(function() {var type_impls = { "itertools":[["
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impl<I: Clone> Clone for GroupingMap<I>

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fn clone(&self) -> GroupingMap<I>

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
","Clone","itertools::grouping_map::GroupingMapBy"],["
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impl<I: Debug> Debug for GroupingMap<I>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
","Debug","itertools::grouping_map::GroupingMapBy"],["
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impl<I, K, V> GroupingMap<I>
where\n I: Iterator<Item = (K, V)>,\n K: Hash + Eq,

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pub fn aggregate<FO, R>(self, operation: FO) -> HashMap<K, R>
where\n FO: FnMut(Option<R>, &K, V) -> Option<R>,

This is the generic way to perform any operation on a GroupingMap.\nIt’s suggested to use this method only to implement custom operations\nwhen the already provided ones are not enough.

\n

Groups elements from the GroupingMap source by key and applies operation to the elements\nof each group sequentially, passing the previously accumulated value, a reference to the key\nand the current element as arguments, and stores the results in an HashMap.

\n

The operation function is invoked on each element with the following parameters:

\n
    \n
  • the current value of the accumulator of the group if there is currently one;
    • \n
  • a reference to the key of the group this element belongs to;
    • \n
  • the element from the source being aggregated;
    • \n
\n

If operation returns Some(element) then the accumulator is updated with element,\notherwise the previous accumulation is discarded.

\n

Return a HashMap associating the key of each group with the result of aggregation of\nthat group’s elements. If the aggregation of the last element of a group discards the\naccumulator then there won’t be an entry associated to that group’s key.

\n\n
use itertools::Itertools;\n\nlet data = vec![2, 8, 5, 7, 9, 0, 4, 10];\nlet lookup = data.into_iter()\n    .into_grouping_map_by(|&n| n % 4)\n    .aggregate(|acc, _key, val| {\n        if val == 0 || val == 10 {\n            None\n        } else {\n            Some(acc.unwrap_or(0) + val)\n        }\n    });\n\nassert_eq!(lookup[&0], 4);        // 0 resets the accumulator so only 4 is summed\nassert_eq!(lookup[&1], 5 + 9);\nassert_eq!(lookup.get(&2), None); // 10 resets the accumulator and nothing is summed afterward\nassert_eq!(lookup[&3], 7);\nassert_eq!(lookup.len(), 3);      // The final keys are only 0, 1 and 2
\n
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pub fn fold_with<FI, FO, R>(self, init: FI, operation: FO) -> HashMap<K, R>
where\n FI: FnMut(&K, &V) -> R,\n FO: FnMut(R, &K, V) -> R,

Groups elements from the GroupingMap source by key and applies operation to the elements\nof each group sequentially, passing the previously accumulated value, a reference to the key\nand the current element as arguments, and stores the results in a new map.

\n

init is called to obtain the initial value of each accumulator.

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operation is a function that is invoked on each element with the following parameters:

\n
    \n
  • the current value of the accumulator of the group;
    • \n
  • a reference to the key of the group this element belongs to;
    • \n
  • the element from the source being accumulated.
    • \n
\n

Return a HashMap associating the key of each group with the result of folding that group’s elements.

\n\n
use itertools::Itertools;\n\n#[derive(Debug, Default)]\nstruct Accumulator {\n  acc: usize,\n}\n\nlet lookup = (1..=7)\n    .into_grouping_map_by(|&n| n % 3)\n    .fold_with(|_key, _val| Default::default(), |Accumulator { acc }, _key, val| {\n        let acc = acc + val;\n        Accumulator { acc }\n     });\n\nassert_eq!(lookup[&0].acc, 3 + 6);\nassert_eq!(lookup[&1].acc, 1 + 4 + 7);\nassert_eq!(lookup[&2].acc, 2 + 5);\nassert_eq!(lookup.len(), 3);
\n
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pub fn fold<FO, R>(self, init: R, operation: FO) -> HashMap<K, R>
where\n R: Clone,\n FO: FnMut(R, &K, V) -> R,

Groups elements from the GroupingMap source by key and applies operation to the elements\nof each group sequentially, passing the previously accumulated value, a reference to the key\nand the current element as arguments, and stores the results in a new map.

\n

init is the value from which will be cloned the initial value of each accumulator.

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operation is a function that is invoked on each element with the following parameters:

\n
    \n
  • the current value of the accumulator of the group;
    • \n
  • a reference to the key of the group this element belongs to;
    • \n
  • the element from the source being accumulated.
    • \n
\n

Return a HashMap associating the key of each group with the result of folding that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = (1..=7)\n    .into_grouping_map_by(|&n| n % 3)\n    .fold(0, |acc, _key, val| acc + val);\n\nassert_eq!(lookup[&0], 3 + 6);\nassert_eq!(lookup[&1], 1 + 4 + 7);\nassert_eq!(lookup[&2], 2 + 5);\nassert_eq!(lookup.len(), 3);
\n
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pub fn fold_first<FO>(self, operation: FO) -> HashMap<K, V>
where\n FO: FnMut(V, &K, V) -> V,

Groups elements from the GroupingMap source by key and applies operation to the elements\nof each group sequentially, passing the previously accumulated value, a reference to the key\nand the current element as arguments, and stores the results in a new map.

