Re: Making a function than can only be used interactively

[Christopher Dimech <dimech@gmx.com>]

Jul 4, 2022, 19:40 by monnier@iro.umontreal.ca:

>>>        Only after byte-compile of a file?
>>>        So there is no way to actually make a function interactive only?


>    Please define what it is you mean by "make a function interactive only".

>    Do you mean that it should be illegal to write code that calls the
>    function directly, so whoever writes it can be sued?
>    Would it be acceptable for someone to just think about writing such code
>    as long as they don't actually write it?

>    More seriously, what are you trying to gain by "mak[ing] a function
>    interactive only"? Usually, the reason why one might want to make
>    a function "interactive only" is that code that calls this function is
>    probably incorrect and would likely be served better by some
>    other function.

I could envisage a situation where someone wants to concentrate on the
interactive parts, if taking care of non-interactive use would make the
function difficult to maintain.  I am not sure that it will always be
because of bad design.

>    So the purpose is to help people write better code.
>    For this reason the declaration only has an effect in terms of
>    byte-compiler warnings: those who don't bother to byte-compile their
>    code presumably don't care about the quality of their code anyway.

>    Emacs doesn't offer any pre-defined way to really enforce that
>    a function is only used interactively, and in large parts this is
>    because, as a matter of design principle, Emacs makes no effort to stop
>    people from shooting themselves in the foot (instead, it tries to make
>    it easier for people not to shoot themselves in the foot).

>    Stefan

I also say that it would be better to have declarations that are somewhat
safer for the general elisp user as well.