module Tree_monadizer(X : sig
(* the module we're using as a parameter has to supply function values
- * for unit and bind, as well as a monadic type constructor m *)
+ * for unit and bind, as well as a monadic type constructor *)
type 'a monad
val unit : 'a -> 'a monad
val bind : 'a monad -> ('a -> 'b monad) -> 'b monad
TreeReader.monadize int_readerize t1 env;;
(* You can also avoid declaring a separate toplevel TreeReader module
- * (or even a separate Reader_monad module) by ysing one of these forms:
+ * (or even a separate Reader_monad module) by using one of these forms:
* ...
* let module T = Tree_monadizer(Reader_monad) in
* T.monadize int_readerize t1 env;;
let initial_continuation = fun t -> 0 in
TreeCont.monadize (fun a k -> 1 + k a) t1 initial_continuation;;
+(*
+(* Tree monad *)
+
+(* type 'a tree defined above *)
+let tree_unit (a: 'a) : 'a tree = Leaf a;;
+let rec tree_bind (u : 'a tree) (f : 'a -> 'b tree) : 'b tree =
+ match u with
+ | Leaf a -> f a
+ | Node (l, r) -> Node (tree_bind l f, tree_bind r f);;
+
+type ('a) treeT_reader =
+ 'a tree reader;;
+
+let unit (a: 'a) : 'a tree reader =
+ reader_unit (Leaf a);;
+
+let rec bind (u : 'a tree_reader) (f : 'a -> ('b, M) tree) : ('b, M) tree =
+ match u with
+ | Leaf a -> M.bind (f a) (fun b -> M.unit (Leaf b))
+ | Node (l, r) -> M.bind (bind l f) (fun l' ->
+ M.bind (bind r f) (fun r' ->
+ M.unit (Node (l', r'));;
+
+ *)