X-Git-Url: http://christophe.rhodes.io/gitweb/?p=specializable.git;a=blobdiff_plain;f=src%2Fspecializable.lisp;fp=src%2Fspecializable.lisp;h=8d01319b1267e28a5da465263fbb8b4df27163c5;hp=0000000000000000000000000000000000000000;hb=9dd8f1378407cae8ec7b6b05a8b3c152bc4a5f9b;hpb=d55ebbbcbd77023c799d8d95dce5d3772aec5841 diff --git a/src/specializable.lisp b/src/specializable.lisp new file mode 100644 index 0000000..8d01319 --- /dev/null +++ b/src/specializable.lisp @@ -0,0 +1,291 @@ +;;; written by David Lichteblau, based on code by Christophe Rhodes, +;;; Closette, and SBCL +;;; +;;; http://www.lichteblau.com/git/?p=specializable.git;a=blob_plain;f=specializable.lisp;hb=eb30d235951c3c1d128811278760f1db36cd336c + +(defpackage "SPECIALIZABLE" + (:use "CL" "SB-EXT") + (:export "SPECIALIZABLE-GENERIC-FUNCTION" "SPECIALIZABLE-METHOD" + "EXTENDED-SPECIALIZER" + + "SPECIALIZER-ACCEPTS-P" "SPECIALIZER-ACCEPTS-GENERALIZER-P" + "SPECIALIZER<" + + "GENERALIZER-OF-USING-CLASS" + "COMPUTE-APPLICABLE-METHODS-USING-GENERALIZERS" + "GENERALIZER-EQUAL-HASH-KEY" + + "DEFINE-EXTENDED-SPECIALIZER")) + +(in-package "SPECIALIZABLE") + +(defclass extended-specializer (sb-mop:specializer) + ;; FIXME: this doesn't actually do quite what I wanted. + ((direct-methods-table :allocation :class + :initform nil :accessor direct-methods-table))) + +(defmethod sb-mop:add-direct-method ((specializer extended-specializer) method) + (let* ((table (direct-methods-table specializer)) + (cell (assoc specializer table :test #'sb-pcl::same-specializer-p))) + (unless cell + (setf cell (cons specializer nil)) + (push cell (direct-methods-table specializer))) + (push method (cdr cell)))) + +(defmethod sb-mop:remove-direct-method ((specializer extended-specializer) method) + (let* ((table (direct-methods-table specializer)) + (cell (assoc specializer table :test #'sb-pcl::same-specializer-p))) + (setf (cdr cell) (remove method (cdr cell))))) + +(defmethod sb-mop:specializer-direct-methods ((specializer extended-specializer)) + (cdr (assoc specializer (direct-methods-table specializer) + :test #'sb-pcl::same-specializer-p))) +(defmethod sb-mop:specializer-direct-generic-functions ((specializer extended-specializer)) + (remove-duplicates (mapcar #'sb-mop:method-generic-function (sb-mop:specializer-direct-methods specializer)))) + +(defclass specializable-generic-function (standard-generic-function) + ((emf-table :initform (make-hash-table :test 'equal) :reader emf-table) + (cacheingp :initform t :initarg :cacheingp) + (single-arg-cacheing-p :initform t :initarg :single-arg-cacheing-p)) + (:metaclass sb-mop:funcallable-standard-class) + (:default-initargs :method-class (find-class 'specializable-method))) + +;;; TODO: we don't use this class yet, but we might do later +(defclass specializable-method (standard-method) ()) + +;;; TODO use info? +(defun extended-specializer-name-p (name) + (and (symbolp name) + (get name 'extended-specializer-parser))) + +(deftype extended-specializer-name () + `(satisfies extended-specializer-name-p)) + +(defmacro define-extended-specializer (name (gf-var &rest args) &body body) + ;; FIXME: unparser + `(setf (get ',name 'extended-specializer-parser) + (lambda (,gf-var ,@args) + ,@body))) + +;; doesn't work, because we'd have to dump GF into the fasl for the macro +;; expansion +;;; (defun intern-extended-specializer (gf sname) +;;; (destructuring-bind (kind &rest args) sname +;;; (setf (gethash sname (generic-function-extended-specializers gf)) +;;; (apply (or (get kind 'extended-specializer-parser) +;;; (error "not declared as an extended specializer name: ~A" +;;; kind)) +;;; gf +;;; args)))) + +(defun make-extended-specializer (sname) + (destructuring-bind (kind &rest args) sname + (apply (or (get kind 'extended-specializer-parser) + (error "not declared as an extended specializer name: ~A" + kind)) + '|This is not a generic