From ca8c7b4db44e8126837c588b97d973845f5ccb52 Mon Sep 17 00:00:00 2001
From: John Benediktsson <mrjbq7@gmail.com>
Date: Tue, 5 Mar 2013 20:01:27 -0800
Subject: [PATCH] grouping: faster all-eq? and all-equal? (fewer comparisons).

---
 basis/grouping/grouping.factor | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/basis/grouping/grouping.factor b/basis/grouping/grouping.factor
index 99cefa3cf0..8c49f0d903 100644
--- a/basis/grouping/grouping.factor
+++ b/basis/grouping/grouping.factor
@@ -106,9 +106,23 @@ INSTANCE: sliced-clumps abstract-clumps
         ] if
     ] if ; inline
 
-: all-equal? ( seq -- ? ) [ = ] monotonic? ;
+: all-equal? ( seq -- ? )
+    dup length dup 2 < [ 2drop t ] [
+        2 = [
+            first2-unsafe =
+        ] [
+            dup first-unsafe [ = ] curry all?
+        ] if
+    ] if ;
 
-: all-eq? ( seq -- ? ) [ eq? ] monotonic? ;
+: all-eq? ( seq -- ? )
+    dup length dup 2 < [ 2drop t ] [
+        2 = [
+            first2-unsafe eq?
+        ] [
+            dup first-unsafe [ eq? ] curry all?
+        ] if
+    ] if ;
 
 TUPLE: circular-slice { from read-only } { to read-only } { seq read-only } ;