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 "GENERALIZER-OF-USING-CLASS"
15 "COMPUTE-APPLICABLE-METHODS-USING-GENERALIZERS"
16 "GENERALIZER-EQUAL-HASH-KEY"
18 "DEFINE-EXTENDED-SPECIALIZER"))
20 (in-package "SPECIALIZABLE")
22 (defclass extended-specializer (sb-mop:specializer)
23 ;; FIXME: this doesn't actually do quite what I wanted.
24 ((direct-methods-table :allocation :class
25 :initform nil :accessor direct-methods-table)))
27 (defmethod sb-mop:add-direct-method ((specializer extended-specializer) method)
28 (let* ((table (direct-methods-table specializer))
29 (cell (assoc specializer table :test #'sb-pcl::same-specializer-p)))
31 (setf cell (cons specializer nil))
32 (push cell (direct-methods-table specializer)))
33 (push method (cdr cell))))
35 (defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method)
36 (let* ((table (direct-methods-table specializer))
37 (cell (assoc specializer table :test #'sb-pcl::same-specializer-p)))
38 (setf (cdr cell) (remove method (cdr cell)))))
40 (defmethod sb-mop:specializer-direct-methods ((specializer extended-specializer))
41 (cdr (assoc specializer (direct-methods-table specializer)
42 :test #'sb-pcl::same-specializer-p)))
43 (defmethod sb-mop:specializer-direct-generic-functions ((specializer extended-specializer))
44 (remove-duplicates (mapcar #'sb-mop:method-generic-function (sb-mop:specializer-direct-methods specializer))))
46 (defclass specializable-generic-function (standard-generic-function)
47 ((emf-table :initform (make-hash-table :test 'equal) :reader emf-table)
48 (cacheingp :initform t :initarg :cacheingp)
49 (single-arg-cacheing-p :initform t :initarg :single-arg-cacheing-p))
50 (:metaclass sb-mop:funcallable-standard-class)
51 (:default-initargs :method-class (find-class 'specializable-method)))
53 ;;; TODO: we don't use this class yet, but we might do later
54 (defclass specializable-method (standard-method) ())
57 (defun extended-specializer-name-p (name)
59 (get name 'extended-specializer-parser)))
61 (deftype extended-specializer-name ()
62 `(satisfies extended-specializer-name-p))
64 (defmacro define-extended-specializer (name (gf-var &rest args) &body body)
66 `(setf (get ',name 'extended-specializer-parser)
67 (lambda (,gf-var ,@args)
70 ;; doesn't work, because we'd have to dump GF into the fasl for the macro
72 ;;; (defun intern-extended-specializer (gf sname)
73 ;;; (destructuring-bind (kind &rest args) sname
74 ;;; (setf (gethash sname (generic-function-extended-specializers gf))
75 ;;; (apply (or (get kind 'extended-specializer-parser)
76 ;;; (error "not declared as an extended specializer name: ~A"
81 (defun make-extended-specializer (sname)
82 (destructuring-bind (kind &rest args) sname
83 (apply (or (get kind 'extended-specializer-parser)
84 (error "not declared as an extended specializer name: ~A"
86 '|This is not a generic function| ;fixme, see comment above
91 (defmethod sb-pcl:parse-specializer-using-class
92 ((gf specializable-generic-function) (specializer-name t))
93 (if (typep specializer-name '(cons extended-specializer-name))
94 (make-extended-specializer specializer-name)
97 (defmethod sb-pcl:make-method-specializers-form
98 ((gf specializable-generic-function) method snames env)
99 (declare (ignore method env))
102 ((typep name 'sb-mop:specializer) name)
103 ((symbolp name) `(find-class ',name))
106 (eql `(sb-mop:intern-eql-specializer ,(cadr name)))
107 (t `(make-extended-specializer ',name))))
108 (t (error "unexpected specializer name")))))
109 `(list ,@(mapcar #'parse snames))))
111 ;;; from Closette, changed to use some SBCL functions:
113 ;;; FIXME: this is not actually sufficient argument checking
114 (defun required-portion (gf args)
115 (let ((number-required
116 (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf))))
117 (when (< (length args) number-required)
118 (error "Too few arguments to generic function ~S." gf))
119 (subseq args 0 number-required)))
121 (defgeneric generalizer-equal-hash-key (generic-function generalizer))
122 (defmethod generalizer-equal-hash-key
123 ((gf specializable-generic-function) (g class))
124 (sb-pcl::class-wrapper g))
126 (defun first-arg-only-special-case (gf)
127 (let ((arg-info (sb-pcl::gf-arg-info gf)))
128 (and (slot-value gf 'single-arg-cacheing-p)
129 (>= (sb-pcl::arg-info-number-required arg-info) 1)
130 (every (lambda (x) (eql x t))
131 (cdr (sb-pcl::arg-info-metatypes arg-info))))))
133 ;;; FIXME: in some kind of order, the discriminating function needs to handle:
134 ;;; - argument count checking;
135 ;;; - DONE (in effective method) keyword argument validity;
136 ;;; - DONE flushing the emf cache on method addition/removal
137 ;;; - DONE (sort of, using wrappers/g-e-h-k) flushing the cache on class redefinition;
138 ;;; - cache thread-safety.
