From 609d51c89e4764c0cbd422e0b172de57d5e02141 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Tue, 4 Jul 2017 16:24:54 +0200
Subject: [PATCH] bugfix in `CCList.split`

---
 src/core/CCList.ml | 34 +++++++++++-----------------------
 1 file changed, 11 insertions(+), 23 deletions(-)

diff --git a/src/core/CCList.ml b/src/core/CCList.ml
index fcc7a546..f044884c 100644
--- a/src/core/CCList.ml
+++ b/src/core/CCList.ml
@@ -389,44 +389,32 @@ let combine_gen l1 l2 =
 
 let split l = 
   let rec direct i l = match l with 
-    | [] -> ([],[])
+    | [] -> [], []
     | [x1, y1] -> [x1], [y1]
     | [x1, y1; x2, y2] -> [x1;x2], [y1;y2]
     | [x1, y1; x2, y2; x3, y3] -> [x1;x2;x3], [y1;y2;y3]
     | [x1, y1; x2, y2; x3, y3; x4, y4] -> [x1;x2;x3;x4], [y1;y2;y3;y4]
-    | _ when i=0 -> split_slow ([], []) l
-    | (x1, y1) ::
-        (x2, y2) ::
-        (x3, y3) ::
-        (x4, y4) ::
-        (x5, y5) :: l' ->
+    | _ when i=0 -> split_slow [] [] l
+    | (x1, y1) :: (x2, y2) :: (x3, y3) :: (x4, y4) :: (x5, y5) :: l' ->
       let rx, ry = direct (i-1) l' in 
       x1 :: x2 :: x3 :: x4 :: x5 :: rx,
       y1 :: y2 :: y3 :: y4 :: y5 :: ry
-  and split_slow acc l = match l with
-    | [] -> acc 
-    | (x1, y1) :: l' ->
-      let acc = x1 :: fst acc, y1 :: snd acc in 
-      split_slow acc l'
+  and split_slow acc1 acc2 l = match l with
+    | [] -> List.rev acc1, List.rev acc2
+    | (x1, x2) :: tail ->
+      let acc1 = x1 :: acc1
+      and acc2 = x2 :: acc2 in 
+      split_slow acc1 acc2 tail
   in 
   direct direct_depth_default_ l
 
 (*$Q 
-  (Q.(list (pair int string))) (fun l -> \
+  (Q.(list_of_size Gen.(0--10_000) (pair small_int small_string))) (fun l -> \
     let (l1, l2) = split l in \
     List.length l1 = List.length l \
     && List.length l2 = List.length l)
 
-  (Q.(list (pair string int))) (fun l -> \
-    let l = ("hello", 10) :: l in \
-    let (l1, l2) = split l in \
-    let i = Random.int @@ List.length l in \
-    let l1_x = List.nth l1 i in \
-    let l2_y = List.nth l2 i in \
-    let (x,y) = List.nth l i in \
-    l1_x = x && l2_y = y)
-
-  Q.(list (pair int int)) (fun l -> \
+  Q.(list_of_size Gen.(0--10_000) (pair small_int small_int)) (fun l -> \
     split l = List.split l)
 *)