X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=code%2Ftree_monadize.ml;h=d23606f95e3dd1c31870aa9a770f9be06d4be56e;hp=7c419a342402ce77a965eb1c2810e4b332cdfcde;hb=ebe5f10b42f512f81bfc9e4c19c361b3010c72f9;hpb=ff95f5a38d61a6fa0b9c5e4da4253a6a3266a7dc

diff --git a/code/tree_monadize.ml b/code/tree_monadize.ml
index 7c419a34..d23606f9 100644
--- a/code/tree_monadize.ml
+++ b/code/tree_monadize.ml
@@ -115,12 +115,12 @@ let t1 = Node
 
 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
 end) = struct
-  let rec monadize (f: 'a -> 'b X.monad) (t: 'a tree) : 'b tree X.monad =
+  let rec monadize (t: 'a tree) (f: 'a -> 'b X.monad) : 'b tree X.monad =
     match t with
     | Leaf a -> X.bind (f a) (fun b -> X.unit (Leaf b))
     | Node(l, r) ->
@@ -164,7 +164,7 @@ module Tree_monadizer2(X : sig
 end) = struct
   (* the body of the monadize function is the same; the only difference is in
    * the types *)
-  let rec monadize (f: 'a -> ('b,'x) X.monad) (t: 'a tree) : ('b tree,'x) X.monad =
+  let rec monadize (t: 'a tree) (f: 'a -> ('b,'x) X.monad) : ('b tree,'x) X.monad =
     match t with
     | Leaf a -> X.bind (f a) (fun b -> X.unit (Leaf b))
     | Node(l, r) ->
@@ -194,13 +194,13 @@ let int_readerize : int -> int Reader_monad.monad =
 
 (* double each leaf *)
 let env = fun i -> i + i in
-TreeReader.monadize int_readerize t1 env;;
+TreeReader.monadize t1 int_readerize 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;;
+ *     T.monadize t1 int_readerize env;;
  * or:
  *     ...
  *     let env = fun i -> i + i in
@@ -212,7 +212,7 @@ TreeReader.monadize int_readerize t1 env;;
  *         fun e -> f (u e) e;;
  *     end in
  *     let module T = Tree_monadizer(Monad) in
- *     T.monadize int_readerize t1 env;;
+ *     T.monadize t1 int_readerize env;;
  * or:
  *     ...
  *     let module T = Tree_monadizer(struct
@@ -222,13 +222,13 @@ TreeReader.monadize int_readerize t1 env;;
  *       let bind (u : 'a monad) (f : 'a -> 'b monad) : 'b monad =
  *         fun e -> f (u e) e;;
  *     end) in
- *     T.monadize int_readerize t1 env;;
+ *     T.monadize t1 int_readerize env;;
  *)
 
 
 (* square each leaf *)
 let env = fun i -> i * i in
-TreeReader.monadize int_readerize t1 env;;
+TreeReader.monadize t1 int_readerize env;;
 
 
 
@@ -240,32 +240,56 @@ let incrementer : int -> int State_monad.monad =
 
 (* count leaves *)
 let initial_store = 0 in
-TreeState.monadize incrementer t1 initial_store;;
+TreeState.monadize t1 incrementer initial_store;;
 
 
 
 (* replace leaves with list *)
-TreeList.monadize (fun i -> [ [i;i*i] ]) t1;;
+TreeList.monadize t1 (fun i -> [ [i;i*i] ]);;
 
 
 
 (* do nothing *)
 let initial_continuation = fun t -> t in
-TreeCont.monadize Continuation_monad.unit t1 initial_continuation;;
+TreeCont.monadize t1 Continuation_monad.unit initial_continuation;;
 
 (* convert tree to list of leaves *)
 let initial_continuation = fun t -> [] in
-TreeCont.monadize (fun a k -> a :: k a) t1 initial_continuation;;
+TreeCont.monadize t1 (fun a k -> a :: k a) initial_continuation;;
 
 (* square each leaf using continuation *)
 let initial_continuation = fun t -> t in
-TreeCont.monadize (fun a k -> k (a*a)) t1 initial_continuation;;
+TreeCont.monadize t1 (fun a k -> k (a*a)) initial_continuation;;
 
 (* replace leaves with list, using continuation *)
 let initial_continuation = fun t -> t in
-TreeCont.monadize (fun a k -> k [a; a*a]) t1 initial_continuation;;
+TreeCont.monadize t1 (fun a k -> k [a; a*a]) initial_continuation;;
 
 (* count leaves, using continuation *)
 let initial_continuation = fun t -> 0 in
-TreeCont.monadize (fun a k -> 1 + k a) t1 initial_continuation;;
+TreeCont.monadize t1 (fun a k -> 1 + k a) 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'));;
+
+ *)