1 ;;; luna.el --- tiny OOP system kernel
3 ;; Copyright (C) 1999,2000 Free Software Foundation, Inc.
5 ;; Author: MORIOKA Tomohiko <tomo@m17n.org>
8 ;; This file is part of FLIM (Faithful Library about Internet Message).
10 ;; This program is free software; you can redistribute it and/or
11 ;; modify it under the terms of the GNU General Public License as
12 ;; published by the Free Software Foundation; either version 2, or (at
13 ;; your option) any later version.
15 ;; This program is distributed in the hope that it will be useful, but
16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 ;; General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 (eval-when-compile (require 'cl))
33 (defmacro luna-find-class (name)
34 "Return a luna-class that has NAME."
35 `(get ,name 'luna-class))
37 ;; Give NAME (symbol) the luna-class CLASS.
38 (defmacro luna-set-class (name class)
39 `(put ,name 'luna-class ,class))
41 ;; Return the obarray of luna-class CLASS.
42 (defmacro luna-class-obarray (class)
45 ;; Return the parents of luna-class CLASS.
46 (defmacro luna-class-parents (class)
49 ;; Return the number of slots of luna-class CLASS.
50 (defmacro luna-class-number-of-slots (class)
53 (defmacro luna-define-class (class &optional parents slots)
54 "Define CLASS as a luna-class.
55 CLASS always inherits the luna-class `standard-object'.
57 The optional 1st arg PARENTS is a list luna-class names. These
58 luna-classes are also inheritted by CLASS.
60 The optional 2nd arg SLOTS is a list of slots CLASS will have."
61 `(luna-define-class-function ',class ',(append parents '(standard-object))
65 ;; Define CLASS as a luna-class. PARENTS, if non-nil, is a list of
66 ;; luna-class names inherited by CLASS. SLOTS, if non-nil, is a list
67 ;; of slots belonging to CLASS.
69 (defun luna-define-class-function (class &optional parents slots)
70 (let ((oa (make-vector 31 0))
76 (setq parent (pop rest)
78 (mapatoms (lambda (sym)
79 (when (setq j (get sym 'luna-slot-index))
80 (setq name (symbol-name sym))
81 (unless (intern-soft name oa)
82 (put (intern name oa) 'luna-slot-index (+ j b))
84 (luna-class-obarray (luna-find-class parent))))
87 (setq name (symbol-name (pop rest)))
88 (unless (intern-soft name oa)
89 (put (intern name oa) 'luna-slot-index i)
91 (luna-set-class class (vector 'class oa parents i))))
94 ;; Return a member (slot or method) of CLASS that has name
97 (defun luna-class-find-member (class member-name)
98 (or (stringp member-name)
99 (setq member-name (symbol-name member-name)))
100 (or (intern-soft member-name (luna-class-obarray class))
101 (let ((parents (luna-class-parents class))
105 (setq ret (luna-class-find-member
106 (luna-find-class (pop parents))
111 ;; Return a member (slot or method) of CLASS that has name
112 ;; MEMBER-NAME. If CLASS doesnt' have such a member, make it in
115 (defsubst luna-class-find-or-make-member (class member-name)
116 (or (stringp member-name)
117 (setq member-name (symbol-name member-name)))
118 (intern member-name (luna-class-obarray class)))
121 ;; Return the index number of SLOT-NAME in CLASS.
123 (defmacro luna-class-slot-index (class slot-name)
124 `(get (luna-class-find-member ,class ,slot-name) 'luna-slot-index))
126 (defmacro luna-define-method (name &rest definition)
127 "Define NAME as a method of a luna class.
129 Usage of this macro follows:
131 (luna-define-method NAME [METHOD-QUALIFIER] ARGLIST [DOCSTRING] BODY...)
133 The optional 1st argument METHOD-QUALIFIER specifies when and how the
136 If it is :before, call the method before calling the parents' methods.
138 If it is :after, call the method after calling the parents' methods.
140 If it is :around, call the method only. The parents' methods can be
141 executed by calling the function `luna-call-next-method' in BODY.
143 Otherwize, call the method only, and the parents' methods are never
144 executed. In this case, METHOD-QUALIFIER is treated as ARGLIST.
146 ARGLIST has the form ((VAR CLASS) METHOD-ARG ...), where VAR is a
147 variable name that should be bound to an entity that receives the
148 message NAME, CLASS is a class name. The first argument to the method
149 is VAR, and the remaining arguments are METHOD-ARGs.
