Re: save-excursion again

[David Kastrup <dak@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> So, every time we want to please the byte compiler, we need to prove
>> a little theorem to the effect that the code X doesn't enter the
>> buffer A?  (No doubt some of these theorems will be obvious.)
>
> Indeed.  The problem being that the precise semantics of such a
> construction is pretty subtle, so the byte-compiler can't do the proof
> for you.  In some cases the proof is easy (e.g. there's no movement at
> all in that piece of code), but often it's very difficult (tho my
> experience might be made worse since I usually make such changes to
> code with which I'm not familiar).  My approach is to basically
> replace all such code with just `with-current-buffer', then let users
> find the counter examples.

I don't see how this process is supposed to terminate if users find
counterexamples.  Presumably the original code is then reinstated, and
the whole procedure starts from the beginning.  It would not appear that
there is a way to _intentionally_ use that construct without you
eventually replacing it.

-- 
David Kastrup