function| ;fixme, see comment above + args))) + +;;; from SBCL: + +(defmethod sb-pcl:parse-specializer-using-class + ((gf specializable-generic-function) (specializer-name t)) + (if (typep specializer-name '(cons extended-specializer-name)) + (make-extended-specializer specializer-name) + (call-next-method))) + +(defmethod sb-pcl:make-method-specializers-form + ((gf specializable-generic-function) method snames env) + (declare (ignore method env)) + (flet ((parse (name) + (cond + ((typep name 'sb-mop:specializer) name) + ((symbolp name) `(find-class ',name)) + ((consp name) + (case (car name) + (eql `(sb-mop:intern-eql-specializer ,(cadr name))) + (t `(make-extended-specializer ',name)))) + (t (error "unexpected specializer name"))))) + `(list ,@(mapcar #'parse snames)))) + +;;; from Closette, changed to use some SBCL functions: + +;;; FIXME: this is not actually sufficient argument checking +(defun required-portion (gf args) + (let ((number-required + (sb-pcl::arg-info-number-required (sb-pcl::gf-arg-info gf)))) + (when (< (length args) number-required) + (error "Too few arguments to generic function ~S." gf)) + (subseq args 0 number-required))) + +(defgeneric generalizer-equal-hash-key (generic-function generalizer)) +(defmethod generalizer-equal-hash-key + ((gf specializable-generic-function) (g class)) + (sb-pcl::class-wrapper g)) + +(defun first-arg-only-special-case (gf) + (let ((arg-info (sb-pcl::gf-arg-info gf))) + (and (slot-value gf 'single-arg-cacheing-p) + (>= (sb-pcl::arg-info-number-required arg-info) 1) + (every (lambda (x) (eql x t)) + (cdr (sb-pcl::arg-info-metatypes arg-info)))))) + +;;; FIXME: in some kind of order, the discriminating function needs to handle: +;;; - argument count checking; +;;; - DONE (in effective method) keyword argument validity; +;;; - DONE flushing the emf cache on method addition/removal +;;; - DONE (sort of, using wrappers/g-e-h-k) flushing the cache on class redefinition; +;;; - cache thread-safety. +;;; - speed +;;; - DONE (in SBCL itself) interaction with TRACE et al. +(defmethod sb-mop:compute-discriminating-function ((gf specializable-generic-function)) + (cond + ((not (slot-value gf 'cacheingp)) + (lambda (&rest args) + (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x)) + args))) + (slow-method-lookup-and-call gf args generalizers)))) + ((first-arg-only-special-case gf) + (lambda (&rest args) + (let* ((g (generalizer-of-using-class gf (car args))) + (k (generalizer-equal-hash-key gf g)) + (emfun (gethash k (emf-table gf) nil))) + (if emfun + (sb-pcl::invoke-emf emfun args) + (slow-method-lookup-and-call + gf args (cons g (mapcar (lambda (x) (generalizer-of-using-class gf x)) + (cdr (required-portion gf args))))))))) + (t + (lambda (&rest args) + (let* ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x)) + (required-portion gf args))) + (keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers)) + (emfun (gethash keys (emf-table gf) nil))) + (if emfun + (sb-pcl::invoke-emf emfun args) + (slow-method-lookup-and-call gf args generalizers))))))) + +(defmethod reinitialize-instance :after ((gf specializable-generic-function) &key) + (clrhash (emf-table gf))) + +(defun slow-method-lookup (gf args generalizers) + (multiple-value-bind (applicable-methods definitivep) + (compute-applicable-methods-using-generalizers gf generalizers) + (unless definitivep + (setf applicable-methods (compute-applicable-methods gf args))) + (values (compute-effective-method-function gf applicable-methods) + definitivep))) + +(defun slow-method-lookup-and-call (gf args generalizers) + (multiple-value-bind (emf cacheablep) + (slow-method-lookup gf args generalizers) + (when cacheablep + (let ((keys (mapcar (lambda (x) (generalizer-equal-hash-key gf x)) generalizers))) + (if (first-arg-only-special-case gf) + (setf (gethash (car keys) (emf-table gf)) emf) + (setf (gethash keys (emf-table