(interactive-form): New function.

1 files changed, 21 insertions, 19 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index eb55b416a92..eb476c65753 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1449,25 +1449,27 @@ configuration."
       (eq (car-safe object) 'lambda)
       (and (symbolp object) (fboundp object))))
 
-;; now in fns.c
-;(defun nth (n list)
-;  "Returns the Nth element of LIST.
-;N counts from zero.  If LIST is not that long, nil is returned."
-;  (car (nthcdr n list)))
-;
-;(defun copy-alist (alist)
-;  "Return a copy of ALIST.
-;This is a new alist which represents the same mapping
-;from objects to objects, but does not share the alist structure with ALIST.
-;The objects mapped (cars and cdrs of elements of the alist)
-;are shared, however."
-;  (setq alist (copy-sequence alist))
-;  (let ((tail alist))
-;    (while tail
-;      (if (consp (car tail))
-;         (setcar tail (cons (car (car tail)) (cdr (car tail)))))
-;      (setq tail (cdr tail))))
-;  alist)
+(defun interactive-form (function)
+  "Return the interactive form of FUNCTION.
+If function is a command (see `commandp'), value is a list of the form
+\(interactive SPEC).  If function is not a command,return nil."
+  (setq function (indirect-function function))
+  (when (commandp function)
+    (cond ((byte-code-function-p function)
+           (when (> (length function) 5)
+             (let ((spec (aref function 5)))
+               (if spec
+                   (list 'interactive spec)
+                 (list 'interactive)))))
+          ((subrp function)
+           (subr-interactive-form function))
+          ((eq (car-safe function) 'lambda)
+           (setq function (cddr function))
+           (when (stringp (car function))
+             (setq function (cdr function)))
+           (let ((form (car function)))
+             (when (eq (car-safe form 'interactive))
+               (copy-sequence form)))))))
 
 (defun assq-delete-all (key alist)
   "Delete from ALIST all elements whose car is KEY.