Re: xref and leaving "temporary" buffers open

[Dmitry Gutov]

On 07/29/2015 02:48 AM, Stefan Monnier wrote:

> I can see something like this working:

Right. There were more specific proposals in this thread. You might want 
to comment on those.

> - set a buffer-local variable "buffer-file-incomplete" to a function
>    which performs the missing setup (e.g. set up VC status and stuff).
> - ignore buffers with this var set to a non-nil value in things like
>    buffer completion.

So, you'd limit the changes to the higher level, like 
read-buffer-to-switch and internal-complete-buffer-except?

What about other interfaces we have for buffer switching? 
ido-make-buffer-list-1 calls buffer-list (that one's easy to change, 
since it's in the core), iflipb calls buffer-list, helm-buffers-list 
calls buffer-list.

> - kill those buffers every once in a while.
>
> But I'm not sure the speed up will be ground breaking if we need to call
> `syntax-propertize' anyway.

As long as the buffer-file-incomplete function doesn't change the buffer 
contents, at least we won't have to call syntax-propertize multiple times.

And depending on the file size, the overhead from vc-find-file-hook may 
become noticeable, too. In (find-file-noselect ".gitignore"), it takes 
more than half of the time (15 out of 25 ms), here.