- Fixed a bug when converting an array into a list (also improved the performance).

1 files changed, 13 insertions, 11 deletions

diff --git a/stdlib/source/lux/data/coll/array.lux b/stdlib/source/lux/data/coll/array.lux
index 833da6230..a4a3aa903 100644
--- a/stdlib/source/lux/data/coll/array.lux
+++ b/stdlib/source/lux/data/coll/array.lux
@@ -133,19 +133,21 @@
                             [+0 (new (list;size xs))]
                             xs)))
 
+(def: underflow Nat (n.dec +0))
+
 (def: #export (to-list array)
   (All [a] (-> (Array a) (List a)))
-  (let [_size (size array)]
-    (product;right (list/fold (function [_ [idx tail]]
-                                (case (read idx array)
-                                  (#;Some head)
-                                  [(n.dec idx) (#;Cons head tail)]
-
-                                  #;None
-                                  [(n.dec idx) tail]))
-                              [(n.dec _size) #;Nil]
-                              (list;repeat _size [])
-                              ))))
+  (loop [idx (n.dec (size array))
+         output #;Nil]
+    (if (n.= underflow idx)
+      output
+      (recur (n.dec idx)
+             (case (read idx array)
+               (#;Some head)
+               (#;Cons head output)
+
+               #;None
+               output)))))
 
 (struct: #export (Eq<Array> Eq<a>)
   (All [a] (-> (Eq a) (Eq (Array a))))