinMaxResult<V>>
+        where F: FnMut(&K, &V, &V) -> Ordering,
+    {
+        self.aggregate(|acc, key, val| {
+            Some(match acc {
+                Some(MinMaxResult::OneElement(e)) => {
+                    if compare(key, &val, &e) == Ordering::Less {
+                        MinMaxResult::MinMax(val, e)
+                    } else {
+                        MinMaxResult::MinMax(e, val)
+                    }
+                }
+                Some(MinMaxResult::MinMax(min, max)) => {
+                    if compare(key, &val, &min) == Ordering::Less {
+                        MinMaxResult::MinMax(val, max)
+                    } else if compare(key, &val, &max) != Ordering::Less {
+                        MinMaxResult::MinMax(min, val)
+                    } else {
+                        MinMaxResult::MinMax(min, max)
+                    }
+                }
+                None => MinMaxResult::OneElement(val),
+                Some(MinMaxResult::NoElements) => unreachable!(),
+            })
+        })
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and find the elements of each group
+    /// that gives the minimum and maximum from the specified function.
+    /// 
+    /// If several elements are equally maximum, the last element is picked.
+    /// If several elements are equally minimum, the first element is picked.
+    /// 
+    /// It has the same differences from the non-grouping version as `minmax`.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the minimum and maximum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// use itertools::MinMaxResult::{OneElement, MinMax};
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .minmax_by_key(|_key, &val| val % 4);
+    /// 
+    /// assert_eq!(lookup[&0], MinMax(12, 3));
+    /// assert_eq!(lookup[&1], MinMax(4, 7));
+    /// assert_eq!(lookup[&2], OneElement(5));
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn minmax_by_key<F, CK>(self, mut f: F) -> HashMap<K, MinMaxResult<V>>
+        where F: FnMut(&K, &V) -> CK,
+              CK: Ord,
+    {
+        self.minmax_by(|key, v1, v2| f(key, v1).cmp(&f(key, v2)))
+    }
+    
+    /// Groups elements from the `GroupingMap` source by key and sums them.
+    /// 
+    /// This is just a shorthand for `self.fold_first(|acc, _, val| acc + val)`.
+    /// It is more limited than `Iterator::sum` since it doesn't use the `Sum` trait.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the sum of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .sum();
+    /// 
+    /// assert_eq!(lookup[&0], 3 + 9 + 12);
+    /// assert_eq!(lookup[&1], 1 + 4 + 7);
+    /// assert_eq!(lookup[&2], 5 + 8);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn sum(self) -> HashMap<K, V>
+        where V: Add<V, Output = V>
+    {
+        self.fold_first(|acc, _, val| acc + val)
+    }
+
+    /// Groups elements from the `GroupingMap` source by key and multiply them.
+    /// 
+    /// This is just a shorthand for `self.fold_first(|acc, _, val| acc * val)`.
+    /// It is more limited than `Iterator::product` since it doesn't use the `Product` trait.
+    /// 
+    /// Returns a `HashMap` associating the key of each group with the product of that group's elements.
+    /// 
+    /// ```
+    /// use itertools::Itertools;
+    /// 
+    /// let lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()
+    ///     .into_grouping_map_by(|&n| n % 3)
+    ///     .product();
+    /// 
+    /// assert_eq!(lookup[&0], 3 * 9 * 12);
+    /// assert_eq!(lookup[&1], 1 * 4 * 7);
+    /// assert_eq!(lookup[&2], 5 * 8);
+    /// assert_eq!(lookup.len(), 3);
+    /// ```
+    pub fn product(self) -> HashMap<K, V>
+        where V: Mul<V, Output = V>,
+    {
+        self.fold_first(|acc, _, val| acc * val)
+    }
+}