From 19576effbe1fb632f3a5ca0ceda6105068d0fd42 Mon Sep 17 00:00:00 2001
From: Felix Riedel <felix.riedel@gmail.com>
Date: Sun, 3 Jan 2021 20:09:50 +0000
Subject: [PATCH] Revert "Tweak sort: use insertion sort for small arrays"
This reverts commit 0ea77cabfb30afc15433581f5888171c1f65aafd.
---
src/boot/boot.janet | 53 ++++++++++++++++++---------------------------
1 file changed, 21 insertions(+), 32 deletions(-)
diff --git a/src/boot/boot.janet b/src/boot/boot.janet
index 58281d39..afec07d9 100644
--- a/src/boot/boot.janet
+++ b/src/boot/boot.janet
@@ -795,45 +795,34 @@
a
(if (not= (> b a) (> b c)) b c)))
-(defn- insertion-sort [a lo hi by]
- (for i (+ lo 1) (+ hi 1)
- (def temp (in a i))
- (var j (- i 1))
- (while (and (>= j lo) (by temp (in a j)))
- (set (a (+ j 1)) (in a j))
- (-- j))
-
- (set (a (+ j 1)) temp))
+(defn sort-help [a lo hi by]
+ (when (< lo hi)
+ (def pivot
+ (median-of-three (in a hi) (in a lo)
+ (in a (math/floor (/ (+ lo hi) 2)))))
+ (var left lo)
+ (var right hi)
+ (while true
+ (while (by (in a left) pivot) (++ left))
+ (while (by pivot (in a right)) (-- right))
+ (when (<= left right)
+ (def tmp (in a left))
+ (set (a left) (in a right))
+ (set (a right) tmp)
+ (++ left)
+ (-- right))
+ (if (>= left right) (break)))
+ (sort-help a lo right by)
+ (sort-help a left hi by))
a)
(defn sort
"Sort an array in-place. Uses quick-sort and is not a stable sort."
[a &opt by]
- (default by <)
- (def stack @[[0 (- (length a) 1)]])
- (while (not (empty? stack))
- (def [lo hi] (array/pop stack))
- (when (< lo hi)
- (when (< (- hi lo) 32) (insertion-sort a lo hi by) (break))
- (def pivot (median-of-three (in a hi) (in a lo) (in a (math/floor (/ (+ lo hi) 2)))))
- (var left lo)
- (var right hi)
- (while true
- (while (by (in a left) pivot) (++ left))
- (while (by pivot (in a right)) (-- right))
- (when (<= left right)
- (def tmp (in a left))
- (set (a left) (in a right))
- (set (a right) tmp)
- (++ left)
- (-- right))
- (if (>= left right) (break)))
- (array/push stack [lo right])
- (array/push stack [left hi])))
- a)
+ (sort-help a 0 (- (length a) 1) (or by <)))
(undef median-of-three)
-(undef insertion-sort)
+(undef sort-help)
(defn sort-by
`Returns a new sorted array that compares elements by invoking