Re: etags.el tags-search use global syntax table

[Francesco Potorti` <pot@gnu.org>]

>    +The optional argument KEEP-IF-CLASS is a list of symbols. If the
>    +major mode has any of these symbols in its mode-class property, or if
>    +one the symbols in the list is t, we do not set the major mode."
>
>I am not sure what that means.  Does it mean that if I pass (t foo)
>for KEEP-IF-CLASS, then set-auto-mode will certainly not set the major
>mode?

Yes.

>That is what the words seem to say -- but it doesn't seem useful.
>What's the point of calling set-auto-mode and never setting the major mode?

Those three lines were meant to present the gist of the change, that is,
an abstract of the following patch.  But I made another change, that is,
the patched set-auto-mode returns the chosen mode.  I think this may be
useful for programs that want to know which mode a buffer should be in,
but do not want to set it.

>Also, if you want a way to do that, why make the signal be a list
>containing t?  Why not just pass t as the argument?  Why make it a
>list if the rest of the list is irrelevant?

Yes, passing just t would certainly be clearer.  I thought that having
always a list would be simpler to use and possibly more flexible, but I
would certainly make that change if you think it is best.

>One other question.  Since set-auto-mode doesn't look at mode: local
>bindings, is it sufficient?

Well, no, it is not.  I had overlooked that problem, thanks.

>Aside from that, it looks good.  Next question is how fast it runs.

When I manage to find some more time, I'll look into the mode: local
bindings and do some speed tests.