--- a/dune	Sun Jul 23 18:29:01 2023 +0200
+++ b/dune	Sun Sep 24 18:16:08 2023 +0200
@@ -38,7 +38,6 @@
   (inline_tests)
   (preprocess (pps ppx_inline_test ppx_assert ppx_sexp_value))
   (libraries myqueue base))
-
 (env
   (dev
     (flags (:standard -w -32-33))))

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/list/List_queue.ml	Sun Sep 24 18:16:08 2023 +0200
@@ -0,0 +1,83 @@
+module List = struct
+  type 'a node = {
+    mutable prev : 'a node option;
+    mutable next : 'a node option;
+    data : 'a;
+  }
+
+  type 'a t = {
+    mutable head : 'a node option;
+    mutable tail : 'a node option;
+    mutable length : int;
+  }
+
+  let node data = { prev = None; next = None; data }
+  let empty () = { head = None; tail = None; length = 0 }
+
+  let add l e =
+    let n = node e in
+    match l.head with
+    | None ->
+        l.head <- Some n;
+        l.tail <- Some n;
+        l.length <- l.length + 1
+    | Some h ->
+        n.next <- l.head;
+        h.prev <- Some n;
+        l.head <- Some n;
+        l.length <- l.length + 1
+
+  let pop l =
+    match l.tail with
+    | None -> None
+    | Some n ->
+        l.tail <- n.prev;
+        n.prev <- None;
+        l.length <- l.length - 1;
+        Some n.data
+
+  let rec of_list = function
+    | [] -> empty ()
+    | x :: xs ->
+        let l = of_list xs in
+        add l x;
+        l
+
+  let rec to_list = function
+    | { head = Some h; tail; length } ->
+        h.data :: to_list { head = h.next; tail; length = length - 1 }
+    | { head = None; _ } -> []
+
+  let length l = l.length
+end
+
+let%test "list_length" =
+  let l = List.empty () in
+  let m = List.empty () in
+  let eq = Int.equal in
+  List.add m 222;
+  List.add m 333;
+  eq (List.length l) 0 && eq (List.length m) 2
+
+let%test "list_order" =
+  let l = List.empty () in
+  List.add l 1;
+  List.add l 2;
+  Option.equal Int.equal (List.pop l) (Some 1)
+
+let%test "of_list" =
+  let l = List.of_list [ 1; 2; 3; 4 ] in
+  let eq x y = Option.equal Int.equal x y in
+  let p0 = List.length l == 4 in
+  let p1 = eq (List.pop l) (Some 4) in
+  let p2 = eq (List.pop l) (Some 3) in
+  let p3 = eq (List.pop l) (Some 2) in
+  let p4 = eq (List.pop l) (Some 1) in
+  let p5 = eq (List.pop l) None in
+  p0 && p1 && p2 && p3 && p4 && p5
+
+let%test "to_list" =
+  let orig = [ 1; 2; 3; 4 ] in
+  let l = List.of_list orig in
+  let ll = List.to_list l in
+  Base.List.equal Int.equal orig ll

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/list/dune	Sun Sep 24 18:16:08 2023 +0200
@@ -0,0 +1,10 @@
+
+
+(library
+  (name list_queue)
+  (modules List_queue)
+  (inline_tests)
+  (preprocess (pps ppx_inline_test ppx_assert))
+  (libraries)
+  )
+