Function: cl-decf

cl-decf is a macro defined in cl-lib.el.gz.

Signature

(cl-decf PLACE &optional X)

Documentation

Decrement PLACE by X (1 by default).

PLACE may be a symbol, or any generalized variable allowed by setf. The return value is the decremented value of PLACE.

If X is specified, it should be an expression that should evaluate to a number.

View in manual

Aliases

decf (obsolete since 27.1)

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/cl-lib.el.gz
(defmacro cl-decf (place &optional x)
  "Decrement PLACE by X (1 by default).
PLACE may be a symbol, or any generalized variable allowed by `setf'.
The return value is the decremented value of PLACE.

If X is specified, it should be an expression that should
evaluate to a number."
  (declare (debug cl-incf))
  (if (symbolp place)
      (list 'setq place (if x (list '- place x) (list '1- place)))
    (list 'cl-callf '- place (or x 1))))