Re: Proposal: move write-contents-functions higher up in basic-save-buffer

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Eric Abrahamsen <eric@ericabrahamsen.net>
>> Date: Wed, 24 May 2017 07:09:07 +0800
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> >> From: Eric Abrahamsen <eric@ericabrahamsen.net>
>> >> Date: Tue, 23 May 2017 15:19:11 +0800
>> >> 
>> >> Most special-mode buffers aren't visiting a file, and thus they miss out
>> >> on all the `do-auto-save' and `save-some-buffers' mechanisms. I'd guess
>> >> a fair number of packages that use special-mode *do* have some concept
>> >> of saving, or persisting data in some other way.
>> >> 
>> >> I think the `write-contents-functions' hook would be an ideal way of
>> >> solving this problem, except that the way `basic-save-buffer' is
>> >> written, it won't let you get that far without having a file name.
>> >> 
>> >> My proposal is to declare `write-contents-functions' as *explicitly* a
>> >> hook for buffers that don't have any file associated with them at all
>> >> (this would be in contrast to `write-file-functions'). Then we'd move it
>> >> up higher in the process: either earlier in `basic-save-buffer', or all
>> >> the way up to `save-buffer' -- that way `basic-save-buffer' could only
>> >> be for buffers that have a file.
>> >
>> > Did you investigate the alternative -- teach basic-save-buffer to save
>> > buffers that don't visit files?  If that's possible, it should be
>> > easier.
>> 
>> I thought that's what I was doing!
>
> I was referring specifically to this party of your description:
>
>> I think the `write-contents-functions' hook would be an ideal way of
>> solving this problem, except that the way `basic-save-buffer' is
>> written, it won't let you get that far without having a file name.
>
> My thinking was that by somehow overcoming this obstacle, you can
> allow users to easily use write-contents-functions as they need.
>
> Does this make sense?  If not, can you tell what is the difficulty in
> this regard?

I probably just did a poor job writing the initial message. That's what
I was proposing to begin with: to jiggle `basic-save-buffer' (and I
think also `save-some-buffers') so that the running of
`write-contents-functions' comes earlier in the function, or is
otherwise in its own branch that doesn't require a `buffer-file-name'. I
think it would be a fairly unintrusive change, it would just require a
bit of thought. I can try to produce a patch, if this is acceptable in
principle.

Eric