bug#20420: 25.0.50; eieio methods with optional arguments now fail

[Vitalie Spinu <spinuvit@gmail.com>]

 >>> Stefan Monnier on Sat, 25 Apr 2015 10:41:40 -0400 wrote:


 > That tells me *how* you used it, not *where*.

I was using it in polymode package for a generic indentation
functionality:

  https://github.com/vspinu/polymode/blob/master/polymode-methods.el#L530

 >> As we are on this topic how about allowing for implicit dispatch on the
 >> arbitrary context? I mean something along the following lines:

 > Quoting from cl-generic.el:

 >    ;; TODO:
 >    [...]
 >    ;; - A way to dispatch on the context (e.g. the major-mode, some global
 >    ;;   variable, you name it).
 >    [...]
 >    ;;; Just for kicks: dispatch on major-mode
 >    ;;
 >    ;; Here's how you'd use it:
 >    ;;   (cl-defmethod foo ((x (major-mode text-mode)) y z) ...)
 >    ;; And then
 >    ;;     (foo 'major-mode toto titi)
 >    ;;
 >    ;; FIXME: Better would be to do that via dispatch on an "implicit argument".
 >    ;; E.g. (cl-defmethod foo (y z &context (major-mode text-mode)) ...)

Aha. Cool! I will have a look. Is there a more elaborate documentation
somewhere? Particularly I don't see "specializer" and "generalizer"
being properly defined anywhere.


  Vitalie