151 If VAR is nil, arguments to the method are METHOD-ARGs. This kind of
152 methods can't be called from generic-function (see
153 `luna-define-generic').
155 The optional 4th argument DOCSTRING is the documentation of the
156 method. If it is not string, it is treated as BODY.
158 The optional 5th BODY is the body of the method."
159 (let ((method-qualifier (pop definition))
160 args specializer class self)
161 (if (memq method-qualifier '(:before :after :around))
162 (setq args (pop definition))
163 (setq args method-qualifier
164 method-qualifier nil))
165 (setq specializer (car args)
166 class (nth 1 specializer)
167 self (car specializer))
168 `(let ((func (lambda ,(if self
169 (cons self (cdr args))
172 (sym (luna-class-find-or-make-member
173 (luna-find-class ',class) ',name))
174 (cache (get ',name 'luna-method-cache)))
176 (unintern ',class cache))
178 (put sym 'luna-method-qualifier ,method-qualifier))))
180 (put 'luna-define-method 'lisp-indent-function 'defun)
182 (def-edebug-spec luna-define-method
183 (&define name [&optional &or ":before" ":after" ":around"]
186 [&optional ["&optional" arg &rest arg]]
187 &optional ["&rest" arg])
191 ;; Return a list of method functions named SERVICE registered in the
194 (defun luna-class-find-parents-functions (class service)
195 (let ((parents (luna-class-parents class))
199 (setq ret (luna-class-find-functions
200 (luna-find-class (pop parents))
204 ;; Return a list of method functions named SERVICE registered in CLASS
207 (defun luna-class-find-functions (class service)
208 (let ((sym (luna-class-find-member class service)))
210 (cond ((eq (get sym 'luna-method-qualifier) :before)
211 (cons (symbol-function sym)
212 (luna-class-find-parents-functions class service)))
213 ((eq (get sym 'luna-method-qualifier) :after)
214 (nconc (luna-class-find-parents-functions class service)
215 (list (symbol-function sym))))
216 ((eq (get sym 'luna-method-qualifier) :around)
217 (cons sym (luna-class-find-parents-functions class service)))
219 (list (symbol-function sym))))
220 (luna-class-find-parents-functions class service))))
223 ;;; @ instance (entity)
226 (defmacro luna-class-name (entity)
227 "Return class-name of the ENTITY."
230 (defmacro luna-set-class-name (entity name)
231 `(aset ,entity 0 ,name))
233 (defmacro luna-get-obarray (entity)
236 (defmacro luna-set-obarray (entity obarray)
237 `(aset ,entity 1 ,obarray))
239 (defmacro luna-slot-index (entity slot-name)
240 `(luna-class-slot-index (luna-find-class (luna-class-name ,entity))
243 (defsubst luna-slot-value (entity slot)
244 "Return the value of SLOT of ENTITY."
245 (aref entity (luna-slot-index entity slot)))
247 (defsubst luna-set-slot-value (entity slot value)
248 "Store VALUE into SLOT of ENTITY."
249 (aset entity (luna-slot-index entity slot) value))
251 (defmacro luna-find-functions (entity service)
252 `(luna-class-find-functions (luna-find-class (luna-class-name ,entity))
255 (defsubst luna-send (entity message &rest luna-current-method-arguments)
256 "Send MESSAGE to ENTITY, and return the result.
257 ENTITY is an instance of a luna class, and MESSAGE is a method name of
259 LUNA-CURRENT-METHOD-ARGUMENTS is arguments of the MESSAGE."
260 (let ((luna-next-methods (luna-find-functions entity message))
262 luna-previous-return-value)
263 (while (and luna-next-methods
265 (setq luna-current-method (pop luna-next-methods)
266 luna-previous-return-value
267 (apply luna-current-method
268 luna-current-method-arguments))
269 (if (symbolp luna-current-method)
270 (not (eq (get luna-current-method
271 'luna-method-qualifier) :around))
273 luna-previous-return-value))
276 (defvar luna-next-methods nil)
277 (defvar luna-current-method-arguments nil))
279 (defun luna-call-next-method ()
280 "Call the next method in the current method function.
281 A method function that has :around qualifier should call this function
282 to execute the parents' methods."
