Re: Example use of macro to minimize and generalize the code

[Jean Louis <bugs@gnu.support>]

* Michael Heerdegen <michael_heerdegen@web.de> [2021-06-01 17:03]:
> Jean Louis <bugs@gnu.support> writes:
> 
> > (defmacro when-tabulated-id (table &rest body)
> >   (declare (indent 2) (debug t))
> >   ;;(ignore id)
> >   `(if id
> >        (progn
> > 	 ,@body)
> >      (if (or (eq ,table 'any)
> > 	     (string-equal ,table rcd-current-table))
> > 	 (let ((id (tabulated-list-get-id)))
> > 	   (if id
> > 	       (progn ,@body)
> > 	     (message "Did not get ID")))
> >        (message "This function is for table `%s' only" ,table))))
> 
> Yes, better.
> 
> The downside now is that using the macro hides the fact that the code
> depends on the id, and the resulting code is (still) hard to understand.
> Why don't you consider to make the id a real argument?

I wish I could fully understand but I don't, and I consider your
advises important.

How would I make the ID a real argument?

Each of those functions has &optional id as if function is not
capturing ID from tabulated-list-mode then it may receive it
programmatically.

Example:

(defun hyperscope-new-appointment (&optional id)
  "Add new `Appointment' hyperdocument."
  (interactive)
  (when-tabulated-id "hyobjects"
    (let ((parent (hlink-parent id)))
      (hyperscope-add-new-appointment-hyperdocument parent))))

-- 
Jean

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