Style tweaks and tidy up

Author: ejmount

src/k_smallest.rs

@@ -47,7 +47,7 @@ where
 
     let mut is_less_than = move |a: &_, b: &_| comparator(a, b) == Ordering::Less;
 
-    // Rearrange the into a valid heap by reordering from the second-bottom-most layer up
+    // Rearrange the into a valid heap by reordering from the second-bottom-most layer up to the root
     // Slightly faster than ordering on each insert, but only by a factor of lg(k)
     // The resulting heap has the **largest** item on top
     for i in (0..=(storage.len() / 2)).rev() {
@@ -88,13 +88,6 @@ where
     storage
 }
 
-pub(crate) fn reverse_cmp<T, F>(cmp: F) -> impl Fn(&T, &T) -> Ordering
-where
-    F: Fn(&T, &T) -> Ordering,
-{
-    move |a, b| cmp(b, a)
-}
-
 pub(crate) fn key_to_cmp<T, K, F>(key: F) -> impl Fn(&T, &T) -> Ordering
 where
     F: Fn(&T) -> K,

src/lib.rs

@@ -2956,7 +2956,7 @@ pub trait Itertools: Iterator {
         Self::Item: Ord,
     {
         // The stdlib heap has optimised handling of "holes", which is not included in our heap implementation in k_smallest_general.
-        // While the difference is unlikely to have practical impact unless `T` is very large, this method uses the stdlib structure
+        // While the difference is unlikely to have practical impact unless `Self::Item` is very large, this method uses the stdlib structure
         // to maintain performance compared to previous versions of the crate.
         use alloc::collections::BinaryHeap;
 
@@ -3011,7 +3011,7 @@ pub trait Itertools: Iterator {
     /// Sort the k largest elements into a new iterator, in descending order.
     /// Semantically equivalent to `k_smallest` with a reversed `Ord`
     /// However, this is implemented by way of a custom binary heap
-    /// which does not have the same performance characteristics for very large `T`
+    /// which does not have the same performance characteristics for very large `Self::Item`
     /// ```
     /// use itertools::Itertools;
     ///
@@ -3030,7 +3030,7 @@ pub trait Itertools: Iterator {
         Self: Sized,
         Self::Item: Ord,
     {
-        self.k_smallest_by(k, k_smallest::reverse_cmp(Self::Item::cmp))
+        self.k_largest_by(k, Self::Item::cmp)
     }
 
     /// Sort the k largest elements into a new iterator using the provided comparison.
@@ -3041,7 +3041,7 @@ pub trait Itertools: Iterator {
         Self: Sized,
         F: Fn(&Self::Item, &Self::Item) -> Ordering,
     {
-        self.k_smallest_by(k, k_smallest::reverse_cmp(cmp))
+        self.k_smallest_by(k, move |a, b| cmp(b, a))
     }
 
     /// Return the elements producing the k largest outputs of the provided function