diff options
Diffstat (limited to 'lisp/emacs-lisp')
| -rw-r--r-- | lisp/emacs-lisp/eieio-core.el | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/lisp/emacs-lisp/eieio-core.el b/lisp/emacs-lisp/eieio-core.el index a82e887fa0c..e4221e48fe2 100644 --- a/lisp/emacs-lisp/eieio-core.el +++ b/lisp/emacs-lisp/eieio-core.el @@ -1227,6 +1227,8 @@ method invocation orders of the involved classes." (require 'cl-generic) +;;;; General support to dispatch based on the type of the argument. + (add-function :before-until cl-generic-tagcode-function #'eieio--generic-tagcode) (defun eieio--generic-tagcode (type name) @@ -1246,6 +1248,29 @@ method invocation orders of the involved classes." (mapcar #'eieio--class-symbol (eieio--class-precedence-list (symbol-value tag))))) +;;;; Dispatch for arguments which are classes. + +;; Since EIEIO does not support metaclasses, users can't easily use the +;; "dispatch on argument type" for class arguments. That's why EIEIO's +;; `defmethod' added the :static qualifier. For cl-generic, such a qualifier +;; would not make much sense (e.g. to which argument should it apply?). +;; Instead, we add a new "subclass" specializer. + +(add-function :before-until cl-generic-tagcode-function + #'eieio--generic-subclass-tagcode) +(defun eieio--generic-subclass-tagcode (type name) + (when (eq 'subclass (car-safe type)) + `(60 . (and (symbolp ,name) (eieio--class-v ,name))))) + +(add-function :before-until cl-generic-tag-types-function + #'eieio--generic-subclass-tag-types) +(defun eieio--generic-subclass-tag-types (tag) + (when (eieio--class-p tag) + (mapcar (lambda (class) + `(subclass + ,(if (symbolp class) class (eieio--class-symbol class)))) + (eieio--class-precedence-list tag)))) + ;;; Backward compatibility functions ;; To support .elc files compiled for older versions of EIEIO. |