3 ;;; Class construction protocol
5 ;;; (c) 2009 Straylight/Edgeware
8 ;;;----- Licensing notice ---------------------------------------------------
10 ;;; This file is part of the Sensible Object Design, an object system for C.
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.
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.
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.
28 ;;;--------------------------------------------------------------------------
31 (export 'make-sod-class)
32 (defun make-sod-class (name superclasses pset &optional location)
33 "Construct and return a new SOD class with the given NAME and SUPERCLASSES.
35 This is the main constructor function for classes. The protocol works as
36 follows. The `:lisp-metaclass' property in PSET is checked: if it exists,
37 it must be a symbol naming a (CLOS) class, which is used in place of
38 `sod-class'. All of the arguments are then passed to `make-instance';
39 further behaviour is left to the standard CLOS instance construction
40 protocol; for example, `sod-class' defines an `:after'-method on
43 Minimal sanity checking is done during class construction; most of it is
44 left for `finalize-sod-class' to do (via `check-sod-class')."
46 (with-default-error-location (location)
47 (let* ((pset (property-set pset))
48 (best-class (or (get-property pset :lisp-metaclass :symbol nil)
50 (maximum (mapcar #'class-of superclasses)
52 (format nil "Lisp metaclass for ~A"
55 (class (make-instance best-class
57 :superclasses superclasses
58 :location (file-location location)
62 ;;;--------------------------------------------------------------------------
63 ;;; Slots and slot initializers.
65 (export 'make-sod-slot)
66 (defgeneric make-sod-slot (class name type pset &optional location)
68 "Construct, add, and attach a new slot with given NAME and TYPE, to CLASS.
70 This is the main constructor function for slots. This is a generic
71 function primarily so that the CLASS can intervene in the construction
72 process. The default method uses the `:slot-class' property (defaulting
73 to `sod-slot') to choose a (CLOS) class to instantiate. The slot is then
74 constructed by `make-instance' passing the arguments as initargs; further
75 behaviour is left to the standard CLOS instance construction protocol; for
76 example, `sod-slot' defines an `:after'-method on `shared-initialize'."))
78 (export 'make-sod-instance-initializer)
79 (defgeneric make-sod-instance-initializer
80 (class nick name value-kind value-form pset &optional location)
82 "Construct and attach an instance slot initializer, to CLASS.
84 This is the main constructor function for instance initializers. This is
85 a generic function primarily so that the CLASS can intervene in the
86 construction process. The default method looks up the slot using
87 `find-instance-slot-by-name', calls `make-sod-initializer-using-slot' to
88 actually make the initializer object, and adds it to the appropriate list
91 (export 'make-sod-class-initializer)
92 (defgeneric make-sod-class-initializer
93 (class nick name value-kind value-form pset &optional location)
95 "Construct and attach a class slot initializer, to CLASS.
97 This is the main constructor function for class initializers. This is a
98 generic function primarily so that the CLASS can intervene in the
99 construction process. The default method looks up the slot using
100 `find-class-slot-by-name', calls `make-sod-initializer-using-slot' to
101 actually make the initializer object, and adds it to the appropriate list
104 (export 'make-sod-initializer-using-slot)
105 (defgeneric make-sod-initializer-using-slot
106 (class slot init-class value-kind value-form pset location)
108 "Common construction protocol for slot initializers.
110 This generic function does the common work for constructing instance and
111 class initializers. It can usefully be specialized according to both the
112 class and slot types. The default method uses the `:initializer-class'
113 property (defaulting to INIT-CLASS) to choose a (CLOS) class to
114 instantiate. The slot is then constructed by `make-instance' passing the
115 arguments as initargs; further behaviour is left to the standard CLOS
116 instance construction protocol; for example, `sod-initializer' defines an
117 `:after'-method on `shared-initialize'.
119 Diagnosing unused properties is left for the caller (usually
120 `make-sod-instance-initializer' or `make-sod-class-initializer') to do.
121 The caller is also expected to have set `with-default-error-location' if
124 You are not expected to call this generic function directly; it's more
125 useful as a place to hang methods for custom initializer classes."))
127 ;;;--------------------------------------------------------------------------
128 ;;; Messages and methods.
130 (export 'make-sod-message)
131 (defgeneric make-sod-message (class name type pset &optional location)
133 "Construct and attach a new message with given NAME and TYPE, to CLASS.
135 This is the main constructor function for messages. This is a generic
136 function primarily so that the CLASS can intervene in the construction
137 process. The default method uses the `:message-class' property to choose
138 a (CLOS) class to instantiate; if no such property is provided but a
139 `combination' property is present, then `aggregating-message' is chosen;
140 otherwise `standard-message' is used. The message is then constructed by
141 `make-instance' passing the arguments as initargs; further behaviour is
142 left to the standard CLOS instance construction protocol; for example,
143 `sod-message' defines an `:after'-method on `shared-initialize'."))
145 (export 'make-sod-method)
146 (defgeneric make-sod-method
147 (class nick name type body pset &optional location)
149 "Construct and attach a new method to CLASS.
151 This is the main constructor function for methods. This is a generic
152 function primarily so that the CLASS can intervene in the message lookup
153 process, though this is actually a fairly unlikely occurrence.
155 The default method looks up the message using `find-message-by-name',
156 invokes `make-sod-method-using-message' to make the method object, and
157 then adds the method to the class's list of methods. This split allows
158 the message class to intervene in the class selection process, for
161 (export 'make-sod-method-using-message)
162 (defgeneric make-sod-method-using-message
163 (message class type body pset location)
165 "Main construction subroutine for method construction.
167 This is a generic function so that it can be specialized according to both
168 a class and -- more particularly -- a message. The default method uses
169 the `:method-class' property (defaulting to the result of calling
170 `sod-message-method-class') to choose a (CLOS) class to instantiate. The
171 method is then constructed by `make-instance' passing the arguments as
172 initargs; further behaviour is left to the standard CLOS instance
173 construction protocol; for example, `sod-method' defines an
174 `:after'-method on `shared-initialize'.
176 Diagnosing unused properties is left for the caller (usually
177 `make-sod-method') to do. The caller is also expected to have set
178 `with-default-error-location' if appropriate.
180 You are not expected to call this generic function directly; it's more
181 useful as a place to hang methods for custom method classes."))
183 (export 'sod-message-method-class)
184 (defgeneric sod-message-method-class (message class pset)
186 "Return the preferred class for methods on MESSAGE.
188 The message can inspect the PSET to decide on a particular message. A
189 `:method-class' property will usually override this decision: it's then
190 the programmer's responsibility to ensure that the selected method class
193 (export 'check-message-type)
194 (defgeneric check-message-type (message type)
196 "Check that TYPE is a suitable type for MESSAGE. Signal errors if not.
198 This is separated out of `shared-initialize', where it's called, so that
199 it can be overridden conveniently by subclasses."))
201 (export 'check-method-type)
202 (defgeneric check-method-type (method message type)
204 "Check that TYPE is a suitable type for METHOD. Signal errors if not.
206 This is separated out of `shared-initialize', where it's called, so that
207 it can be overridden conveniently by subclasses."))
209 ;;;----- That's all, folks --------------------------------------------------