\n

This is similar to fold but the initial value of the accumulator is the first element of the group.

\n

operation is a function that is invoked on each element with the following parameters:

\n
    \n
  • the current value of the accumulator of the group;
    • \n
  • a reference to the key of the group this element belongs to;
    • \n
  • the element from the source being accumulated.
    • \n
\n

Return a HashMap associating the key of each group with the result of folding that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = (1..=7)\n    .into_grouping_map_by(|&n| n % 3)\n    .fold_first(|acc, _key, val| acc + val);\n\nassert_eq!(lookup[&0], 3 + 6);\nassert_eq!(lookup[&1], 1 + 4 + 7);\nassert_eq!(lookup[&2], 2 + 5);\nassert_eq!(lookup.len(), 3);
\n
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pub fn collect<C>(self) -> HashMap<K, C>
where\n C: Default + Extend<V>,

Groups elements from the GroupingMap source by key and collects the elements of each group in\nan instance of C. The iteration order is preserved when inserting elements.

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Return a HashMap associating the key of each group with the collection containing that group’s elements.

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use itertools::Itertools;\nuse std::collections::HashSet;\n\nlet lookup = vec![0, 1, 2, 3, 4, 5, 6, 2, 3, 6].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .collect::<HashSet<_>>();\n\nassert_eq!(lookup[&0], vec![0, 3, 6].into_iter().collect::<HashSet<_>>());\nassert_eq!(lookup[&1], vec![1, 4].into_iter().collect::<HashSet<_>>());\nassert_eq!(lookup[&2], vec![2, 5].into_iter().collect::<HashSet<_>>());\nassert_eq!(lookup.len(), 3);
\n
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pub fn max(self) -> HashMap<K, V>
where\n V: Ord,

Groups elements from the GroupingMap source by key and finds the maximum of each group.

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If several elements are equally maximum, the last element is picked.

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Returns a HashMap associating the key of each group with the maximum of that group’s elements.

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use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .max();\n\nassert_eq!(lookup[&0], 12);\nassert_eq!(lookup[&1], 7);\nassert_eq!(lookup[&2], 8);\nassert_eq!(lookup.len(), 3);
\n
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pub fn max_by<F>(self, compare: F) -> HashMap<K, V>
where\n F: FnMut(&K, &V, &V) -> Ordering,

Groups elements from the GroupingMap source by key and finds the maximum of each group\nwith respect to the specified comparison function.

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If several elements are equally maximum, the last element is picked.

\n

Returns a HashMap associating the key of each group with the maximum of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .max_by(|_key, x, y| y.cmp(x));\n\nassert_eq!(lookup[&0], 3);\nassert_eq!(lookup[&1], 1);\nassert_eq!(lookup[&2], 5);\nassert_eq!(lookup.len(), 3);
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pub fn max_by_key<F, CK>(self, f: F) -> HashMap<K, V>
where\n F: FnMut(&K, &V) -> CK,\n CK: Ord,

Groups elements from the GroupingMap source by key and finds the element of each group\nthat gives the maximum from the specified function.

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If several elements are equally maximum, the last element is picked.

\n

Returns a HashMap associating the key of each group with the maximum of that group’s elements.

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use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .max_by_key(|_key, &val| val % 4);\n\nassert_eq!(lookup[&0], 3);\nassert_eq!(lookup[&1], 7);\nassert_eq!(lookup[&2], 5);\nassert_eq!(lookup.len(), 3);
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pub fn min(self) -> HashMap<K, V>
where\n V: Ord,

Groups elements from the GroupingMap source by key and finds the minimum of each group.

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If several elements are equally minimum, the first element is picked.

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Returns a HashMap associating the key of each group with the minimum of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .min();\n\nassert_eq!(lookup[&0], 3);\nassert_eq!(lookup[&1], 1);\nassert_eq!(lookup[&2], 5);\nassert_eq!(lookup.len(), 3);
\n
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pub fn min_by<F>(self, compare: F) -> HashMap<K, V>
where\n F: FnMut(&K, &V, &V) -> Ordering,

Groups elements from the GroupingMap source by key and finds the minimum of each group\nwith respect to the specified comparison function.

\n

If several elements are equally minimum, the first element is picked.

\n

Returns a HashMap associating the key of each group with the minimum of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .min_by(|_key, x, y| y.cmp(x));\n\nassert_eq!(lookup[&0], 12);\nassert_eq!(lookup[&1], 7);\nassert_eq!(lookup[&2], 8);\nassert_eq!(lookup.len(), 3);
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pub fn min_by_key<F, CK>(self, f: F) -> HashMap<K, V>
where\n F: FnMut(&K, &V) -> CK,\n CK: Ord,

Groups elements from the GroupingMap source by key and finds the element of each group\nthat gives the minimum from the specified function.

\n

If several elements are equally minimum, the first element is picked.

