Re: [O] [RFC] Change some defcustoms into defcont

[Sebastien Vauban]

Hello Nicolas,

Nicolas Goaziou wrote:
> I'd like to suggest changing the following defcustom variables into
> defconst:
>
>   - org-deadline-string
>   - org-scheduled-string
>   - org-closed-string
>   - org-clock-string
>   - org-comment-string
>   - org-quote-string
>   - org-effort-property
>   - org-archive-tag

At first, I thought: "I certainly have changed at least one of them" (such
`org-log-note-headings' for which I changed the `state' string to "State %-12S
-> %-12s %t" -- as I prefer the FROM -> TO presentation of state changes).

Though, FWIW, no, these are still the original values in my case as well.

> There's no fundamental reason to change these, as they belong to Org
> syntax, much like star character for headlines and ":END:" closing
> string for drawers.
>
> They can also introduce bugs in code when modified (e.g. modifying
> `org-effort-property' breaks `ox-taskjuggler'). Of course, this can be
> avoided with careful checks, but this puts an extra burden on developers
> for a tiny benefit for the user.
>
> Eventually, they can be costly, since changing any of them implies that
> cache in every Org buffer must be erased.
>
> Allowing customization is generally good, but I think Org syntax should
> never be a moving target.
>
> Note that this shouldn't introduce much backward incompatibility (unless
> user changes them through customize interface) since a defconst can
> still be setq'ed and variables will still be used in code base.

I thought that users never ever could change constants. But the docstring of
`defconst' indeed tells that "this constancy is not actually enforced by Emacs
Lisp". Though, can we be sure that this will stay true?

> Opinions?

OK for me.

Best regards,
  Seb

-- 
Sebastien Vauban