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 ((direct-methods :initform nil
24 :accessor %specializer-direct-methods
25 :reader specializer-direct-methods)))
27 (defclass specializable-generic-function (standard-generic-function)
28 ((extended-specializers :initform (make-hash-table :test 'equal)
29 :reader generic-function-extended-specializers)
30 (emf-table :initform (make-hash-table :test 'equal) :reader emf-table))
31 (:metaclass sb-mop:funcallable-standard-class)
32 (:default-initargs :method-class (find-class 'specializable-method)))
34 (defclass specializable-method (standard-method)
35 ((lambda-expression :initarg :lambda-expression
36 :accessor specializable-method-lambda-expression)))
38 (defmacro define-extended-specializer (name (gf-var &rest args) &body body)
40 `(setf (get ',name 'extended-specializer-parser)
41 (lambda (,gf-var ,@args)
44 ;; doesn't work, because we'd have to dump GF into the fasl for the macro
46 ;;; (defun intern-extended-specializer (gf sname)
47 ;;; (destructuring-bind (kind &rest args) sname
48 ;;; (setf (gethash sname (generic-function-extended-specializers gf))
49 ;;; (apply (or (get kind 'extended-specializer-parser)
50 ;;; (error "not declared as an extended specializer name: ~A"
55 ;;; FIXME: this (and add/remove-direct-method) don't actually work
56 ;;; together, because two distinct calls to make-extended-specializer
57 ;;; return two distinct specializer objects. We need either to make
58 ;;; the extended specializers be interned, or to have them be
59 ;;; arbitrarily ephemeral but adjust specializer-direct-methods (and
60 ;;; implement specializer-direct-generic-functions) accordingly.
61 (defun make-extended-specializer (sname)
62 (destructuring-bind (kind &rest args) sname
63 (apply (or (get kind 'extended-specializer-parser)
64 (error "not declared as an extended specializer name: ~A"
66 '|This is not a generic function| ;fixme, see comment above
69 (defmethod sb-mop:add-direct-method ((specializer extended-specializer) method)
70 (pushnew method (%specializer-direct-methods specializer)))
72 (defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method)
73 (setf (%specializer-direct-methods specializer)
74 (remove method (specializer-direct-methods specializer))))
78 (defmethod sb-pcl:parse-specializer-using-class
79 ((gf specializable-generic-function) name)
81 ((typep name 'sb-mop:specializer) name)
82 ((symbolp name) (find-class name))
85 (eql (sb-mop:intern-eql-specializer (cadr name)))
86 (t (make-extended-specializer name))))
87 (t (error "unexpected specializer name"))))
89 (defmethod sb-pcl:make-method-specializers-form
90 ((gf specializable-generic-function) method snames env)
91 (declare (ignore method env))
94 ((typep name 'sb-mop:specializer) name)
95 ((symbolp name) `(find-class ',name))
98 (eql `(sb-mop:intern-eql-specializer ,(cadr name)))
99 (t `(make-extended-specializer ',name))))
100 (t (error "unexpected specializer name")))))
101 `(list ,@(mapcar #'parse snames))))
103 ;;; from Closette, changed to use some SBCL functions:
105 ;;; FIXME: this is not actually sufficient argument checking
106 (defun required-portion (gf args)
107 (let ((number-required
108 (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf))))
109 (when (< (length args) number-required)
110 (error "Too few arguments to generic function ~S." gf))
111 (subseq args 0 number-required)))
113 (defgeneric generalizer-equal-hash-key (generic-function generalizer))
114 (defmethod generalizer-equal-hash-key
115 ((gf specializable-generic-function) (g class))
116 (sb-pcl::class-wrapper g))
118 ;;; FIXME: in some kind of order, the discriminating function needs to handle:
119 ;;; - argument count checking;
120 ;;; - keyword argument validity;
121 ;;; - DONE flushing the emf cache on method addition/removal
122 ;;; - DONE (sort of, using wrappers/g-e-h-k) flushing the cache on class redefinition;
123 ;;; - cache thread-safety.
