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From: Guillaume Yziquel <guillaume.yziquel@citycable.ch>
To: "OCaml List" <caml-list@inria.fr>,
	"Daniel Bünzli" <daniel.buenzli@erratique.ch>
Subject: Recursion on React.events.
Date: Wed, 09 Dec 2009 03:40:58 +0100	[thread overview]
Message-ID: <4B1F0E3A.3040907@citycable.ch> (raw)

Hello.

I've been dabbling with recursive definition of React events.

Suppose I have a function called schedule of type

	val schedule : Calendar.t -> unit React.event

which throws out an event at the specified time or date.

I've been trying to create a regular_schedule function that throws 
events at a regular pace. Daniel Bünzli's module is great, but sometimes 
a bit rough to get by, specifically on examples such as this one.

So I came up with a recursive definition of such a React.event:

> let rec regular_schedule start_time period =
>   React.E.switch React.E.never begin React.E.map
>     begin fun () -> regular_schedule (Calendar.add (Calendar.now ()) period) period end
>     begin schedule start_time end
>   end

First question:

It almost works, in the sense that if you insert a print_endline after 
the fun (), well, it indeeds prints stuff on stdin at the specified 
pace. However, somehow, the event as a whole behaves as React.E.never. 
So it doesn't work. I guess it has to do with the way React.switch works 
synchronously, but I really do not get it.

Second question:

Is there somehow a notion of 'tail recursion' for such constructs?

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/


             reply	other threads:[~2009-12-09  2:40 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-09  2:40 Guillaume Yziquel [this message]
2009-12-09  3:22 ` Guillaume Yziquel
2009-12-09  4:25 ` Daniel Bünzli
2009-12-09 18:47   ` Guillaume Yziquel
2009-12-10  8:39     ` Daniel Bünzli
2009-12-09  7:53 ` Daniel Bünzli
2009-12-09 11:23   ` [Caml-list] " Richard Jones
2009-12-09 18:01     ` Guillaume Yziquel
2009-12-10  3:38       ` Daniel Bünzli
2009-12-10 22:24         ` Guillaume Yziquel
2009-12-11 12:16           ` Jérémie Dimino
2009-12-09 18:24   ` Guillaume Yziquel
2009-12-10  8:24     ` Daniel Bünzli
2009-12-10 21:41       ` Guillaume Yziquel
2009-12-11  1:22         ` Daniel Bünzli

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