Re: Thoughts on getting correct line numbers in the byte compiler's warning messages

[Alan Mackenzie]

Hello, Stefan.

On Mon, Nov 12, 2018 at 15:36:14 -0500, Stefan Monnier wrote:
> > Unfortunately, this isn't going to work.  There will be macros which do
> > things like:
> >
> >     (cond ((eq (car form) 'bar) ....) .....)
> >
> > Here, (car form) is going to be #<symbol bar at 42>, so the eq is going
> > to return nil.
> [...]
> > This isn't pretty.  If this modification of eq, memq, .... is too much
> > to take, then I think the current approach is doomed to failure.

> It's indeed a serious concern.  Maybe we can circumvent by changing
> those pieces of code to use `eql` (and make sure `eql` consider
> a symbol and its symbol-with-pos as equal, obviously).

We can't change those bits of code - they're in macros that we don't
necessarily control.  Or are you suggesting that we somehow compile
macros such that `eq' gets replaced by `eql' in the critical places?

> Changing `eq` would better be avoided,

I agree, but don't see how we can avoid it.

Apologies for my earlier insistence that the approach would have little
impact outside the byte compiler.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).