140 ;;; - DONE (in SBCL itself) interaction with TRACE et al.
141 (defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function))
143 ((not (slot-value gf 'cacheingp))
145 (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
147 (slow-method-lookup-and-call gf args generalizers))))
148 ((first-arg-only-special-case gf)
150 (let* ((g (generalizer-of-using-class gf (car args)))
151 (k (generalizer-equal-hash-key gf g))
152 (emfun (gethash k (emf-table gf) nil)))
154 (sb-pcl::invoke-emf emfun args)
155 (slow-method-lookup-and-call
156 gf args (cons g (mapcar (lambda (x) (generalizer-of-using-class gf x))
157 (cdr (required-portion gf args)))))))))
160 (let* ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
161 (required-portion gf args)))
162 (keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers))
163 (emfun (gethash keys (emf-table gf) nil)))
165 (sb-pcl::invoke-emf emfun args)
166 (slow-method-lookup-and-call gf args generalizers)))))))
168 (defmethod reinitialize-instance :after ((gf specializable-generic-function) &key)
169 (clrhash (emf-table gf)))
171 (defun slow-method-lookup (gf args generalizers)
172 (multiple-value-bind (applicable-methods definitivep)
173 (compute-applicable-methods-using-generalizers gf generalizers)
175 (setf applicable-methods (compute-applicable-methods gf args)))
176 (values (compute-effective-method-function gf applicable-methods)
179 (defun slow-method-lookup-and-call (gf args generalizers)
180 (multiple-value-bind (emf cacheablep)
181 (slow-method-lookup gf args generalizers)
183 (let ((keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers)))
184 (if (first-arg-only-special-case gf)
185 (setf (gethash (car keys) (emf-table gf)) emf)
186 (setf (gethash keys (emf-table gf)) emf))))
187 (sb-pcl::invoke-emf emf args)))
189 (defun compute-effective-method-function (gf methods)
191 (lambda (&rest args) (apply #'no-applicable-method gf args))
192 (let* ((mc (sb-mop:generic-function-method-combination gf))
193 (sb-pcl::*applicable-methods* methods)
194 (em (sb-mop:compute-effective-method gf mc methods)))
195 (sb-pcl::make-effective-method-function gf em))))
197 ;; new, not in closette
198 (defgeneric generalizer-of-using-class (generic-function object))
199 (defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object)
202 (defgeneric specializer-accepts-generalizer-p (gf specializer generalizer))
203 (defmethod specializer-accepts-generalizer-p
204 ((gf specializable-generic-function) (specializer class) (generalizer class))
205 (if (subtypep generalizer specializer)
208 (defmethod specializer-accepts-generalizer-p
209 ((gf specializable-generic-function) (specializer sb-mop:eql-specializer) (generalizer class))
210 (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer)))
214 (defgeneric compute-applicable-methods-using-generalizers (gf generalizers))
215 (defmethod compute-applicable-methods-using-generalizers
216 ((gf specializable-generic-function) generalizers)
217 ;; differs from closette
218 (let ((result-definitive-p t))
219 (flet ((filter (method)
221 (multiple-value-bind (acceptsp definitivep)
222 (specializer-accepts-generalizer-p gf s g)
224 (setf result-definitive-p nil))
226 (sb-mop:method-specializers method) generalizers))
228 (method-more-specific-p gf m1 m2 generalizers)))
231 (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf)))
233 result-definitive-p))))
235 ;; new, not in closette
236 (defgeneric specializer-accepts-p (specializer object))
237 (defmethod specializer-accepts-p ((specializer class) object)
238 (typep object specializer))
239 (defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object)
240 (eq object (sb-mop:eql-specializer-object specializer)))
242 (defmethod compute-applicable-methods
243 ((gf specializable-generic-function) arguments)
244 ;; new, not in closette
247 (remove-if-not #'(lambda (method)
248 (every #'specializer-accepts-p
249 (sb-mop:method-specializers method)
251 (sb-mop:generic-function-methods gf)))
252 (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
253 (required-portion gf arguments))))
255 (method-more-specific-p gf m1 m2 generalizers)))))
257 (defun method-more-specific-p (gf method1 method2 generalizers)
258 ;; FIXME: argument precedence order
260 (mapc #'(lambda (spec1 spec2 generalizer)
261 (ecase (specializer< gf spec1 spec2 generalizer)
264 ((nil > /=) (return nil))))
265 (sb-mop:method-specializers method1)
266 (sb-mop:method-specializers method2)
270 ;; new, not in closette
271 (defgeneric specializer< (gf s1 s2 generalizer))
272 (defmethod specializer<
273 ((gf specializable-generic-function) (s1 class) (s2 class) (generalizer class))
276 (let ((cpl (sb-mop:class-precedence-list generalizer)))
277 (if (find s2 (cdr (member s1 cpl)))
280 (defmethod specializer<
281 ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer)
282 (declare (ignore generalizer))
283 (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2))
286 (defmethod specializer< ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 class) generalizer)
287 (declare (ignore generalizer))
289 (defmethod specializer< ((gf specializable-generic-function) (c1 class) (c2 sb-mop:eql-specializer) generalizer)
290 (declare (ignore generalizer))