Function: register--jumpable-p

register--jumpable-p is a byte-compiled function defined in register.el.gz.

Signature

(register--jumpable-p REGVAL)

Documentation

Return non-nil if register-val-insert is implemented for REGVAL.

Source Code

;; Defined in /usr/src/emacs/lisp/register.el.gz
(defun register--jumpable-p (regval)
  "Return non-nil if `register-val-insert' is implemented for REGVAL."
  (pcase (register--get-method-type regval 'register-val-jump-to '(t))
    ;; The only applicable method is one with the `t' specializer,
    ;; i.e. the default method which signals an error.
    ('t nil)
    ;; The best applicable method is that for `registerv' objects
    ;; which works only if there's a function in `registerv-jump-func'.
    ('registerv (registerv-jump-func regval))
    ;; The best applicable method is the one below for register values of
    ;; type `cons' so return non-nil for those values supported by that method.
    ('cons
     (or (frame-configuration-p (car regval))
	 (window-configuration-p (car regval))
	 (memq (car regval) '(file buffer file-query))))
    ;; There's another method that handles VAL.
    ;; Presumably its presence implies that we can "jump" to that value.
    (type type)))