Upgrade itertools to 0.10.5
This project was upgraded with external_updater.
Usage: tools/external_updater/updater.sh update rust/crates/itertools
For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md
Test: TreeHugger
Change-Id: I04ecd1d5827d6d1822997f324e6bac8e8bd8ea83
diff --git a/src/extrema_set.rs b/src/extrema_set.rs
new file mode 100644
index 0000000..ae12836
--- /dev/null
+++ b/src/extrema_set.rs
@@ -0,0 +1,48 @@
+use std::cmp::Ordering;
+
+/// Implementation guts for `min_set`, `min_set_by`, and `min_set_by_key`.
+pub fn min_set_impl<I, K, F, Compare>(
+ mut it: I,
+ mut key_for: F,
+ mut compare: Compare,
+) -> Vec<I::Item>
+where
+ I: Iterator,
+ F: FnMut(&I::Item) -> K,
+ Compare: FnMut(&I::Item, &I::Item, &K, &K) -> Ordering,
+{
+ match it.next() {
+ None => Vec::new(),
+ Some(element) => {
+ let mut current_key = key_for(&element);
+ let mut result = vec![element];
+ it.for_each(|element| {
+ let key = key_for(&element);
+ match compare(&element, &result[0], &key, ¤t_key) {
+ Ordering::Less => {
+ result.clear();
+ result.push(element);
+ current_key = key;
+ }
+ Ordering::Equal => {
+ result.push(element);
+ }
+ Ordering::Greater => {}
+ }
+ });
+ result
+ }
+ }
+}
+
+/// Implementation guts for `ax_set`, `max_set_by`, and `max_set_by_key`.
+pub fn max_set_impl<I, K, F, Compare>(it: I, key_for: F, mut compare: Compare) -> Vec<I::Item>
+where
+ I: Iterator,
+ F: FnMut(&I::Item) -> K,
+ Compare: FnMut(&I::Item, &I::Item, &K, &K) -> Ordering,
+{
+ min_set_impl(it, key_for, |it1, it2, key1, key2| {
+ compare(it2, it1, key2, key1)
+ })
+}
