;;; -*-lisp-*-
;;;
;;; Layout for instances and vtables
;;;
;;; (c) 2009 Straylight/Edgeware
;;;

;;;----- Licensing notice ---------------------------------------------------
;;;
;;; This file is part of the Simple Object Definition system.
;;;
;;; SOD is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2 of the License, or
;;; (at your option) any later version.
;;;
;;; SOD 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 General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with SOD; if not, write to the Free Software Foundation,
;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

(cl:in-package #:sod)

;;;--------------------------------------------------------------------------
;;; Effective slot objects.

(defclass effective-slot ()
  ((class :initarg :class :type sod-slot :reader effective-slot-class)
   (slot :initarg :slot :type sod-slot :reader effective-slot-direct-slot)
   (initializer :initarg :initializer :type (or sod-initializer null)
		:reader effective-slot-initializer))
  (:documentation
   "Describes a slot and how it's meant to be initialized.

   Effective slot objects are usually attached to layouts."))

(defgeneric find-slot-initializer (class slot)
  (:documentation
   "Return the most specific initializer for SLOT, starting from CLASS."))

(defgeneric compute-effective-slot (class slot)
  (:documentation
   "Construct an effective slot from the supplied direct slot.

   SLOT is a direct slot defined on CLASS or one of its superclasses.
   (Metaclass initializers are handled using a different mechanism.)"))

;;;--------------------------------------------------------------------------
;;; Instance layout objects.

(defclass islots ()
  ((class :initarg :class :type sod-class :reader islots-class)
   (subclass :initarg :subclass :type sod-class :reader islots-subclass)
   (slots :initarg :slots :type list :reader islots-slots))
  (:documentation
   "The collection of effective SLOTS defined by an instance of CLASS."))

;;; Standard implementation.

;;;--------------------------------------------------------------------------
;;; Effective methods.

;;;--------------------------------------------------------------------------
;;; Vtable layout.

;;; vtmsgs

;;; base-offset

;;; chain-offset

;;; vtable

;;; Implementation.

;;;----- That's all, folks --------------------------------------------------