RE: problems with Emacs 28

[Drew Adams]

> > 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 `!'.
> 
> BTW, we use "destructive" most of the time to denote "might do anything
> with the original value" (from "destroy).  Vs. here the ! means
> "modifies in place" (you can rely on the value being present in the
> original place).

Yes.  In general it means that the "function"
might modify data (in particular input data).

Most important here is "modify".  Second most
important is "might".

"Destructive" can be misleading, since if you
intend the modification then, well, it's doing
what you want and expect.