gf)) emf)))) + (sb-pcl::invoke-emf emf args))) + +(defun compute-effective-method-function (gf methods) + (if (null methods) + (lambda (&rest args) (apply #'no-applicable-method gf args)) + (let* ((mc (sb-mop:generic-function-method-combination gf)) + (sb-pcl::*applicable-methods* methods) + (em (sb-mop:compute-effective-method gf mc methods))) + (sb-pcl::make-effective-method-function gf em)))) + +;; new, not in closette +(defgeneric generalizer-of-using-class (generic-function object)) +(defmethod generalizer-of-using-class ((generic-function specializable-generic-function) object) + (class-of object)) + +(defgeneric specializer-accepts-generalizer-p (gf specializer generalizer)) +(defmethod specializer-accepts-generalizer-p + ((gf specializable-generic-function) (specializer class) (generalizer class)) + (if (subtypep generalizer specializer) + (values t t) + (values nil t))) +(defmethod specializer-accepts-generalizer-p + ((gf specializable-generic-function) (specializer sb-mop:eql-specializer) (generalizer class)) + (if (eq generalizer (class-of (sb-mop:eql-specializer-object specializer))) + (values t nil) + (values nil t))) + +(defgeneric compute-applicable-methods-using-generalizers (gf generalizers)) +(defmethod compute-applicable-methods-using-generalizers + ((gf specializable-generic-function) generalizers) + ;; differs from closette + (let ((result-definitive-p t)) + (flet ((filter (method) + (every (lambda (s g) + (multiple-value-bind (acceptsp definitivep) + (specializer-accepts-generalizer-p gf s g) + (unless definitivep + (setf result-definitive-p nil)) + acceptsp)) + (sb-mop:method-specializers method) generalizers)) + (sorter (m1 m2) + (method-more-specific-p gf m1 m2 generalizers))) + (values + (sort + (copy-list (remove-if-not #'filter (sb-mop:generic-function-methods gf))) + #'sorter) + result-definitive-p)))) + +;; new, not in closette +(defgeneric specializer-accepts-p (specializer object)) +(defmethod specializer-accepts-p ((specializer class) object) + (typep object specializer)) +(defmethod specializer-accepts-p ((specializer sb-mop:eql-specializer) object) + (eq object (sb-mop:eql-specializer-object specializer))) + +(defmethod compute-applicable-methods + ((gf specializable-generic-function) arguments) + ;; new, not in closette + (sort + (copy-list + (remove-if-not #'(lambda (method) + (every #'specializer-accepts-p + (sb-mop:method-specializers method) + arguments)) + (sb-mop:generic-function-methods gf))) + (let ((generalizers (mapcar (lambda (x) (generalizer-of-using-class gf x)) + (required-portion gf arguments)))) + (lambda (m1 m2) + (method-more-specific-p gf m1 m2 generalizers))))) + +(defun method-more-specific-p (gf method1 method2 generalizers) + ;; FIXME: argument precedence order + (block nil + (mapc #'(lambda (spec1 spec2 generalizer) + (ecase (specializer< gf spec1 spec2 generalizer) + (< (return t)) + (=) + ((nil > /=) (return nil)))) + (sb-mop:method-specializers method1) + (sb-mop:method-specializers method2) + generalizers) + nil)) + +;; new, not in closette +(defgeneric specializer< (gf s1 s2 generalizer)) +(defmethod specializer< + ((gf specializable-generic-function) (s1 class) (s2 class) (generalizer class)) + (if (eq s1 s2) + '= + (let ((cpl (sb-mop:class-precedence-list generalizer))) + (if (find s2 (cdr (member s1 cpl))) + '< + '>)))) +(defmethod specializer< + ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 sb-mop:eql-specializer) generalizer) + (declare (ignore generalizer)) + (if (eq (sb-mop:eql-specializer-object s1) (sb-mop:eql-specializer-object s2)) + '= + nil)) +(defmethod specializer< ((gf specializable-generic-function) (s1 sb-mop:eql-specializer) (s2 class) generalizer) + (declare (ignore generalizer)) + '<) +(defmethod specializer< ((gf specializable-generic-function) (c1 class) (c2 sb-mop:eql-specializer) generalizer) + (declare (ignore generalizer)) + '>)