Return-Path: <cworth@cworth.org>
X-Original-To: notmuch@notmuchmail.org
Delivered-To: notmuch@notmuchmail.org
Received: from localhost (localhost [127.0.0.1])
	by olra.theworths.org (Postfix) with ESMTP id 2827B431FBD;
	Mon, 21 Dec 2009 17:23:57 -0800 (PST)
X-Virus-Scanned: Debian amavisd-new at olra.theworths.org
Received: from olra.theworths.org ([127.0.0.1])
	by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id 5QzIpCwZrpXB; Mon, 21 Dec 2009 17:23:56 -0800 (PST)
Received: from yoom.home.cworth.org (localhost [127.0.0.1])
	by olra.theworths.org (Postfix) with ESMTP id 3906F431FAE;
	Mon, 21 Dec 2009 17:23:56 -0800 (PST)
Received: by yoom.home.cworth.org (Postfix, from userid 1000)
	id E959F254306; Mon, 21 Dec 2009 17:23:55 -0800 (PST)
From: Carl Worth <cworth@cworth.org>
To: Ruben Pollan <meskio@sindominio.net>, notmuch@notmuchmail.org
In-Reply-To: <877hsv6hbo.fsf@yoom.home.cworth.org>
References: <20091126202347.GA16654@blackspot>
	<1260364206-344-1-git-send-email-meskio@sindominio.net>
	<20091209132446.GC23878@blackspot>
	<877hsv6hbo.fsf@yoom.home.cworth.org>
Date: Mon, 21 Dec 2009 17:23:55 -0800
Message-ID: <87r5qnol78.fsf@yoom.home.cworth.org>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-=";
	micalg=pgp-sha1; protocol="application/pgp-signature"
Subject: Re: [notmuch] [PATCH] Added regress option to tags iterator
X-BeenThere: notmuch@notmuchmail.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "Use and development of the notmuch mail system."
	<notmuch.notmuchmail.org>
List-Unsubscribe: <http://notmuchmail.org/mailman/options/notmuch>,
	<mailto:notmuch-request@notmuchmail.org?subject=unsubscribe>
List-Archive: <http://notmuchmail.org/pipermail/notmuch>
List-Post: <mailto:notmuch@notmuchmail.org>
List-Help: <mailto:notmuch-request@notmuchmail.org?subject=help>
List-Subscribe: <http://notmuchmail.org/mailman/listinfo/notmuch>,
	<mailto:notmuch-request@notmuchmail.org?subject=subscribe>
X-List-Received-Date: Tue, 22 Dec 2009 01:23:57 -0000

--=-=-=

On Wed, 09 Dec 2009 12:08:43 -0800, Carl Worth <cworth@cworth.org> wrote:
> On Wed, 9 Dec 2009 14:24:46 +0100, Ruben Pollan <meskio@sindominio.net> wrote:
> > Do you like to call them regress? Should I change that?
...
> > What about the functions notmuch_*_is_first? Is kind of reversed logic than
> > notmuch_*_has_more, the last are true when is not reach the limit but the
> > first ones are true when the limit is reached. But I think it make sense like
> > that.

It doesn't make sense in the case of trying to write a for loop that
iterates in the reverse order. The is_first semantic doesn't give you
what you want for the loop-control portion of the for loop.

> I'd like a more symmetric API here. Anyone have a favorite set of names
> for iterating a list in two directions?

In some recent coding I needed to implement a new iterator so I had the
chance to think about this some more. Here is what I came up with:

  New function		Corresponds to existing function (if any)
  ------------		-----------------------------------------
  move_to_first		<implicit in iterator creation>
  has_next		has_more
  move_to_next		advance

  move_to_last		<none>
  has_previous		<none>
  move_to_previous	<none>

  get			get

The semantics of those all seem clear enough to me. They provide what's
necessary for all three portions of a for loop, (in either direction),
and everything pairs nicely.

The only downside is that the function names are a bit long in some
cases, but I'm willing to live with that until someone comes up with
better.

Thoughts?

-Carl


--=-=-=
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)

iD8DBQFLMB+r6JDdNq8qSWgRArSAAJ49Ja9kHikoorvY/kXPqvAgbTNCCQCggdyz
vrtsxqN6BecsttfhBstYQwc=
=RxAS
-----END PGP SIGNATURE-----
--=-=-=--