From: Jim Pryor <profjim@jimpryor.net>
Date: Sun, 5 Dec 2010 15:35:25 +0000 (-0500)
Subject: tree_monadize tweaks
X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=c9a9cb39ae6852c63c43d80ed4ebb05aec6c1e05

tree_monadize tweaks

Signed-off-by: Jim Pryor <profjim@jimpryor.net>
---

diff --git a/code/tree_monadize.ml b/code/tree_monadize.ml
index 08b8d690..7c419a34 100644
--- a/code/tree_monadize.ml
+++ b/code/tree_monadize.ml
@@ -196,6 +196,36 @@ let int_readerize : int -> int Reader_monad.monad =
 let env = fun i -> i + i in
 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:
+ *     ...
+ *     let module T = Tree_monadizer(Reader_monad) in
+ *     T.monadize int_readerize t1 env;;
+ * or:
+ *     ...
+ *     let env = fun i -> i + i in
+ *     let module Monad = struct
+ *       type env = int -> int;;
+ *       type 'a monad = env -> 'a;;
+ *       let unit a : 'a monad = fun e -> a;;
+ *       let bind (u : 'a monad) (f : 'a -> 'b monad) : 'b monad =
+ *         fun e -> f (u e) e;;
+ *     end in
+ *     let module T = Tree_monadizer(Monad) in
+ *     T.monadize int_readerize t1 env;;
+ * or:
+ *     ...
+ *     let module T = Tree_monadizer(struct
+ *       type env = int -> int;;
+ *       type 'a monad = env -> 'a;;
+ *       let unit a : 'a monad = fun e -> a;;
+ *       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;;
+ *)
+
+
 (* square each leaf *)
 let env = fun i -> i * i in
 TreeReader.monadize int_readerize t1 env;;
@@ -239,4 +269,3 @@ TreeCont.monadize (fun a k -> k [a; a*a]) t1 initial_continuation;;
 let initial_continuation = fun t -> 0 in
 TreeCont.monadize (fun a k -> 1 + k a) t1 initial_continuation;;
 
-