\n

Returns a HashMap associating the key of each group with the minimum of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .min_by_key(|_key, &val| val % 4);\n\nassert_eq!(lookup[&0], 12);\nassert_eq!(lookup[&1], 4);\nassert_eq!(lookup[&2], 8);\nassert_eq!(lookup.len(), 3);
\n
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pub fn minmax(self) -> HashMap<K, MinMaxResult<V>>
where\n V: Ord,

Groups elements from the GroupingMap source by key and find the maximum and minimum of\neach group.

\n

If several elements are equally maximum, the last element is picked.\nIf several elements are equally minimum, the first element is picked.

\n

See .minmax() for the non-grouping version.

\n

Differences from the non grouping version:

\n
    \n
  • It never produces a MinMaxResult::NoElements
    • \n
  • It doesn’t have any speedup
    • \n
\n

Returns a HashMap associating the key of each group with the minimum and maximum of that group’s elements.

\n\n
use itertools::Itertools;\nuse itertools::MinMaxResult::{OneElement, MinMax};\n\nlet lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .minmax();\n\nassert_eq!(lookup[&0], MinMax(3, 12));\nassert_eq!(lookup[&1], MinMax(1, 7));\nassert_eq!(lookup[&2], OneElement(5));\nassert_eq!(lookup.len(), 3);
\n
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pub fn minmax_by<F>(self, compare: F) -> HashMap<K, MinMaxResult<V>>
where\n F: FnMut(&K, &V, &V) -> Ordering,

Groups elements from the GroupingMap source by key and find the maximum and minimum of\neach group with respect to the specified comparison function.

\n

If several elements are equally maximum, the last element is picked.\nIf several elements are equally minimum, the first element is picked.

\n

It has the same differences from the non-grouping version as minmax.

\n

Returns a HashMap associating the key of each group with the minimum and maximum of that group’s elements.

\n\n
use itertools::Itertools;\nuse itertools::MinMaxResult::{OneElement, MinMax};\n\nlet lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .minmax_by(|_key, x, y| y.cmp(x));\n\nassert_eq!(lookup[&0], MinMax(12, 3));\nassert_eq!(lookup[&1], MinMax(7, 1));\nassert_eq!(lookup[&2], OneElement(5));\nassert_eq!(lookup.len(), 3);
\n
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pub fn minmax_by_key<F, CK>(self, f: F) -> HashMap<K, MinMaxResult<V>>
where\n F: FnMut(&K, &V) -> CK,\n CK: Ord,

Groups elements from the GroupingMap source by key and find the elements of each group\nthat gives the minimum and maximum from the specified function.

\n

If several elements are equally maximum, the last element is picked.\nIf several elements are equally minimum, the first element is picked.

\n

It has the same differences from the non-grouping version as minmax.

\n

Returns a HashMap associating the key of each group with the minimum and maximum of that group’s elements.

\n\n
use itertools::Itertools;\nuse itertools::MinMaxResult::{OneElement, MinMax};\n\nlet lookup = vec![1, 3, 4, 5, 7, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .minmax_by_key(|_key, &val| val % 4);\n\nassert_eq!(lookup[&0], MinMax(12, 3));\nassert_eq!(lookup[&1], MinMax(4, 7));\nassert_eq!(lookup[&2], OneElement(5));\nassert_eq!(lookup.len(), 3);
\n
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pub fn sum(self) -> HashMap<K, V>
where\n V: Add<V, Output = V>,

Groups elements from the GroupingMap source by key and sums them.

\n

This is just a shorthand for self.fold_first(|acc, _, val| acc + val).\nIt is more limited than Iterator::sum since it doesn’t use the Sum trait.

\n

Returns a HashMap associating the key of each group with the sum of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .sum();\n\nassert_eq!(lookup[&0], 3 + 9 + 12);\nassert_eq!(lookup[&1], 1 + 4 + 7);\nassert_eq!(lookup[&2], 5 + 8);\nassert_eq!(lookup.len(), 3);
\n
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pub fn product(self) -> HashMap<K, V>
where\n V: Mul<V, Output = V>,

Groups elements from the GroupingMap source by key and multiply them.

\n

This is just a shorthand for self.fold_first(|acc, _, val| acc * val).\nIt is more limited than Iterator::product since it doesn’t use the Product trait.

\n

Returns a HashMap associating the key of each group with the product of that group’s elements.

\n\n
use itertools::Itertools;\n\nlet lookup = vec![1, 3, 4, 5, 7, 8, 9, 12].into_iter()\n    .into_grouping_map_by(|&n| n % 3)\n    .product();\n\nassert_eq!(lookup[&0], 3 * 9 * 12);\nassert_eq!(lookup[&1], 1 * 4 * 7);\nassert_eq!(lookup[&2], 5 * 8);\nassert_eq!(lookup.len(), 3);
\n
",0,"itertools::grouping_map::GroupingMapBy"]] };if (window.register_type_impls) {window.register_type_impls(type_impls);} else {window.pending_type_impls = type_impls;}})()