| 1 | ;;; -*-lisp-*- |
| 2 | ;;; |
| 3 | ;;; Class finalization protocol |
| 4 | ;;; |
| 5 | ;;; (c) 2009 Straylight/Edgeware |
| 6 | ;;; |
| 7 | |
| 8 | ;;;----- Licensing notice --------------------------------------------------- |
| 9 | ;;; |
| 10 | ;;; This file is part of the Sensible Object Design, an object system for C. |
| 11 | ;;; |
| 12 | ;;; SOD is free software; you can redistribute it and/or modify |
| 13 | ;;; it under the terms of the GNU General Public License as published by |
| 14 | ;;; the Free Software Foundation; either version 2 of the License, or |
| 15 | ;;; (at your option) any later version. |
| 16 | ;;; |
| 17 | ;;; SOD is distributed in the hope that it will be useful, |
| 18 | ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ;;; GNU General Public License for more details. |
| 21 | ;;; |
| 22 | ;;; You should have received a copy of the GNU General Public License |
| 23 | ;;; along with SOD; if not, write to the Free Software Foundation, |
| 24 | ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | |
| 26 | (cl:in-package #:sod) |
| 27 | |
| 28 | ;;;-------------------------------------------------------------------------- |
| 29 | ;;; Protocol definition. |
| 30 | |
| 31 | (export 'compute-cpl) |
| 32 | (defgeneric compute-cpl (class) |
| 33 | (:documentation |
| 34 | "Returns the class precedence list for CLASS.")) |
| 35 | |
| 36 | (export 'compute-chains) |
| 37 | (defgeneric compute-chains (class) |
| 38 | (:documentation |
| 39 | "Compute the layout chains for CLASS. |
| 40 | |
| 41 | Returns the following three values. |
| 42 | |
| 43 | * the head of the class's primary chain; |
| 44 | |
| 45 | * the class's primary chain as a list, most- to least-specific; and |
| 46 | |
| 47 | * the complete collection of chains, as a list of lists, each most- to |
| 48 | least-specific, with the primary chain first. |
| 49 | |
| 50 | These values will be stored in the CHAIN-HEAD, CHAIN and CHAINS slots. |
| 51 | |
| 52 | If the chains are ill-formed (i.e., not distinct) then an error is |
| 53 | signalled.")) |
| 54 | |
| 55 | (export 'guess-metaclass) |
| 56 | (defgeneric guess-metaclass (class) |
| 57 | (:documentation |
| 58 | "Determine a suitable metaclass for the CLASS. |
| 59 | |
| 60 | The default behaviour is to choose the most specific metaclass of any of |
| 61 | the direct superclasses of CLASS, or to signal an error if that failed.")) |
| 62 | |
| 63 | (export 'check-sod-class) |
| 64 | (defgeneric check-sod-class (class) |
| 65 | (:documentation |
| 66 | "Check the CLASS for validity. |
| 67 | |
| 68 | This is done as part of class finalization. The checks performed are as |
| 69 | follows. |
| 70 | |
| 71 | * The class name and nickname, and the names of messages, obey the |
| 72 | rules (see VALID-NAME-P). |
| 73 | |
| 74 | * The messages and slots have distinct names. |
| 75 | |
| 76 | * The classes in the class-precedence-list have distinct nicknames. |
| 77 | |
| 78 | * The chain-link is actually a proper (though not necessarily direct) |
| 79 | superclass. |
| 80 | |
| 81 | * The chosen metaclass is actually a subclass of all of the |
| 82 | superclasses' metaclasses. |
| 83 | |
| 84 | Returns true if all is well; false (and signals errors) if anything was |
| 85 | wrong.")) |
| 86 | |
| 87 | (export 'finalize-sod-class) |
| 88 | (defgeneric finalize-sod-class (class) |
| 89 | (:documentation |
| 90 | "Computes all of the gory details about a class. |
| 91 | |
| 92 | Once one has stopped inserting methods and slots and so on into a class, |
| 93 | one needs to finalize it to determine the layout structure and the class |
| 94 | precedence list and so on. More precisely that gets done is this: |
| 95 | |
| 96 | * Related classes (i.e., direct superclasses and the metaclass) are |
| 97 | finalized if they haven't been already. |
| 98 | |
| 99 | * If you've been naughty and failed to store a list of slots or |
| 100 | whatever, then an empty list is inserted. |
| 101 | |
| 102 | * The class precedence list is computed and stored. |
| 103 | |
| 104 | * The class is checked for compiance with the well-formedness rules. |
| 105 | |
| 106 | * The layout chains are computed.")) |
| 107 | |
| 108 | ;;;----- That's all, folks -------------------------------------------------- |