2 files changed, 54 insertions, 11 deletions
diff --git a/lib.c b/lib.c
index 4883e08b..206eead7 100644
--- a/lib.c
+++ b/lib.c
@@ -9491,17 +9491,27 @@ static val window_map_list(val range, val boundary, val fun, val list,
 
   args_set_fill(args, ws);
 
-  if (boundary == wrap_k) {
-    val lcopy = take(range, list);
-    while (lt(length(lcopy), range))
-      lcopy = append2(lcopy, lcopy);
-    boundary = append2(sub(lcopy, num_fast(-ra), t), sub(lcopy, zero, range));
-  } else if (boundary == reflect_k) {
-    val lcopy = take(range, list);
-    while (lt(length(lcopy), range))
-      lcopy = append2(lcopy, lcopy);
-    boundary = nappend2(nreverse(sub(lcopy, zero, range)),
-                        nreverse(sub(lcopy, num_fast(-ra), t)));
+  if (boundary == wrap_k || boundary == reflect_k) {
+    val lw = sub(list, num_fast(-ra), t), lwing = lw;
+    val rw = sub(list, zero, range), rwing = rw;
+    cnum i, len = c_fixnum(length(list), self);
+
+    if (boundary == reflect_k) {
+      lwing = reverse(rw);
+      rwing = reverse(lw);
+      lw = lwing;
+      rw = rwing;
+    }
+
+    for (i = len; i < ra; i += len) {
+      lwing = append2(lwing, lw);
+      rwing = append2(rwing, rw);
+    }
+
+    if (len < ra)
+      boundary = append2(sub(lwing, num_fast(-ra), t), sub(rwing, zero, range));
+    else
+      boundary = append2(lwing, rwing);
   }
 
   for (i = 0; i < ra; i++)
diff --git a/tests/012/seq.tl b/tests/012/seq.tl
index 1bb4ddcc..b38d226f 100644
--- a/tests/012/seq.tl
+++ b/tests/012/seq.tl
@@ -20,3 +20,36 @@
 
 (test (mapcar (lambda (. args) (list . args)) '#(1 2 3) '#(4 5 6))
       #((1 4) (2 5) (3 6)))
+
+(test [window-map 2 '(x x) list '(a b c d e f g)]
+      ((x x a b c) (x a b c d) (a b c d e)
+       (b c d e f) (c d e f g) (d e f g nil)
+       (e f g nil nil)))
+
+(test [window-map 2 '(x x y y) list '(a b c d e f g)]
+      ((x x a b c) (x a b c d) (a b c d e)
+       (b c d e f) (c d e f g) (d e f g y)
+       (e f g y y)))
+
+(test [window-map 2 nil list '(a b c d e f g)]
+      ((nil nil a b c) (nil a b c d) (a b c d e)
+       (b c d e f) (c d e f g)
+       (d e f g nil) (e f g nil nil)))
+
+(test [window-map 2 :wrap list '(a b c d e f g)]
+      ((f g a b c) (g a b c d) (a b c d e) (b c d e f)
+       (c d e f g) (d e f g a) (e f g a b)))
+
+(test [window-map 2 :reflect list '(a b c d e f g)]
+      ((b a a b c) (a a b c d) (a b c d e) (b c d e f)
+       (c d e f g) (d e f g g) (e f g g f)))
+
+(test [window-map 7 :wrap list '(a b c)]
+      ((c a b c a b c a b c a b c a b)
+       (a b c a b c a b c a b c a b c)
+       (b c a b c a b c a b c a b c a)))
+
+(test [window-map 7 :reflect list '(a b c)]
+      ((a c b a c b a a b c c b a c b)
+       (c b a c b a a b c c b a c b a)
+       (b a c b a a b c c b a c b a c)))