Use keywords instead of unbound symbols for slot options

[Ambrevar]

For instance in

(on-external-modification
    'ask
    :type (member ask reload overwrite)
    :documentation "Whether to reload or overwrite the file if it was modified
since it was last loaded.")

...

(export-always '(ask reload overwrite))

We export unbound symbols ask, reload and overwrite. This is not very good practice. Switching to keywords would be cleaner.

The only benefit of using symbols is that they allow for completion, but since they are not in a separate package anyways, it's unlikely that completion is ever going to be used.

Unfortunately this breaks backward compatibility. I suggest to release 2.0 then, since a new version is long due.

@aadcg @aartaka ?

[aartaka]

Yes, I'm all for keywords :D

New version is okay too!

[aadcg]

Good idea.

[Ambrevar]

So I suggest we first release 1.1.0 as per #13 (@aadcg will do it I think), then we can release 2.0.0.

[Ambrevar]

Actually I remember why I went with symbols: it's because I initially thoughts that restarts had to be non-keyword symbols. But that's not true, since this works:

(restart-case
     (let ((r (find-restart :my-restart)))
       (format t "~S is named ~S" r (restart-name r)))
   (:my-restart () nil))

So really no reason to keep these non-keyword symbols.

[aartaka]

As an alternative perspective, maybe we can add functions that mirror/invoke the given restart? The standard even has some functions like that (continue, abort). So we can retain those symbols and bind those to functions like that:

(defun ask (&optional condition)
  (invoke-restart (find-restart 'ask condition)))

[Ambrevar]

I like it!