1 ;;; written by David Lichteblau, based on code by Christophe Rhodes,
4 ;;; http://www.lichteblau.com/git/?p=specializable.git;a=blob_plain;f=specializable.lisp;hb=eb30d235951c3c1d128811278760f1db36cd336c
6 (defpackage "SPECIALIZABLE"
8 (:export "SPECIALIZABLE-GENERIC-FUNCTION" "SPECIALIZABLE-METHOD"
11 "SPECIALIZER-ACCEPTS-P" "SPECIALIZER-ACCEPTS-GENERALIZER-P"
14 "GENERALIZERS-OF-USING-CLASS"
15 "GENERALIZER-OF-USING-CLASS"
16 "COMPUTE-APPLICABLE-METHODS-USING-GENERALIZERS"
17 "GENERALIZER-EQUAL-HASH-KEY"
19 "DEFINE-EXTENDED-SPECIALIZER"))
21 (in-package "SPECIALIZABLE")
23 (defclass extended-specializer (sb-mop:specializer)
24 ;; FIXME: this doesn't actually do quite what I wanted.
25 ((direct-methods-table :allocation :class
26 :initform nil :accessor direct-methods-table)))
28 (defmethod sb-mop:add-direct-method ((specializer extended-specializer) method)
29 (let* ((table (direct-methods-table specializer))
30 (cell (assoc specializer table :test #'sb-pcl::same-specializer-p)))
32 (setf cell (cons specializer nil))
33 (push cell (direct-methods-table specializer)))
34 (push method (cdr cell))))
36 (defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method)
37 (let* ((table (direct-methods-table specializer))
38 (cell (assoc specializer table :test #'sb-pcl::same-specializer-p)))
39 (setf (cdr cell) (remove method (cdr cell)))))
41 (defmethod sb-mop:specializer-direct-methods ((specializer extended-specializer))
42 (cdr (assoc specializer (direct-methods-table specializer)
43 :test #'sb-pcl::same-specializer-p)))
44 (defmethod sb-mop:specializer-direct-generic-functions ((specializer extended-specializer))
45 (remove-duplicates (mapcar #'sb-mop:method-generic-function (sb-mop:specializer-direct-methods specializer))))
47 (defclass specializable-generic-function (standard-generic-function)
48 ((emf-table :initform (make-hash-table :test 'equal) :reader emf-table)
49 (cacheingp :initform t :initarg :cacheingp)
50 (single-arg-cacheing-p :initform t :initarg :single-arg-cacheing-p))
51 (:metaclass sb-mop:funcallable-standard-class)
52 (:default-initargs :method-class (find-class 'specializable-method)))
54 ;;; TODO: we don't use this class yet, but we might do later
55 (defclass specializable-method (standard-method) ())
58 (defun extended-specializer-name-p (name)
60 (get name 'extended-specializer-parser)))
62 (deftype extended-specializer-name ()
63 `(satisfies extended-specializer-name-p))
65 (defmacro define-extended-specializer (name (gf-var &rest args) &body body)
67 `(setf (get ',name 'extended-specializer-parser)
68 (lambda (,gf-var ,@args)
71 ;; doesn't work, because we'd have to dump GF into the fasl for the macro
73 ;;; (defun intern-extended-specializer (gf sname)
74 ;;; (destructuring-bind (kind &rest args) sname
75 ;;; (setf (gethash sname (generic-function-extended-specializers gf))
76 ;;; (apply (or (get kind 'extended-specializer-parser)
77 ;;; (error "not declared as an extended specializer name: ~A"
82 (defun make-extended-specializer (sname)
83 (destructuring-bind (kind &rest args) sname
84 (apply (or (get kind 'extended-specializer-parser)
85 (error "not declared as an extended specializer name: ~A"
87 '|This is not a generic function| ;fixme, see comment above
92 (defmethod sb-pcl:parse-specializer-using-class
93 ((gf specializable-generic-function) (specializer-name t))
94 (if (typep specializer-name '(cons extended-specializer-name))
95 (make-extended-specializer specializer-name)
98 (defmethod sb-pcl:make-method-specializers-form
99 ((gf specializable-generic-function) method snames env)
100 (declare (ignore method env))
103 ((typep name 'sb-mop:specializer) name)
104 ((symbolp name) `(find-class ',name))
107 (eql `(sb-mop:intern-eql-specializer ,(cadr name)))
108 (t `(make-extended-specializer ',name))))
109 (t (error "unexpected specializer name")))))
110 `(list ,@(mapcar #'parse snames))))
112 ;;; from Closette, changed to use some SBCL functions:
114 (defgeneric generalizer-equal-hash-key (generic-function generalizer))
115 (defmethod generalizer-equal-hash-key
116 ((gf specializable-generic-function) (g class))
117 (sb-pcl::class-wrapper g))
119 (defun first-arg-only-special-case (gf)
120 (let ((arg-info (sb-pcl::gf-arg-info gf)))
121 (and (slot-value gf 'single-arg-cacheing-p)
122 (>= (sb-pcl::arg-info-number-required arg-info) 1)
123 (every (lambda (x) (eql x t))
124 (cdr (sb-pcl::arg-info-metatypes arg-info))))))
126 ;;; FIXME: in some kind of order, the discriminating function needs to handle:
127 ;;; - argument count checking;
128 ;;; - DONE (in effective method) keyword argument validity;
129 ;;; - DONE flushing the emf cache on method addition/removal
130 ;;; - DONE (sort of, using wrappers/g-e-h-k) flushing the cache on class redefinition;
131 ;;; - cache thread-safety.
133 ;;; - DONE (in SBCL itself) interaction with TRACE et al.
