Re: save-excursion again

[Uday S Reddy <u.s.reddy@cs.bham.ac.uk>]

On 6/25/2010 10:20 PM, Stefan Monnier wrote:
>> Which brings up a question for Stefan.  Are you saying that the
>> condition-case-save-point-and-mark aspect of `save-excursion' should
>> be abstracted out (say as `save-region') and separated from the
>> save-buffer aspect?
>
> Not sure what you mean.  If you mean we should introduce
> a save-excursion-but-not-buffer, then I think it's a bad idea, because
> such a thing would still have to save a marker (so there's no
> improvement in terms of the amount of data saved) and the semantics of
> "restore point in another buffer" is murky in Emacs.

I think the point is that save-excursion has been saving too much.  So, when we 
see a save-excursion in a piece of code, we are not sure whether it was meant 
to save the point and mark, or the current-buffer, or both.  It seems that the 
original developers were themselves unsure after a while.

I took Stephen's point as saying that, if we have separate save-current-buffer 
and save-region, with save-excursion strongly discouraged, we would promote a 
clearer programming style.

Cheers,
Uday