benchmark.splay: adding a splay-tree benchmark.

extra/benchmark/splay/splay.factor

@@ -0,0 +1,18 @@
+
+USING: arrays assocs kernel math.ranges random sequences sets
+sorting trees.splay ;
+
+IN: splay
+
+: initial-alist ( n -- alist )
+    iota >array randomize dup zip ;
+
+: change-random ( newkeys splay keys -- splay' )
+    swapd [ first pick delete-at first2 pick set-at ] 2each ;
+
+: run-splay ( -- )
+    100,000 initial-alist 10,000 cut
+    [ >splay ] [ randomize 10,000 head ] bi
+    change-random keys dup natural-sort assert= ;
+
+MAIN: run-splay