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"
17 "DEFINE-EXTENDED-SPECIALIZER"))
19 (in-package "SPECIALIZABLE")
21 (defclass extended-specializer (sb-mop:specializer)
22 ((direct-methods :initform nil
23 :accessor %specializer-direct-methods
24 :reader specializer-direct-methods)))
26 (defclass specializable-generic-function (standard-generic-function)
27 ((extended-specializers :initform (make-hash-table :test 'equal)
28 :reader generic-function-extended-specializers)
29 (emf-table :initform (make-hash-table :test 'equal) :reader emf-table))
30 (:metaclass sb-mop:funcallable-standard-class)
31 (:default-initargs :method-class (find-class 'specializable-method)))
33 (defclass specializable-method (standard-method)
34 ((lambda-expression :initarg :lambda-expression
35 :accessor specializable-method-lambda-expression)))
37 (defmacro define-extended-specializer (name (gf-var &rest args) &body body)
39 `(setf (get ',name 'extended-specializer-parser)
40 (lambda (,gf-var ,@args)
43 ;; doesn't work, because we'd have to dump GF into the fasl for the macro
45 ;;; (defun intern-extended-specializer (gf sname)
46 ;;; (destructuring-bind (kind &rest args) sname
47 ;;; (setf (gethash sname (generic-function-extended-specializers gf))
48 ;;; (apply (or (get kind 'extended-specializer-parser)
49 ;;; (error "not declared as an extended specializer name: ~A"
54 ;;; FIXME: this (and add/remove-direct-method) don't actually work
55 ;;; together, because two distinct calls to make-extended-specializer
56 ;;; return two distinct specializer objects. We need either to make
57 ;;; the extended specializers be interned, or to have them be
58 ;;; arbitrarily ephemeral but adjust specializer-direct-methods (and
59 ;;; implement specializer-direct-generic-functions) accordingly.
60 (defun make-extended-specializer (sname)
61 (destructuring-bind (kind &rest args) sname
62 (apply (or (get kind 'extended-specializer-parser)
63 (error "not declared as an extended specializer name: ~A"
65 '|This is not a generic function| ;fixme, see comment above
68 (defmethod sb-mop:add-direct-method ((specializer extended-specializer) method)
69 (pushnew method (%specializer-direct-methods specializer)))
71 (defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method)
72 (setf (%specializer-direct-methods specializer)
73 (remove method (specializer-direct-methods specializer))))
77 (defmethod sb-pcl:parse-specializer-using-class
78 ((gf specializable-generic-function) name)
80 ((typep name 'sb-mop:specializer) name)
81 ((symbolp name) (find-class name))
84 (eql (sb-mop:intern-eql-specializer (cadr name)))
85 (t (make-extended-specializer name))))
86 (t (error "unexpected specializer name"))))
88 (defmethod sb-pcl:make-method-specializers-form
89 ((gf specializable-generic-function) method snames env)
90 (declare (ignore method env))
93 ((typep name 'sb-mop:specializer) name)
94 ((symbolp name) `(find-class ',name))
97 (eql `(sb-mop:intern-eql-specializer ,(cadr name)))
98 (t `(make-extended-specializer ',name))))
99 (t (error "unexpected specializer name")))))
100 `(list ,@(mapcar #'parse snames))))
102 ;;; from Closette, changed to use some SBCL functions:
104 ;;; FIXME: this is not actually sufficient argument checking
105 (defun required-portion (gf args)
106 (let ((number-required
107 (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf))))
108 (when (< (length args) number-required)
109 (error "Too few arguments to generic function ~S." gf))
110 (subseq args 0 number-required)))
112 ;;; FIXME: in some kind of order, the discriminating function needs to handle:
113 ;;; - argument count checking;
114 ;;; - keyword argument validity;
115 ;;; - DONE flushing the emf cache on method addition/removal
116 ;;; - flushing the cache on class redefinition;
117 ;;; - cache thread-safety.
