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-CLASS-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 (defun make-extended-specializer (sname)
55 (destructuring-bind (kind &rest args) sname
56 (apply (or (get kind 'extended-specializer-parser)
57 (error "not declared as an extended specializer name: ~A"
59 '|This is not a generic function| ;fixme, see comment above
62 (defmethod sb-mop:add-direct-method ((specializer extended-specializer) method)
63 (pushnew method (%specializer-direct-methods specializer)))
65 (defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method)
66 (setf (%specializer-direct-methods specializer)
67 (remove method (specializer-direct-methods specializer))))
71 (defmethod sb-pcl:parse-specializer-using-class
72 ((gf specializable-generic-function) name)
74 ((typep name 'sb-mop:specializer) name)
75 ((symbolp name) (find-class name))
78 (eql (sb-mop:intern-eql-specializer (cadr name)))
79 (t (make-extended-specializer name))))
80 (t (error "unexpected specializer name"))))
82 (defmethod sb-pcl:make-method-specializers-form
83 ((gf specializable-generic-function) method snames env)
84 (declare (ignore method env))
87 ((typep name 'sb-mop:specializer) name)
88 ((symbolp name) `(find-class ',name))
91 (eql `(sb-mop:intern-eql-specializer ,(cadr name)))
92 (t `(make-extended-specializer ',name))))
93 (t (error "unexpected specializer name")))))
94 `(list ,@(mapcar #'parse snames))))
96 ;;; from Closette, changed to use some SBCL functions:
98 ;;; FIXME: this is not actually sufficient argument checking
99 (defun required-portion (gf args)
100 (let ((number-required
101 (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf))))
102 (when (< (length args) number-required)
103 (error "Too few arguments to generic function ~S." gf))
104 (subseq args 0 number-required)))
106 ;;; FIXME: in some kind of order, the discriminating function needs to handle:
107 ;;; - argument count checking;
108 ;;; - keyword argument validity;
109 ;;; - flushing the emf cache on method addition/removal
110 ;;; - flushing the cache on class redefinition;
111 ;;; - cache thread-safety.
112 (defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function))
114 (let* ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
115 (required-portion gf args)))
116 (emfun (gethash generalizers (emf-table gf) nil)))
118 (sb-pcl::invoke-emf emfun args)
119 (slow-method-lookup gf args generalizers)))))
121 (defun slow-method-lookup (gf args generalizers)
122 ;; differs from closette
123 (multiple-value-bind (applicable-methods definitivep)
124 (compute-applicable-methods-using-generalizers gf generalizers)
127 (compute-effective-method-function gf applicable-methods)))
128 (setf (gethash generalizers (emf-table gf)) emfun)
129 (sb-pcl::invoke-emf emfun args))
130 (sb-pcl::invoke-emf (compute-effective-method-function
131 gf (sb-mop:compute-applicable-methods gf args))
134 (defun compute-effective-method-function (gf methods)
135 (let* ((mc (sb-mop:generic-function-method-combination gf))
136 (em (sb-mop:compute-effective-method gf mc methods)))
137 (sb-pcl::make-effective-method-function gf em)))
139 ;; new, not in closette
140 (defgeneric generalizer-of-using-class (generic-function object))
141 (defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object)
144 (defgeneric specializer-accepts-generalizer-p (specializer generalizer))
145 (defmethod specializer-accepts-generalizer-p ((specializer class) (generalizer class))
146 ;; does the specializer's object have the -same- class as the the actual
148 (if (subtypep generalizer specializer)
149 ;; definitive: this method matches all instances of this class
151 ;; definitive: this method doesn't match instances of this class
153 (defmethod specializer-accepts-generalizer-p
154 ((specializer sb-mop:eql-specializer) (generalizer class))
155 ;; does the specializer's object have the -same- class as the actual
157 (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer)))
158 ;; not definitive, since the actual object might differ
160 ;; definitely not the same object
163 (defgeneric compute-applicable-methods-using-generalizers (gf generalizers))
164 (defmethod compute-applicable-methods-using-generalizers
165 ((gf specializable-generic-function) generalizers)
166 ;; differs from closette
167 (let ((result-definitive-p t))
168 (flet ((filter (method)
170 (multiple-value-bind (acceptsp definitivep)
171 (specializer-accepts-generalizer-p s g)
173 (setf result-definitive-p nil))
175 (sb-mop:method-specializers method) generalizers))
177 (method-more-specific-p gf m1 m2 generalizers)))
180 (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf)))
182 result-definitive-p))))
184 ;; new, not in closette
185 (defgeneric specializer-accepts-p (specializer object))
186 (defmethod specializer-accepts-p ((specializer class) object)
187 (typep object specializer))
188 (defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object)
189 (eq object (sb-mop:eql-specializer-object specializer)))
191 (defmethod compute-applicable-methods
192 ((gf specializable-generic-function) arguments)
193 ;; new, not in closette
196 (remove-if-not #'(lambda (method)
197 (every #'specializer-accepts-p
198 (sb-mop:method-specializers method)
200 (sb-mop:generic-function-methods gf)))
201 (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x))
202 (required-portion gf arguments))))
204 (method-more-specific-p gf m1 m2 generalizers)))))
206 (defun method-more-specific-p (gf method1 method2 generalizers)
207 ;; differs from closette
208 (declare (ignore gf))
209 ;; FIXME: argument precedence order
211 (mapc #'(lambda (spec1 spec2 generalizer)
212 (ecase (specializer< 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< (s1 s2 generalizer))
223 (defmethod specializer< ((s1 class) (s2 class) (generalizer class))
226 (let ((cpl (sb-mop:class-precedence-list generalizer)))
227 (if (find s2 (cdr (member s1 cpl)))
230 (defmethod specializer<
231 ((s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer)
232 (declare (ignore generalizer))
233 (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2))
236 (defmethod specializer< ((s1 sb-mop:eql-specializer) (s2 class) generalizer)
237 (declare (ignore generalizer))
239 (defmethod specializer< ((c1 class) (c2 sb-mop:eql-specializer) generalizer)
240 (declare (ignore generalizer))