Re: [PATCH] Improve find-sibling-rules option type

["Paul W. Rankin" via "Emacs development discussions." <emacs-devel@gnu.org>]

On 2023-09-24 19:44, Mauro Aranda wrote:
> In particular, AFAICT there could be more than one EXPANSION.  In that
> case, :value-type should be a repeat of strings, not just a string.  In
> addition, regexp should be used as the :key-type type.  (I see that
> Philip already spotted this)

Just looking at `find-sibling-file-search' and it looks like maybe? But 
if this is the case I think the docstring should be rewritten. Looking 
at it from a user's perspective if the docstring says "a string" but 
there's a repeat of strings, that would be confusing.

> In general, when converting from sexp to a more specific type, I think
> we have to take extra precaution and check the code for how the
> variable it's used (i.e., the docstring might not tell the whole 
> story).
> If ever in doubt, then it might be better and safer to offer a choice
> with the more specific type first, and keep sexp as a catch-all
> alternative.

Customize already provides for this! The user can click [State] > Show 
Saved Lisp Expression to edit/override the value with their own sexp.

I think the main thing is not to have user options that demand sexps.