Re: New function `emacs-version>='

[Juanma Barranquero <lektu@terra.es>]

On Sat, 3 May 2003 14:12:09 +0300, "Ehud Karni" <ehud@unix.mvs.co.il> wrote:

> > And, as a last resort, you can often do something like
> > 
> >   (unless (ignore-errors XXXX)
> >     YYYY)
> 
> That is NOT always possible

Yeah, well, that's perhaps the reason I wrote "you can *often* do..." :-)

But, honestly, how many cases like this one have you found?

> I have another actual example:
> How do you check that `perform-replace' accept a function in its
> REPLACEMENTS argument (id does in 21.x, does not in 20.x or lower) ?

OK, how do you check that if Emacs does not include emacs-version>= and
will not till 21.4, at the very least? What I mean is that Emacs does
*not* have the function, so you'll be stuck with custom-made checks for
a long time, unless you (as a module author, I mean) are going to drop
support for 21.3- releases. Any answer to the situation is forward
looking, and for that, it's better to be sure any such new change and/or
feature can be properly detected. It's more robust.

OTOH, the use of a function as REPLACEMENTS is not even documented, and
the docstring for `perform-replace' suggests not using the function, so
it's not a very compelling example IMO.

                                                           /L/e/k/t/u