Use reverse and fold instead of append

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gleam/list.gleam b/src/gleam/list.gleam
index 1fcd2d8..4745f43 100644
--- a/src/gleam/list.gleam
+++ b/src/gleam/list.gleam
@@ -1474,7 +1474,12 @@ pub fn combinations(items: List(a), by n: Int) -> List(List(a)) {
         [x, ..xs] -> {
           let first_combinations =
             map(combinations(xs, n - 1), with: fn(com) { [x, ..com] })
-          append(first_combinations, combinations(xs, n))
+            |> reverse
+          fold(
+            first_combinations,
+            combinations(xs, n),
+            fn(c, acc) { [c, ..acc] },
+          )
         }
       }
   }