Function: eieio--add-new-slot

eieio--add-new-slot is a byte-compiled function defined in eieio-core.el.gz.

Signature

(eieio--add-new-slot NEWC SLOT INIT ALLOC &optional DEFAULTOVERRIDE SKIPNIL)

Documentation

Add into NEWC attribute SLOT.

If a slot of that name already exists in NEWC, then do nothing. If it doesn't exist, INIT is the initarg, if any. Argument ALLOC specifies if the slot is allocated per instance, or per class. If optional DEFAULTOVERRIDE is non-nil, then if A exists in NEWC, we must override its value for a default. Optional argument SKIPNIL indicates if type checking should be skipped if default value is nil.

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/eieio-core.el.gz
(defun eieio--add-new-slot (newc slot init alloc
				 &optional defaultoverride skipnil)
  "Add into NEWC attribute SLOT.
If a slot of that name already exists in NEWC, then do nothing.
If it doesn't exist, INIT is the initarg, if any.
Argument ALLOC specifies if the slot is allocated per instance, or per class.
If optional DEFAULTOVERRIDE is non-nil, then if A exists in NEWC,
we must override its value for a default.
Optional argument SKIPNIL indicates if type checking should be skipped
if default value is nil."
  ;; Make sure we duplicate those items that are sequences.
  (let* ((a (cl--slot-descriptor-name slot))
         (d (cl--slot-descriptor-initform slot))
         (old (car (cl-member a (eieio--class-slots newc)
                              :key #'cl--slot-descriptor-name)))
         (cold (car (cl-member a (eieio--class-class-slots newc)
                               :key #'cl--slot-descriptor-name))))
    (cl-pushnew a eieio--known-slot-names)
    (when (eq alloc :class)
      (cl-pushnew a eieio--known-class-slot-names))
    (condition-case nil
        (if (sequencep d) (setq d (copy-sequence d)))
      ;; This copy can fail on a cons cell with a non-cons in the cdr.  Let's
      ;; skip it if it doesn't work.
      (error nil))
    ;; (if (sequencep type) (setq type (copy-sequence type)))
    ;; (if (sequencep cust) (setq cust (copy-sequence cust)))
    ;; (if (sequencep custg) (setq custg (copy-sequence custg)))

    ;; To prevent override information w/out specification of storage,
    ;; we need to do this little hack.
    (if cold (setq alloc :class))

    (if (memq alloc '(nil :instance))
        ;; In this case, we modify the INSTANCE version of a given slot.
        (progn
          ;; Only add this element if it is so-far unique
          (if (not old)
              (progn
                (eieio--perform-slot-validation-for-default slot skipnil)
                (push slot (eieio--class-slots newc))
                )
            ;; When defaultoverride is true, we are usually adding new local
            ;; attributes which must override the default value of any slot
            ;; passed in by one of the parent classes.
            (when defaultoverride
              (eieio--slot-override old slot skipnil)))
          (when init
            (cl-pushnew (cons init a) (eieio--class-initarg-tuples newc)
                        :test #'equal)))

      ;; CLASS ALLOCATED SLOTS
      (if (not cold)
          (progn
            (eieio--perform-slot-validation-for-default slot skipnil)
            ;; Here we have found a :class version of a slot.  This
            ;; requires a very different approach.
            (push slot (eieio--class-class-slots newc)))
        (when defaultoverride
          ;; There is a match, and we must override the old value.
          (eieio--slot-override cold slot skipnil))))))