From: "Sebastien Vauban" <wxhgmqzgwmuf-geNee64TY+gS+FvcfC7Uqw@public.gmane.org>
To: help-gnu-emacs-mXXj517/zsQ@public.gmane.org
Subject: Re: Interesting problem: eval-after-load and local variables
Date: Wed, 17 Oct 2012 10:32:55 +0200 [thread overview]
Message-ID: <808vb58pmw.fsf@somewhere.org> (raw)
In-Reply-To: mailman.11151.1350444234.855.help-gnu-emacs@gnu.org
Hi Kevin,
Kevin Rodgers wrote:
> On 10/16/12 2:02 AM, Sebastien Vauban wrote:
>> In order to speed up my Emacs startup, I've put many customizations in
>> eval-after-load's, such as:
>>
>> --8<---------------cut here---------------start------------->8---
>> (eval-after-load "time-stamp"
>> '(progn
>> ;; format of the string inserted by `M-x time-stamp'
>> (setq time-stamp-format "%:y-%02m-%02d %3a %02H:%02M %u")))
>> --8<---------------cut here---------------end--------------->8---
>>
>> in order to avoid the require itself in the .emacs file.
>
> In general, it is not necessary to load a library before customizing its global
> options. You should get the desired effect with just:
>
> (setq time-stamp-format "%:y-%02m-%02d %3a %02H:%02M %u")
I know. And this is a very somewhat ridiculous example. But, for speed and
clarity of my .emacs, I've generally put all customs inside an
eval-after-load. A setq is certainly not time-taker, certainly not when alone,
but I've applied the same principal to many other blocks of customs.
>> Now, this causes a problem, as my local variable customizations aren't
>> respected anymore.
>>
>> For example, I have the following local vars in my file `common.sty' to set up
>> the format of the time-stamp (à la LaTeX):
>>
>> --8<---------------cut here---------------start------------->8---
>> %% common.sty -- LaTeX common commands and environments
>>
>> \NeedsTeXFormat{LaTeX2e}
>> \ProvidesPackage{common}[2012/10/15 v1.0 Common stuff between documents and presentations]
>>
>> % ...
>>
>> %% End of package
>> \endinput % very last line
>>
>> % Local Variables:
>> % time-stamp-format: "%:y/%02m/%02d"
>> % time-stamp-start: "Provides\\(Class\\|Package\\){[a-zA-Z-]+}\\["
>> % time-stamp-end: " "
>> % End:
>> --8<---------------cut here---------------end--------------->8---
>>
>> The problem is the following:
>>
>> - Upon opening the file, Emacs sees it needs to load time-stamp.
>
> I don't see how, since those variables aren't autoloaded. (Their autoload
> cookies only result in the safe-local-variable property being dumped into the
> emacs executable for each symbol.) I suspect you have enabled time stamp as
> documented in the Emacs manual:
>
> Then add the hook function `time-stamp' to the hook
> `before-save-hook'; that hook function will automatically update the
> time stamp, inserting the current date and time when you save the file.
>
> (The function time-stamp is autoloaded.)
You're absolutely right! I described the correct effect, but not the right
cause...
>> - It does it (via the predefined autoloads), but the eval-after-load overrides
>> the local variables' value.
>
> Yes, because the eval-after-load form is apparently evaluated while the
> common.sty buffer is current, and the file local variable section has already
> made each variable local to that buffer.
>
>> - When saving the file, the time-stamp format provided in local vars is NOT
>> applied.
>
> Actually, I think the file local variables are applied and then overridden by
> the eval-after-load form (but only for the first file that you save).
Your explanation must be right. But my question was more general, in the
sense: is this the behavior one would expect? Or *should local vars triumph
over the setq done in the eval-after-load?*
> Do other files with time stamp templates work as intended?
I'll check (but I've already applied the fix suggested by Michael). I guess
the answer is yes.
>> In a way, that's perfectly normal. In another, not at all: I would expect the
>> local vars to win over the wide values, in any configuration (even if my setq
>> were in an eval-after-load construct).
>>
>> What do you think?
>
> I think you should either skip the eval-after-load boilerplate
As said, for this example: you're definitively right. It's kind of useless.
> or use setq-default in the eval-after-load form as suggested by Michael.
Can I use setq-default with whichever var? I guess not. But am I right?
Best regards,
Seb
--
Sebastien Vauban
next prev parent reply other threads:[~2012-10-17 8:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-16 8:02 Interesting problem: eval-after-load and local variables Sebastien Vauban
2012-10-16 9:18 ` Peter Dyballa
2012-10-16 17:54 ` Michael Heerdegen
2012-10-17 3:23 ` Kevin Rodgers
[not found] ` <mailman.11151.1350444234.855.help-gnu-emacs@gnu.org>
2012-10-17 8:32 ` Sebastien Vauban [this message]
2012-10-18 4:09 ` Michael Heerdegen
2012-10-18 12:55 ` Kevin Rodgers
2012-10-18 17:46 ` Bob Proulx
[not found] ` <mailman.11221.1350564945.855.help-gnu-emacs@gnu.org>
2012-10-19 9:40 ` Sebastien Vauban
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