bug#7986: 23.2.91; Remove unwise advice from manual

bug#7986: 23.2.91; Remove unwise advice from manual

[Reuben Thomas]

In “Hooks for Loading” the manual says:

   But it is OK to use `eval-after-load' in your personal
customizations if you don't feel that they must meet the design
standards for programs meant for wider use.

This sort of advice tends to be unwise to give, because people write
code for their own use, then later distribute it and forget to clean it
up. In any case, the solutions in this case, as explained in the
previous paragraph:

   Normally, well-designed Lisp programs should not use
`eval-after-load'.  If you need to examine and set the variables
defined in another library (those meant for outside use), you can do it
immediately--there is no need to wait until the library is loaded.  If
you need to call functions defined by that library, you should load the
library, preferably with `require' (*note Named Features::).

are easier to write than the bad code. Hence, I suggest the offending
paragraph (the first one I quoted above) be removed.


In GNU Emacs 23.2.91.4 (i686-pc-linux-gnu, GTK+ Version 2.22.0)
 of 2011-01-13 on canta
Windowing system distributor `The X.Org Foundation', version 11.0.10900000
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-- 
http://rrt.sc3d.org/

bug#7986: 23.2.91; Remove unwise advice from manual

[Lennart Borgman]

On Sat, Feb 5, 2011 at 12:26 AM, Reuben Thomas <rrt@sc3d.org> wrote:
>
>   Normally, well-designed Lisp programs should not use
> `eval-after-load'.  If you need to examine and set the variables
> defined in another library (those meant for outside use), you can do it
> immediately--there is no need to wait until the library is loaded.  If
> you need to call functions defined by that library, you should load the
> library, preferably with `require' (*note Named Features::).

You can't do that. Just imagine you write a library with one single
purpose: doing something after another library is loaded.

bug#7986: 23.2.91; Remove unwise advice from manual

[Reuben Thomas]

On 4 February 2011 23:57, Lennart Borgman <lennart.borgman@gmail.com> wrote:
> On Sat, Feb 5, 2011 at 12:26 AM, Reuben Thomas <rrt@sc3d.org> wrote:
>>
>>   Normally, well-designed Lisp programs should not use
>> `eval-after-load'.  If you need to examine and set the variables
>> defined in another library (those meant for outside use), you can do it
>> immediately--there is no need to wait until the library is loaded.  If
>> you need to call functions defined by that library, you should load the
>> library, preferably with `require' (*note Named Features::).
>
> You can't do that. Just imagine you write a library with one single
> purpose: doing something after another library is loaded.

I don't think that is at odds with the advice "Normally, well-designed
Lisp programs should not use `eval-after-load'." But if it is, then
the manual should be corrected.

However, that does not affect my suggestion that the advice about
writing code for "personal customizations" be removed.

-- 
http://rrt.sc3d.org

bug#7986: 23.2.91; Remove unwise advice from manual

[Chong Yidong]

Reuben Thomas <rrt@sc3d.org> writes:

>    But it is OK to use `eval-after-load' in your personal
> customizations if you don't feel that they must meet the design
> standards for programs meant for wider use.
>
> This sort of advice tends to be unwise to give, because people write
> code for their own use, then later distribute it and forget to clean it
> up.

Fair enough.  Removed.