283 (let (luna-current-method
284 luna-previous-return-value)
285 (while (and luna-next-methods
287 (setq luna-current-method (pop luna-next-methods)
288 luna-previous-return-value
289 (apply luna-current-method
290 luna-current-method-arguments))
291 (if (symbolp luna-current-method)
292 (not (eq (get luna-current-method
293 'luna-method-qualifier) :around))
295 luna-previous-return-value))
297 (defun luna-make-entity (class &rest init-args)
298 "Make an entity (instance) of luna-class CLASS and return it.
299 INIT-ARGS is a plist of the form (:SLOT1 VAL1 :SLOT2 VAL2 ...),
300 where SLOTs are slots of CLASS and the VALs are initial values of
301 the corresponding SLOTs."
302 (let* ((c (get class 'luna-class))
303 (v (make-vector (luna-class-number-of-slots c) nil)))
304 (luna-set-class-name v class)
305 (luna-set-obarray v (make-vector 7 0))
306 (apply #'luna-send v 'initialize-instance v init-args)))
309 ;;; @ interface (generic function)
312 ;; Find a method of ENTITY that handles MESSAGE, and call it with
313 ;; arguments LUNA-CURRENT-METHOD-ARGUMENTS.
315 (defun luna-apply-generic (entity message &rest luna-current-method-arguments)
316 (let* ((class (luna-class-name entity))
317 (cache (get message 'luna-method-cache))
318 (sym (intern-soft (symbol-name class) cache))
321 (setq luna-next-methods (symbol-value sym))
322 (setq luna-next-methods
323 (luna-find-functions entity message))
324 (set (intern (symbol-name class) cache)
326 (luna-call-next-method)))
329 ;; Convert ARGLIST (argument list spec for a method function) to the
330 ;; actual list of arguments.
332 (defsubst luna-arglist-to-arguments (arglist)
335 (let ((arg (car arglist)))
336 (or (memq arg '(&optional &rest))
337 (setq dest (cons arg dest))))
338 (setq arglist (cdr arglist)))
342 (defmacro luna-define-generic (name args &optional doc)
343 "Define a function NAME that provides a generic interface to the method NAME.
344 ARGS is the argument list for NAME. The first element of ARGS is an
347 The function handles a message sent to the entity by calling the
348 method with proper arguments.
350 The optional 3rd argument DOC is the documentation string for NAME."
353 (defun ,(intern (symbol-name name)) ,args
355 (luna-apply-generic ,(car args) ',name
356 ,@(luna-arglist-to-arguments args)))
357 (put ',name 'luna-method-cache (make-vector 31 0)))
359 (defun ,(intern (symbol-name name)) ,args
360 (luna-apply-generic ,(car args) ',name
361 ,@(luna-arglist-to-arguments args)))
362 (put ',name 'luna-method-cache (make-vector 31 0)))))
364 (put 'luna-define-generic 'lisp-indent-function 'defun)
370 (defun luna-define-internal-accessors (class-name)
371 "Define internal accessors for instances of the luna class CLASS-NAME.
373 Internal accessors are macros to refer and set a slot value of the
374 instances. For instance, if the class has SLOT, macros
375 CLASS-NAME-SLOT-internal and CLASS-NAME-set-SLOT-internal are defined.
377 CLASS-NAME-SLOT-internal accepts one argument INSTANCE, and returns
380 CLASS-NAME-set-SLOT-internal accepts two arguemnt INSTANCE and VALUE,
381 and sets SLOT to VALUE."
382 (let ((entity-class (luna-find-class class-name))
383 parents parent-class)
386 (if (luna-class-slot-index entity-class slot)
388 (setq parents (luna-class-parents entity-class))
390 (setq parent-class (luna-find-class (car parents)))
391 (if (luna-class-slot-index parent-class slot)
392 (throw 'derived nil))
393 (setq parents (cdr parents)))
396 (defmacro ,(intern (format "%s-%s-internal"
400 ,(luna-class-slot-index entity-class
401 (intern (symbol-name slot)))))
402 (defmacro ,(intern (format "%s-set-%s-internal"
406 ,(luna-class-slot-index
407 entity-class (intern (symbol-name slot)))
409 (luna-class-obarray entity-class))))
412 ;;; @ standard object
415 ;; Define super class of all luna classes.
416 (luna-define-class-function 'standard-object)
418 (luna-define-method initialize-instance ((entity standard-object)
420 "Initialize slots of ENTITY by INIT-ARGS."
421 (let* ((c (luna-find-class (luna-class-name entity)))
422 (oa (luna-class-obarray c))
425 (setq s (intern-soft (substring (symbol-name (pop init-args)) 1) oa)
428 (aset entity (get s 'luna-slot-index) i)))