bug#67045: No way to control location of .aspell.en.prepl from within Emacs

[Stefan Kangas <stefankangas@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

> Why do you consider it not a user-friendly solution?  There's no limit
> to command-line options a speller can have, so it is not reasonable
> IMO to expect Emacs to have a separate variable for each one of them.
> Thus, our solution to have a single variable that can hold any
> additional options is a reasonable compromise.
[...]
> Stefan, WDYT?

I could go either way with this one, to be really honest.  Eli is right
that proliferating our user options with all the details of concrete
spell checkers will start getting unwieldy at some point.

Personally, I'd rather see the interface of ispell.el get more
abstracted away from concrete spell checkers.  I don't think users of
Emacs shouldn't have to mess with aspell/ispell/hunspell/enchant (unless
they want to, of course).

So I'm not entirely sure that adding a new user option like this is
moving things in the right thing direction.