Re: scratch/accurate-warning-pos: Solid progress: the branch now bootstraps.

[Paul Eggert <eggert@cs.ucla.edu>]

On 11/29/18 2:05 PM, Alan Mackenzie wrote:
> We're not
> talking about macros generating messages for invalid input.  we're
> talking about generating message positions for the source being
> compiled.

I'm not sure what you mean here. The point of this exercise, as I 
understand it, is to generate better diagnostics for Lisp code that has 
problems in it (or is "invalid input" in some sense). Such code may 
define macros, and it may use those macros or may use macros defined 
elsewhere. If you're saying that we should talk only about problems in 
the part of the code that uses macros, and not about problems in the 
part of the code that defines macros, then that sounds like a 
conversation that would be too narrow.

>
>> I'm afraid we'll have to disagree here, as I can see examples where
>> symbols-with-pos fails ....
> I can't.  Please give an example, so I can see what you're talking about.

I attempted to give one in 
<https://lists.gnu.org/r/emacs-devel/2018-11/msg00530.html>, but you 
dismissed it as not relevant to the discussion. As mentioned above, I 
don't see why it's irrelevant.


> Symbols-with-pos exists, works, and works well.
> Conses-with-pos doesn't exist, hence doesn't work.  I doubt it can work.
> Can you create it?

I think I could, with time. I hope someone else will do it, though, as 
the problem does not seem that urgent. I would suggest that whoever does 
it, looks into Stefan's ideas in this area, e.g., 
<https://lists.gnu.org/r/emacs-devel/2018-11/msg00532.html>.

> is the idea of the two instances of code
> still live?
It's live only in the sense that it's better than 
scratch/accurate-warning-pos because of performance issues. I'd rather 
that we did something better than either.