setf-star.lisp

;;; -*- Mode: Lisp; Package: CLIM-INTERNALS -*-

;;;  (c) copyright 2001 by 
;;;           Tim Moore (moore@bricoworks.com)

;;; This library is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU Library General Public
;;; License as published by the Free Software Foundation; either
;;; version 2 of the License, or (at your option) any later version.
;;;
;;; This library is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;; Library General Public License for more details.
;;;
;;; You should have received a copy of the GNU Library General Public
;;; License along with this library; if not, write to the 
;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, 
;;; Boston, MA  02111-1307  USA.

(in-package :clim-internals)

(defun setf-name-p (name)
  (and (listp name) (eq (car name) 'setf)))

;;; Many implementations complain if a defsetf definition and a setf function
;;; exist for the same place. Time to stop fighting that...

(defun make-setf*-gfn-name (function-name)
  (let* ((name-sym (cadr function-name)))
    `(setf ,(intern (format nil ".~A-~A."
			    (symbol-name name-sym)
			    (symbol-name '#:star))
		    (symbol-package name-sym)))))

(defmacro defgeneric* (fun-name lambda-list &body options)
  "Defines a SETF* generic function.  FUN-NAME is a SETF function
name.  The last argument is the single argument to the function in a
SETF place form; the other arguments are values collected from the
SETF new value form."
  (unless (setf-name-p fun-name)
    (error "~S is not a valid name for a SETF* generic function." fun-name))
  (let ((setf-name (cadr fun-name))
	(args (butlast lambda-list))
	(place (car (last lambda-list)))
	(gf (make-setf*-gfn-name fun-name)))
    `(progn
       (defsetf ,setf-name (,place) ,args
	 `(funcall #',',gf ,,@args ,,place))
       (defgeneric ,gf ,lambda-list ,@options))))

(defmacro defmethod* (name &body body)
  "Defines a SETF* method.  NAME is a SETF function name.  Otherwise,
like DEFMETHOD except there must exist a corresponding DEFGENERIC* form."
  (unless (setf-name-p name)
    (error "~S is not a valid name for a SETF* generic function." name))
  `(defmethod ,(make-setf*-gfn-name name) ,@body))