Re: save-excursion and the mark

[Andreas Röhler]

Hi Stefan,

Am 14.04.2015 um 22:16 schrieb Stefan Monnier:
> > If you are indeed going forward with this change (why is that?),
> There are various problems with the previous save-excursion semantics,
> all linked to the mark-saving part of it, and this part is useless in
> 98% of the cases, useful in 1%, and harmful in 1%, so it's better to get
> rid of it in my view.
>
> Among the various problems, I actually fixed some recently (before
> throwing out the code), but the remaining ones are ugly:
> saving/restoring the mark includes saving/restoring the mark-active
> state as well, and in the general case you'd also want to run the
> (de)activate-mark-hook, which could break even more uses of
> save-excursion which never expected it to run such hook code.

Understand the wish to simplify things in this context.

AFAIU there is some redundancy - what about deprecating explicit setting 
of mark-active?

Its documentation says:
Non-nil means the mark and region are currently active in this buffer.

Maybe conceive region-active-p just as non-nil extend between point and 
mark - returning nil in case a mark is  not set?

Andreas




> > then maybe we could get a save-mark function?
> Since you're the only user so far, better write explicitly the exact
> saving/restoring you need (especially since it's not obvious to me what
> it is you really need, I guess you could start with something along the
> lines of (cl-letf (((mark)) (mark-active mark-active)) ...)).
>
>
>          Stefan