Re: How to warn about obsolete file in ELPA package

[Stefan Monnier]

>>> We would like to emit an obsoletion warning when dash-functional.el is
>>> used, similar to the one for lisp/obsolete/* libraries.
>> I think you can get exactly this behavior by placing the file in
>> a directory called `obsolete`.
> Could we add something like (cl-declaim obsolete) to make this independent of 
> the filename?

You can probably cook something up using `macroexp--warn-and-return`.
E.g. something like:

    (defmacro my-\, (exp) (eval exp t))
    (my-\,
     (when (fboundp 'macroexp--warn-and-return) ;; New in Emacs-24.3
       (macroexp--warn-and-return
        "dash-functions is obsolete, just require dash instead" nil)))


-- Stefan