;;; -*-lisp-*-
;;;
;;; Class finalization protocol
;;;
;;; (c) 2009 Straylight/Edgeware
;;;

;;;----- Licensing notice ---------------------------------------------------
;;;
;;; This file is part of the Sensble Object Design, an object system for C.
;;;
;;; 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)

;;;--------------------------------------------------------------------------
;;; Protocol definition.

(defgeneric compute-cpl (class)
  (:documentation
   "Returns the class precedence list for CLASS."))

(defgeneric compute-chains (class)
  (:documentation
   "Compute the layout chains for CLASS.

   Returns the following three values.

     * the head of the class's primary chain;

     * the class's primary chain as a list, most- to least-specific; and

     * the complete collection of chains, as a list of lists, each most- to
       least-specific, with the primary chain first.

   These values will be stored in the CHAIN-HEAD, CHAIN and CHAINS slots.

   If the chains are ill-formed (i.e., not distinct) then an error is
   signalled."))

(defgeneric check-sod-class (class)
  (:documentation
   "Check the CLASS for validity.

   This is done as part of class finalization.  The checks performed are as
   follows.

     * The class name and nickname, and the names of messages, obey the
       rules (see VALID-NAME-P).

     * The messages and slots have distinct names.

     * The classes in the class-precedence-list have distinct nicknames.

     * The chain-link is actually a proper (though not necessarily direct)
       superclass.

     * The chosen metaclass is actually a subclass of all of the
       superclasses' metaclasses.

   Returns true if all is well; false (and signals errors) if anything was
   wrong."))

(defgeneric finalize-sod-class (class)
  (:documentation
   "Computes all of the gory details about a class.

   Once one has stopped inserting methods and slots and so on into a class,
   one needs to finalize it to determine the layout structure and the class
   precedence list and so on.  More precisely that gets done is this:

     * Related classes (i.e., direct superclasses and the metaclass) are
       finalized if they haven't been already.

     * If you've been naughty and failed to store a list of slots or
       whatever, then an empty list is inserted.

     * The class precedence list is computed and stored.

     * The class is checked for compiance with the well-formedness rules.

     * The layout chains are computed."))

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