diff options
Diffstat (limited to 'lisp/emacs-lisp/cl-lib.el')
| -rw-r--r-- | lisp/emacs-lisp/cl-lib.el | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/lisp/emacs-lisp/cl-lib.el b/lisp/emacs-lisp/cl-lib.el index 8c4455a3dad..1f8615fad3e 100644 --- a/lisp/emacs-lisp/cl-lib.el +++ b/lisp/emacs-lisp/cl-lib.el @@ -639,6 +639,42 @@ If ALIST is non-nil, the new pairs are prepended to it." (require 'cl-macs) (require 'cl-seq)) +(defun cl--old-struct-type-of (orig-fun object) + (or (and (vectorp object) + (let ((tag (aref object 0))) + (when (and (symbolp tag) + (string-prefix-p "cl-struct-" (symbol-name tag))) + (unless (eq (symbol-function tag) + :quick-object-witness-check) + ;; Old-style old-style struct: + ;; Convert to new-style old-style struct! + (let* ((type (intern (substring (symbol-name tag) + (length "cl-struct-")))) + (class (cl--struct-get-class type))) + ;; If the `cl-defstruct' was recompiled after the code + ;; which constructed `object', `cl--struct-get-class' may + ;; not have called `cl-struct-define' and setup the tag + ;; symbol for us. + (unless (eq (symbol-function tag) + :quick-object-witness-check) + (set tag class) + (fset tag :quick-object-witness-check)))) + (cl--class-name (symbol-value tag))))) + (funcall orig-fun object))) + +;;;###autoload +(define-minor-mode cl-old-struct-compat-mode + "Enable backward compatibility with old-style structs. +This can be needed when using code byte-compiled using the old +macro-expansion of `cl-defstruct' that used vectors objects instead +of record objects." + :global t + (cond + (cl-old-struct-compat-mode + (advice-add 'type-of :around #'cl--old-struct-type-of)) + (t + (advice-remove 'type-of #'cl--old-struct-type-of)))) + ;; Local variables: ;; byte-compile-dynamic: t ;; End: |