math.combinatorics: fix selections bug, geez.

2018-01-17 13:59:22 -08:00 · 2018-01-17 13:59:22 -08:00 · 1beaa8f494
parent 9d35cd9048
commit 1beaa8f494
1 changed files with 2 additions and 2 deletions
--- a/basis/math/combinatorics/combinatorics.factor
+++ b/basis/math/combinatorics/combinatorics.factor
@ -253,9 +253,9 @@ PRIVATE>

 :: next-selection ( seq n -- )
    1 seq length 1 - [
-        over 0 =
+        dup 0 >= [ over 0 = ] [ t ] if
    ] [
-        [ seq [ + n /mod ] change-nth-unsafe ] keep 1 -
+        [ seq [ + n /mod ] change-nth ] keep 1 -
    ] do until 2drop ; inline

 :: (selections) ( seq n -- selections )