deduplicate Index fns

src/double_priority_queue/mod.rs

@@ -34,7 +34,9 @@ pub mod iterators;
 #[cfg(not(feature = "std"))]
 use std::vec::Vec;
 
+use crate::better_to_rebuild;
 use crate::core_iterators::*;
+use crate::store::{left, level, parent, right};
 use crate::store::{Index, Position, Store};
 use crate::TryReserveError;
 use iterators::*;
@@ -1218,48 +1220,6 @@ where
     }
 }
 
-/// Compute the index of the left child of an item from its index
-#[inline(always)]
-const fn left(i: Position) -> Position {
-    Position((i.0 * 2) + 1)
-}
-/// Compute the index of the right child of an item from its index
-#[inline(always)]
-const fn right(i: Position) -> Position {
-    Position((i.0 * 2) + 2)
-}
-/// Compute the index of the parent element in the heap from its index
-#[inline(always)]
-const fn parent(i: Position) -> Position {
-    Position((i.0 - 1) / 2)
-}
-
-// Compute the level of a node from its index
-#[inline(always)]
-const fn level(i: Position) -> usize {
-    log2_fast(i.0 + 1)
-}
-
-#[inline(always)]
-const fn log2_fast(x: usize) -> usize {
-    (usize::BITS - x.leading_zeros() - 1) as usize
-}
-
-// `rebuild` takes O(len1 + len2) operations
-// and about 2 * (len1 + len2) comparisons in the worst case
-// while `extend` takes O(len2 * log_2(len1)) operations
-// and about 1 * len2 * log_2(len1) comparisons in the worst case,
-// assuming len1 >= len2.
-fn better_to_rebuild(len1: usize, len2: usize) -> bool {
-    // log(1) == 0, so the inequation always falsy
-    // log(0) is inapplicable and produces panic
-    if len1 <= 1 {
-        return false;
-    }
-
-    2 * (len1 + len2) < len2 * log2_fast(len1)
-}
-
 #[cfg(feature = "serde")]
 #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 mod serde {

src/lib.rs

@@ -119,6 +119,7 @@ mod store;
 
 pub use crate::double_priority_queue::DoublePriorityQueue;
 pub use crate::priority_queue::PriorityQueue;
+use crate::store::log2_fast;
 
 use indexmap::TryReserveError as IndexMapTryReserveError;
 use std::collections::TryReserveError as StdTryReserveError;
@@ -161,3 +162,18 @@ impl From<IndexMapTryReserveError> for TryReserveError {
         }
     }
 }
+
+// `rebuild` takes O(len1 + len2) operations
+// and about 2 * (len1 + len2) comparisons in the worst case
+// while `extend` takes O(len2 * log_2(len1)) operations
+// and about 1 * len2 * log_2(len1) comparisons in the worst case,
+// assuming len1 >= len2.
+fn better_to_rebuild(len1: usize, len2: usize) -> bool {
+    // log(1) == 0, so the inequation always falsy
+    // log(0) is inapplicable and produces panic
+    if len1 <= 1 {
+        return false;
+    }
+
+    2 * (len1 + len2) < len2 * log2_fast(len1)
+}

src/priority_queue/mod.rs

@@ -35,7 +35,9 @@ pub mod iterators;
 #[cfg(not(feature = "std"))]
 use std::vec::Vec;
 
+use crate::better_to_rebuild;
 use crate::core_iterators::*;
+use crate::store::{left, parent, right};
 use crate::store::{Index, Position, Store};
 use crate::TryReserveError;
 use iterators::*;
@@ -977,42 +979,6 @@ where
     }
 }
 
-/// Compute the index of the left child of an item from its index
-#[inline(always)]
-const fn left(i: Position) -> Position {
-    Position((i.0 * 2) + 1)
-}
-/// Compute the index of the right child of an item from its index
-#[inline(always)]
-const fn right(i: Position) -> Position {
-    Position((i.0 * 2) + 2)
-}
-/// Compute the index of the parent element in the heap from its index
-#[inline(always)]
-const fn parent(i: Position) -> Position {
-    Position((i.0 - 1) / 2)
-}
-
-#[inline(always)]
-const fn log2_fast(x: usize) -> usize {
-    (usize::BITS - x.leading_zeros() - 1) as usize
-}
-
-// `rebuild` takes O(len1 + len2) operations
-// and about 2 * (len1 + len2) comparisons in the worst case
-// while `extend` takes O(len2 * log_2(len1)) operations
-// and about 1 * len2 * log_2(len1) comparisons in the worst case,
-// assuming len1 >= len2.
-fn better_to_rebuild(len1: usize, len2: usize) -> bool {
-    // log(1) == 0, so the inequation always falsy
-    // log(0) is inapplicable and produces panic
-    if len1 <= 1 {
-        return false;
-    }
-
-    2 * (len1 + len2) < len2 * log2_fast(len1)
-}
-
 #[cfg(feature = "serde")]
 #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 mod serde {

src/store.rs

@@ -46,10 +46,38 @@ use indexmap::map::{IndexMap, MutableKeys};
 /// The Index of the element in the Map
 #[derive(Copy, Clone, Debug, Ord, PartialOrd, Eq, PartialEq)]
 pub(crate) struct Index(pub usize);
+
 /// The Position of the element in the Heap
 #[derive(Copy, Clone, Debug, Ord, PartialOrd, Eq, PartialEq)]
 pub(crate) struct Position(pub usize);
 
+/// Compute the index of the left child of an item from its index
+#[inline(always)]
+pub(crate) const fn left(i: Position) -> Position {
+    Position((i.0 * 2) + 1)
+}
+/// Compute the index of the right child of an item from its index
+#[inline(always)]
+pub(crate) const fn right(i: Position) -> Position {
+    Position((i.0 * 2) + 2)
+}
+/// Compute the index of the parent element in the heap from its index
+#[inline(always)]
+pub(crate) const fn parent(i: Position) -> Position {
+    Position((i.0 - 1) / 2)
+}
+
+// Compute the level of a node from its index
+#[inline(always)]
+pub(crate) const fn level(i: Position) -> usize {
+    log2_fast(i.0 + 1)
+}
+
+#[inline(always)]
+pub(crate) const fn log2_fast(x: usize) -> usize {
+    (usize::BITS - x.leading_zeros() - 1) as usize
+}
+
 /// Internal storage of PriorityQueue and DoublePriorityQueue
 #[derive(Clone)]
 #[cfg(feature = "std")]