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Added fold method to solution of iterators5

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This commit is contained in:
vallops99 2025-06-13 20:03:10 +02:00
parent cb60c8887c
commit b72d3d37d4
1 changed files with 14 additions and 0 deletions
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14
solutions/18_iterators/iterators5.rs
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@ -64,6 +64,17 @@ fn count_collection_iterator_flat(
.count() .count()
} }
// Equivalent to `count_collection_iterator`, `count_collection_iterator_flat` and `count_iterator`
// iterating over the collection with an accumulator in order to avoid the sum step after.
fn count_collection_iterator_fold(
collection: &[HashMap<String, Progress>],
value: Progress,
) -> usize {
collection
.iter()
.fold(0, |acc, map| acc + count_iterator(map, value))
}
fn main() { fn main() {
// You can optionally experiment here. // You can optionally experiment here.
} }
@ -133,6 +144,7 @@ mod tests {
let collection = get_vec_map(); let collection = get_vec_map();
assert_eq!(count_collection_iterator(&collection, Complete), 6); assert_eq!(count_collection_iterator(&collection, Complete), 6);
assert_eq!(count_collection_iterator_flat(&collection, Complete), 6); assert_eq!(count_collection_iterator_flat(&collection, Complete), 6);
assert_eq!(count_collection_iterator_fold(&collection, Complete), 6);
} }
#[test] #[test]
@ -140,6 +152,7 @@ mod tests {
let collection = get_vec_map(); let collection = get_vec_map();
assert_eq!(count_collection_iterator(&collection, Some), 1); assert_eq!(count_collection_iterator(&collection, Some), 1);
assert_eq!(count_collection_iterator_flat(&collection, Some), 1); assert_eq!(count_collection_iterator_flat(&collection, Some), 1);
assert_eq!(count_collection_iterator_fold(&collection, Some), 1);
} }
#[test] #[test]
@ -147,6 +160,7 @@ mod tests {
let collection = get_vec_map(); let collection = get_vec_map();
assert_eq!(count_collection_iterator(&collection, None), 4); assert_eq!(count_collection_iterator(&collection, None), 4);
assert_eq!(count_collection_iterator_flat(&collection, None), 4); assert_eq!(count_collection_iterator_flat(&collection, None), 4);
assert_eq!(count_collection_iterator_fold(&collection, None), 4);
} }
#[test] #[test]