Re: *scratch* buffer documentation

[Jean-Christophe Helary]

> On Dec 25, 2019, at 23:55, Eli Zaretskii <address@hidden> wrote:
> 
>> From: Jean-Christophe Helary <address@hidden>
>> Date: Wed, 25 Dec 2019 08:58:45 +0900
>> 
>> I am not seeing anything in the Emacs manual that says a modified *scratch* 
>> buffer does not trigger a "buffer modified. Kill anyway ?" message when 
>> quitting.
> 
> This is a standard Emacs behavior with any buffer that doesn't visit a
> file, so I'm not sure why you expected to see anything special in this
> case.

Interesting. I've used emacs on and off for more than 20 years, and much more 
in the last few years, and I was never aware of that. I always thought it was a 
property of the *scratch* buffer. I guess it's because I was mostly using 
buffer from files or saving new buffers to files.

So, I just checked the documentation (emacs manual) and here is what I found:

19 Using Multiple Buffers

→ nothing about that default behavior

19.1 Creating and Selecting Buffers

→ nothing about that default behavior

19.4 Killing Buffers

Buried at the bottom of the info about C-x k:

"If you ask to kill a file-visiting buffer that is modified, then you must 
confirm with ‘yes’ before the buffer is killed."

If that is how/where the default behavior is specified, maybe it ought to be in 
a more preeminent location.

also, on the same page:

" The command ‘M-x clean-buffer-list’ is a convenient way to purge them; it 
kills all the unmodified buffers that you have not used for a long time."

which kind of suggests that modified buffers would not be killed and thus 
contradict the above "default".

And that's it, as far as I can tell. No other part of the Buffer chapter give 
relevant information about what would happen to modified/unmodified buffers 
that are killed. Maybe the information is located some place else, but then we 
need to worry about how that information about buffers would be discovered 
there.

It seems to me that a default behavior should be very clearly defined very 
early in the manual. Buffers are a huge part of Emacs (and a huge difference 
with other text editors, that basically expect a user facing "buffer" to be 
saved after modification) and user have a strong expectation that user modified 
data is safe and warning will be issued when that data is at risks (in most 
reasonable cases).

So, would it be possible to have a strong clarification about the default 
behavior and ephemeral quality of the buffers in the opening paragraphs of "19 
Using Multiple Buffers" ? That would be tremendously helpful.

Or am I still missing something ?

JC


>>> Isn't that manifestly implicit on the first line of *scratch* ? :
>>> 
>>> ;; This buffer is for text that is not saved
>> 
>> No, because it is possible to save the buffer to a file. Also, the value of 
>> this text can be changed, so there is no guarantee that the user sees it.
> 
> Let's clarify the "is not saved" part of the text that is in the
> buffer, it's much more efficient than any documentation anywhere.
> 
> If that text is changed, whoever changes it is expected to know what
> he or she is doing, so let's not argue about that use case.
> 
> Thanks.
> 

Jean-Christophe Helary
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http://mac4translators.blogspot.com @brandelune