118 (defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function))
120 (let* ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
121 (required-portion gf args)))
122 (emfun (gethash generalizers (emf-table gf) nil)))
124 (sb-pcl::invoke-emf emfun args)
125 (slow-method-lookup gf args generalizers)))))
127 (defmethod reinitialize-instance :after ((gf specializable-generic-function) &key)
128 (clrhash (emf-table gf)))
130 (defun slow-method-lookup (gf args generalizers)
131 ;; differs from closette
132 (multiple-value-bind (applicable-methods definitivep)
133 (compute-applicable-methods-using-generalizers gf generalizers)
136 (compute-effective-method-function gf applicable-methods)))
137 (setf (gethash generalizers (emf-table gf)) emfun)
138 (sb-pcl::invoke-emf emfun args))
139 (sb-pcl::invoke-emf (compute-effective-method-function
140 gf (sb-mop:compute-applicable-methods gf args))
143 (defun compute-effective-method-function (gf methods)
144 (let* ((mc (sb-mop:generic-function-method-combination gf))
145 (em (sb-mop:compute-effective-method gf mc methods)))
146 (sb-pcl::make-effective-method-function gf em)))
148 ;; new, not in closette
149 (defgeneric generalizer-of-using-class (generic-function object))
150 (defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object)
153 (defgeneric specializer-accepts-generalizer-p (gf specializer generalizer))
154 (defmethod specializer-accepts-generalizer-p
155 ((gf specializable-generic-function) (specializer class) (generalizer class))
156 (if (subtypep generalizer specializer)
159 (defmethod specializer-accepts-generalizer-p
160 ((gf specializable-generic-function) (specializer sb-mop:eql-specializer) (generalizer class))
161 (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer)))
165 (defgeneric compute-applicable-methods-using-generalizers (gf generalizers))
166 (defmethod compute-applicable-methods-using-generalizers
167 ((gf specializable-generic-function) generalizers)
168 ;; differs from closette
169 (let ((result-definitive-p t))
170 (flet ((filter (method)
172 (multiple-value-bind (acceptsp definitivep)
173 (specializer-accepts-generalizer-p gf s g)
175 (setf result-definitive-p nil))
177 (sb-mop:method-specializers method) generalizers))
179 (method-more-specific-p gf m1 m2 generalizers)))
182 (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf)))
184 result-definitive-p))))
186 ;; new, not in closette
187 (defgeneric specializer-accepts-p (specializer object))
188 (defmethod specializer-accepts-p ((specializer class) object)
189 (typep object specializer))
190 (defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object)
191 (eq object (sb-mop:eql-specializer-object specializer)))
193 (defmethod compute-applicable-methods
194 ((gf specializable-generic-function) arguments)
195 ;; new, not in closette
198 (remove-if-not #'(lambda (method)
199 (every #'specializer-accepts-p
200 (sb-mop:method-specializers method)
202 (sb-mop:generic-function-methods gf)))
203 (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
204 (required-portion gf arguments))))
206 (method-more-specific-p gf m1 m2 generalizers)))))
208 (defun method-more-specific-p (gf method1 method2 generalizers)
209 ;; FIXME: argument precedence order
211 (mapc #'(lambda (spec1 spec2 generalizer)
212 (ecase (specializer< gf spec1 spec2 generalizer)
215 ((nil > /=) (return nil))))
216 (sb-mop:method-specializers method1)
217 (sb-mop:method-specializers method2)
221 ;; new, not in closette
222 (defgeneric specializer< (gf s1 s2 generalizer))
223 (defmethod specializer<
224 ((gf specializable-generic-function) (s1 class) (s2 class) (generalizer class))
227 (let ((cpl (sb-mop:class-precedence-list generalizer)))
228 (if (find s2 (cdr (member s1 cpl)))
231 (defmethod specializer<
232 ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer)
233 (declare (ignore generalizer))
234 (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2))
237 (defmethod specializer< ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 class) generalizer)
238 (declare (ignore generalizer))
240 (defmethod specializer< ((gf specializable-generic-function) (c1 class) (c2 sb-mop:eql-specializer) generalizer)
241 (declare (ignore generalizer))