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Re: problems with Emacs 28


From: Emanuel Berg
Subject: Re: problems with Emacs 28
Date: Sun, 25 Oct 2020 00:08:03 +0200
User-agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux)

Drew Adams wrote:

>>> What is that bang (explication mark) syntax BTW?
>> 
>> That comes from the scheme tradition: it is used for functions that
>> modify something (state), unlike "pure" functions that "only"
>> calculate a return value. E.g. `+', `car' vs. `setcar!' etc., you
>> get it.
>
> FWIW, I think it's a mistake for Emacs to adopt that convention now,
> or at least it's a mistake to adopt it only partially.
>
> If users can't depend on it, to let them know if a function might
> modify data destructively, then it can mislead, and so be even more
> "dangerous". Now, we really need a giant sign saying that you can't
> rely on a destructive function's name having a suffix of `!'.
>
> Same thing for Scheme's `?' suffix, to indicate a predicate.
> Elisp uses the more traditional Lisp suffix of `p' for a predicate.
> Introducing `?' now, in only a partial way, wouldn't help, and it
> might confuse. Of course, that's trivial compared with the effect of
> possible confusion over destructive modification. (Yes, I know `?'
> hasn't been proposed as a suffix for predicates. Just sayin.)

Agree 100%. It makes the code disruptive to read and is slower to
type. The usefulness isn't obvious to me, either.


-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal




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