Add the flatten (concat) function

Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/my_list.mli b/my_list.mli
index 72535d5..4644a74 100644
--- a/my_list.mli
+++ b/my_list.mli
@@ -70,3 +70,8 @@ let rec append l1 l2 =
 (** Return a list which results in the concatenation of reversed l1 and l2. *)
 let rev_append l1 l2 =
     append (rev l1) l2
+
+(** Return a list consisting of the contenation of the given list of lists. *)
+let rec flatten = function
+    | Item(hd, tl) -> append hd (flatten tl)
+    | None -> None