From 52cbf99e0db1c0fb7b44f4101c6a673d9ec1fbbe Mon Sep 17 00:00:00 2001
From: Sébastien Dailly <sebastien@dailly.me>
Date: Mon, 7 Feb 2022 15:48:26 +0100
Subject: Update application workflow
---
lib/application/application.ml | 58 +++++++++++++++++++++++++++++++++++-------
1 file changed, 49 insertions(+), 9 deletions(-)
(limited to 'lib/application')
diff --git a/lib/application/application.ml b/lib/application/application.ml
index 15452fb..63e12ba 100755
--- a/lib/application/application.ml
+++ b/lib/application/application.ml
@@ -1,9 +1,49 @@
-(** The type for the applcation *)
-type ('a, 'b) t = 'a -> 'b -> 'b
-
-(** Simple helper for the main event loop *)
-let run
- : ?eq:('b -> 'b -> bool) -> ('a, 'b) t -> 'b -> 'a Note.E.t -> 'b Note.S.t
- = fun ?eq f init event ->
- let action = Note.E.map f event in
- Note.S.accum ?eq init action
+(** The Make module build the main application loop.contents
+
+ The function [run] update the state on each event, and return a new state.
+ Each event must follow the [event] type, which is composed from the type
+ [t], and a module with a fonction [update].
+
+ This example create an application with the state containing a simple
+ counter. An even which increment this counter is created and can be used to
+ update the state.
+
+
+ [
+ type state = { value : int }
+
+ (** Increment the state *)
+ module Incr = struct
+ type t = unit
+
+ let update () state = { value = state.value + 1 }
+ end
+
+ module App = Make(struct type t = state end)
+
+ (* Create the event itself *)
+ let incr_event = App.E ((), (module Incr:App.Event with type t = Incr.t))
+
+ ]
+
+*)
+module Make(S:sig type t end) = struct
+ module type Event = sig
+
+ type t
+
+ val update: t -> S.t -> S.t
+
+ end
+
+ type event = E : 'a * (module Event with type t = 'a) -> event
+
+ (** Simple helper for the main event loop *)
+ let run
+ : ?eq:(S.t -> S.t -> bool) -> S.t -> event Note.E.t -> S.t Note.S.t
+ = fun ?eq init event ->
+ let action = Note.E.map (fun (E (t, (module Event))) st -> Event.update t st) event in
+ Note.S.accum ?eq init action
+end
+
+
--
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