From: Daniel Pittman <daniel@rimspace.net>
To: help-gnu-emacs@gnu.org
Subject: Re: Advice on writing predicates
Date: Fri, 26 Jun 2009 16:40:43 +1000 [thread overview]
Message-ID: <873a9n8plg.fsf@rimspace.net> (raw)
In-Reply-To: uhby454qg.fsf@raytheon.com
Sarir Khamsi <sarir.khamsi@raytheon.com> writes:
> I wrote a simple predicate that returns t if the Emacs major version number
> is greater than 22 and would like some advice/comments:
>
> The following
>
> (defun sk-emacs-version-greater-than23-p ()
> "Return non-nil if current Emacs version is greater than 22."
> (interactive)
> (setq version-string (replace-regexp-in-string ".*?\\([0-9]+\\)\.\\([0-9]+\\)\.\\([0-9]+\\)[()-.a-zA-Z0-9 \n]+" "\\1 \\2 \\3" (emacs-version)))
> (setq version-num (mapcar 'string-to-number (split-string version-string)))
> (if (> 22 (car version-num))
> t
> nil))
(defun dp/emacs-version-greater-than-23-p ()
"REVISIT: Document me, you fool!"
(interactive)
(> (string-to-number (car (split-string emacs-version "\\."))) 23))
That does two things better: first, it uses the emacs-version variable which
just holds the version number.
Second, it doesn't bother with a specific true value, just a generic one,
which the '>' function happily returns.
Regards,
Daniel
next prev parent reply other threads:[~2009-06-26 6:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-25 22:27 Advice on writing predicates Sarir Khamsi
2009-06-25 23:23 ` Anselm Helbig
2009-06-29 19:18 ` chickenphat
2009-06-26 6:40 ` Daniel Pittman [this message]
2009-06-26 7:37 ` Andreas Röhler
2009-06-26 9:13 ` Pascal J. Bourguignon
2009-06-26 11:02 ` Thien-Thi Nguyen
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