fix bug in List.map reverseUnrolledMap

was ignoring some list elements

Author: matthewleon

src/Data/List/Types.purs

@@ -108,8 +108,8 @@ listMap f = startUnrolledMap unrollLimit where
       reverseUnrolledMap chunksAcc $ startUnrolledMap 0 finalChunk
 
     reverseUnrolledMap :: List (List a) -> List b -> List b
-    reverseUnrolledMap ((x1 : x2 : x3 : _) : cs) acc =
-      reverseUnrolledMap cs (f x1 : f x2 : f x3 : acc)
+    reverseUnrolledMap ((x1 : x2 : x3 : x4 : x5 : _) : cs) acc =
+      reverseUnrolledMap cs (f x1 : f x2 : f x3 : f x4 : f x5 : acc)
     -- if we pattern match on Nil, we need a Partial constraint,
     -- which kills TCO
     reverseUnrolledMap _ acc = acc

test/Test/Data/List.purs

@@ -363,6 +363,9 @@ testList = do
   log "map should be stack-safe"
   void $ pure $ map id (1..100000)
 
+  log "map should be correct"
+  assert $ (1..1000000) == map (_ + 1) (0..999999)
+
   log "transpose"
   assert $ transpose (l [l [1,2,3], l[4,5,6], l [7,8,9]]) ==
                      (l [l [1,4,7], l[2,5,8], l [3,6,9]])