134 (defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function))
136 ((not (slot-value gf 'cacheingp))
138 (let ((generalizers (generalizers-of-using-class gf args)))
139 (slow-method-lookup-and-call gf args generalizers))))
140 ((first-arg-only-special-case gf)
142 (let* ((generalizer (first (generalizers-of-using-class gf args))) ; TODO defeats purpose of special case
143 (key (generalizer-equal-hash-key gf generalizer))
144 (emfun (gethash key (emf-table gf) nil)))
146 (sb-pcl::invoke-emf emfun args)
147 (slow-method-lookup-and-call
148 gf args (list* generalizer
149 (mapcar (lambda (x) (generalizer-of-using-class gf x))
150 (rest (required-portion gf args)))))))))
153 (let* ((generalizers (generalizers-of-using-class gf args))
154 (keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers))
155 (emfun (gethash keys (emf-table gf) nil)))
157 (sb-pcl::invoke-emf emfun args)
158 (slow-method-lookup-and-call gf args generalizers)))))))
160 (defmethod reinitialize-instance :after ((gf specializable-generic-function) &key)
161 (clrhash (emf-table gf)))
163 (defun slow-method-lookup (gf args generalizers)
164 (multiple-value-bind (applicable-methods definitivep)
165 (compute-applicable-methods-using-generalizers gf generalizers)
167 (setf applicable-methods (compute-applicable-methods gf args)))
168 (values (compute-effective-method-function gf applicable-methods)
171 (defun slow-method-lookup-and-call (gf args generalizers)
172 (multiple-value-bind (emf cacheablep)
173 (slow-method-lookup gf args generalizers)
175 (let ((keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers)))
176 (if (first-arg-only-special-case gf)
177 (setf (gethash (car keys) (emf-table gf)) emf)
178 (setf (gethash keys (emf-table gf)) emf))))
179 (sb-pcl::invoke-emf emf args)))
181 (defun compute-effective-method-function (gf methods)
183 (lambda (&rest args) (apply #'no-applicable-method gf args))
184 (let* ((mc (sb-mop:generic-function-method-combination gf))
185 (sb-pcl::*applicable-methods* methods)
186 (em (sb-mop:compute-effective-method gf mc methods)))
187 (sb-pcl::make-effective-method-function gf em))))
189 ;; new, not in closette
190 ;;; FIXME: this is not actually sufficient argument checking
191 (defun required-portion (gf args)
192 (let ((number-required
193 (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf))))
194 (when (< (length args) number-required)
195 (error "Too few arguments to generic function ~S." gf))
196 (subseq args 0 number-required)))
198 (defgeneric generalizers-of-using-class (generic-function args))
200 (defmethod generalizers-of-using-class ((generic-function specializable-generic-function) args)
201 (mapcar (lambda (arg) (generalizer-of-using-class generic-function arg))
202 (required-portion generic-function args)))
204 (defgeneric generalizer-of-using-class (generic-function object))
205 (defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object)
208 (defgeneric specializer-accepts-generalizer-p (gf specializer generalizer))
209 (defmethod specializer-accepts-generalizer-p
210 ((gf specializable-generic-function) (specializer class) (generalizer class))
211 (if (subtypep generalizer specializer)
214 (defmethod specializer-accepts-generalizer-p
215 ((gf specializable-generic-function) (specializer sb-mop:eql-specializer) (generalizer class))
216 (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer)))
220 (defgeneric compute-applicable-methods-using-generalizers (gf generalizers))
221 (defmethod compute-applicable-methods-using-generalizers
222 ((gf specializable-generic-function) generalizers)
223 ;; differs from closette
224 (let ((result-definitive-p t))
225 (flet ((filter (method)
227 (multiple-value-bind (acceptsp definitivep)
228 (specializer-accepts-generalizer-p gf s g)
230 (setf result-definitive-p nil))
232 (sb-mop:method-specializers method) generalizers))
234 (method-more-specific-p gf m1 m2 generalizers)))
237 (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf)))
239 result-definitive-p))))
241 ;; new, not in closette
242 (defgeneric specializer-accepts-p (specializer object))
243 (defmethod specializer-accepts-p ((specializer class) object)
244 (typep object specializer))
245 (defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object)
246 (eq object (sb-mop:eql-specializer-object specializer)))
248 (defmethod compute-applicable-methods
249 ((gf specializable-generic-function) arguments)
250 ;; new, not in closette
253 (remove-if-not #'(lambda (method)
254 (every #'specializer-accepts-p
255 (sb-mop:method-specializers method)
257 (sb-mop:generic-function-methods gf)))
258 (let ((generalizers (generalizers-of-using-class gf arguments)))
260 (method-more-specific-p gf m1 m2 generalizers)))))
262 (defun method-more-specific-p (gf method1 method2 generalizers)
263 ;; FIXME: argument precedence order
265 (mapc #'(lambda (spec1 spec2 generalizer)
266 (ecase (specializer< gf spec1 spec2 generalizer)
269 ((nil > /=) (return nil))))
270 (sb-mop:method-specializers method1)
271 (sb-mop:method-specializers method2)
275 ;; new, not in closette
276 (defgeneric specializer< (gf s1 s2 generalizer))
277 (defmethod specializer<
278 ((gf specializable-generic-function) (s1 class) (s2 class) (generalizer class))
281 (let ((cpl (sb-mop:class-precedence-list generalizer)))
282 (if (find s2 (cdr (member s1 cpl)))
285 (defmethod specializer<
286 ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer)
287 (declare (ignore generalizer))
288 (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2))
291 (defmethod specializer< ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 class) generalizer)
292 (declare (ignore generalizer))
294 (defmethod specializer< ((gf specializable-generic-function) (c1 class) (c2 sb-mop:eql-specializer) generalizer)
295 (declare (ignore generalizer))