124 (defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function))
126 (let* ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
127 (required-portion gf args)))
128 (keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers))
129 (emfun (gethash keys (emf-table gf) nil)))
131 (sb-pcl::invoke-emf emfun args)
132 (slow-method-lookup gf args generalizers)))))
134 (defmethod reinitialize-instance :after ((gf specializable-generic-function) &key)
135 (clrhash (emf-table gf)))
137 (defun slow-method-lookup (gf args generalizers)
138 ;; differs from closette
139 (multiple-value-bind (applicable-methods definitivep)
140 (compute-applicable-methods-using-generalizers gf generalizers)
143 (compute-effective-method-function gf applicable-methods))
144 (keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers)))
145 (setf (gethash keys (emf-table gf)) emfun)
146 (sb-pcl::invoke-emf emfun args))
147 (sb-pcl::invoke-emf (compute-effective-method-function
148 gf (sb-mop:compute-applicable-methods gf args))
151 (defun compute-effective-method-function (gf methods)
152 (let* ((mc (sb-mop:generic-function-method-combination gf))
153 (em (sb-mop:compute-effective-method gf mc methods)))
154 (sb-pcl::make-effective-method-function gf em)))
156 ;; new, not in closette
157 (defgeneric generalizer-of-using-class (generic-function object))
158 (defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object)
161 (defgeneric specializer-accepts-generalizer-p (gf specializer generalizer))
162 (defmethod specializer-accepts-generalizer-p
163 ((gf specializable-generic-function) (specializer class) (generalizer class))
164 (if (subtypep generalizer specializer)
167 (defmethod specializer-accepts-generalizer-p
168 ((gf specializable-generic-function) (specializer sb-mop:eql-specializer) (generalizer class))
169 (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer)))
173 (defgeneric compute-applicable-methods-using-generalizers (gf generalizers))
174 (defmethod compute-applicable-methods-using-generalizers
175 ((gf specializable-generic-function) generalizers)
176 ;; differs from closette
177 (let ((result-definitive-p t))
178 (flet ((filter (method)
180 (multiple-value-bind (acceptsp definitivep)
181 (specializer-accepts-generalizer-p gf s g)
183 (setf result-definitive-p nil))
185 (sb-mop:method-specializers method) generalizers))
187 (method-more-specific-p gf m1 m2 generalizers)))
190 (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf)))
192 result-definitive-p))))
194 ;; new, not in closette
195 (defgeneric specializer-accepts-p (specializer object))
196 (defmethod specializer-accepts-p ((specializer class) object)
197 (typep object specializer))
198 (defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object)
199 (eq object (sb-mop:eql-specializer-object specializer)))
201 (defmethod compute-applicable-methods
202 ((gf specializable-generic-function) arguments)
203 ;; new, not in closette
206 (remove-if-not #'(lambda (method)
207 (every #'specializer-accepts-p
208 (sb-mop:method-specializers method)
210 (sb-mop:generic-function-methods gf)))
211 (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
212 (required-portion gf arguments))))
214 (method-more-specific-p gf m1 m2 generalizers)))))
216 (defun method-more-specific-p (gf method1 method2 generalizers)
217 ;; FIXME: argument precedence order
219 (mapc #'(lambda (spec1 spec2 generalizer)
220 (ecase (specializer< gf spec1 spec2 generalizer)
223 ((nil > /=) (return nil))))
224 (sb-mop:method-specializers method1)
225 (sb-mop:method-specializers method2)
229 ;; new, not in closette
230 (defgeneric specializer< (gf s1 s2 generalizer))
231 (defmethod specializer<
232 ((gf specializable-generic-function) (s1 class) (s2 class) (generalizer class))
235 (let ((cpl (sb-mop:class-precedence-list generalizer)))
236 (if (find s2 (cdr (member s1 cpl)))
239 (defmethod specializer<
240 ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer)
241 (declare (ignore generalizer))
242 (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2))
245 (defmethod specializer< ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 class) generalizer)
246 (declare (ignore generalizer))
248 (defmethod specializer< ((gf specializable-generic-function) (c1 class) (c2 sb-mop:eql-specializer) generalizer)
249 (declare (ignore generalizer))