X-Git-Url: http://christophe.rhodes.io/gitweb/?p=specializable.git;a=blobdiff_plain;f=examples%2Fcons-specializer.lisp;fp=examples%2Fcons-specializer.lisp;h=38be99d129176cf17d711b5507706e23b50aed3e;hp=0000000000000000000000000000000000000000;hb=9dd8f1378407cae8ec7b6b05a8b3c152bc4a5f9b;hpb=d55ebbbcbd77023c799d8d95dce5d3772aec5841

diff --git a/examples/cons-specializer.lisp b/examples/cons-specializer.lisp
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+(in-package "SPECIALIZABLE")
+
+;;;; CONS-SPECIALIZER example
+(defclass cons-specializer (extended-specializer)
+  ((car :initarg :car :reader %car)))
+(defclass cons-generic-function (specializable-generic-function)
+  ()
+  (:metaclass sb-mop:funcallable-standard-class))
+
+(define-extended-specializer cons (gf car)
+  (make-instance 'cons-specializer :car car))
+(defmethod sb-pcl:unparse-specializer-using-class
+    ((gf cons-generic-function) (specializer cons-specializer))
+  `(cons ,(%car specializer)))
+(defmethod sb-pcl::same-specializer-p
+    ((s1 cons-specializer) (s2 cons-specializer))
+  (eql (%car s1) (%car s2)))
+
+;;; FIXME: make a proper generalizer
+(defmethod generalizer-equal-hash-key ((gf cons-generic-function) (g symbol))
+  g)
+(defmethod generalizer-of-using-class ((gf cons-generic-function) arg)
+  (typecase arg
+    ((cons symbol) (car arg))
+    (t (call-next-method))))
+(defmethod specializer-accepts-generalizer-p ((gf cons-generic-function) (specializer cons-specializer) thing)
+  (if (eql (%car specializer) thing)
+      (values t t)
+      (values nil t)))
+(defmethod specializer-accepts-generalizer-p ((gf cons-generic-function) (specializer sb-mop:specializer) (thing symbol))
+  (specializer-accepts-generalizer-p gf specializer (find-class 'cons)))
+
+;;; note: this method operates in full knowledge of the object, and so
+;;; does not require the generic function as an argument.
+(defmethod specializer-accepts-p ((specializer cons-specializer) obj)
+  (and (consp obj)
+       (eql (car obj) (%car specializer))))
+
+(defmethod specializer< ((gf cons-generic-function) (s1 cons-specializer) (s2 cons-specializer) generalizer)
+  (declare (ignore generalizer))
+  (if (eql (%car s1) (%car s2))
+      '=
+      nil))
+(defmethod specializer< ((gf cons-generic-function) (s1 cons-specializer) (s2 class) generalizer)
+  (declare (ignore generalizer))
+  '<)
+(defmethod specializer< ((gf cons-generic-function) (s1 cons-specializer) (s2 sb-mop:eql-specializer) generalizer)
+  (declare (ignore generalizer))
+  '>)
+(defmethod specializer< ((gf cons-generic-function) (s1 sb-mop:specializer) (s2 cons-specializer) generalizer)
+  (ecase (specializer< gf s2 s1 generalizer)
+    ((<) '>)
+    ((>) '<)))
+;;; note: the need for this method is tricky: we need to translate
+;;; from generalizers that our specializers "know" about to those that
+;;; ordinary generic functions and specializers might know about.
+(defmethod specializer< ((gf cons-generic-function) (s1 sb-mop:specializer) (s2 sb-mop:specializer) (generalizer symbol))
+  (specializer< gf s1 s2 (find-class 'cons)))
+
+;;; tests / examples
+(eval
+ '(progn
+   (defgeneric walk (form)
+     (:generic-function-class cons-generic-function))
+   (defmethod walk ((form symbol))
+     `(lookup ,form))
+   (defmethod walk ((form cons))
+     `(call (flookup ,(car form)) (list ,@(mapcar #'walk (cdr form)))))
+   (defmethod walk ((form (cons quote)))
+     (cadr form))
+   (defmethod walk ((form (cons let)))
+     (let ((bindings (cadr form)))
+       `(with-bindings ,bindings ,@(mapcar #'walk (cddr form)))))
+
+   (assert (equal (walk t) '(lookup t)))
+   (assert (equal (walk nil) '(lookup nil)))
+   (assert (equal (walk '(foo bar)) '(call (flookup foo) (list (lookup bar)))))
+   (assert (equal (walk '(quote bar)) 'bar))
+   (assert (equal (walk '(let foo bar)) '(with-bindings foo (lookup bar))))))
+
+(eval
+ '(progn
+   (defgeneric multiple-class-specializers (x)
+     (:generic-function-class cons-generic-function)
+     (:method-combination list))
+   (defmethod multiple-class-specializers list ((x t)) 't)
+   (defmethod multiple-class-specializers list ((x cons)) 'cons)
+   (defmethod multiple-class-specializers list ((x (cons foo))) '(cons foo))
+   (defmethod multiple-class-specializers list ((x (cons bar))) '(cons bar))
+   (defmethod multiple-class-specializers list ((x list)) 'list)
+   (defmethod multiple-class-specializers list ((x null)) 'null)
+   (defmethod multiple-class-specializers list ((x (eql nil))) '(eql nil))
+
+   (assert (equal (multiple-class-specializers nil) '((eql nil) null list t)))
+   (assert (equal (multiple-class-specializers t) '(t)))
+   (assert (equal (multiple-class-specializers (cons nil nil)) '(cons list t)))
+   (assert (equal (multiple-class-specializers (cons 'foo nil)) '((cons foo) cons list t)))
+   (assert (equal (multiple-class-specializers (list 'bar nil t 3)) '((cons bar) cons list t)))))
+
+(eval
+ '(progn
+   (defgeneric keyword-args (x &key key1)
+     (:generic-function-class cons-generic-function))
+   (defmethod keyword-args ((x integer) &key key1 key2) (1+ x))
+   (defmethod keyword-args ((x float) &key key1 key3) (+ x 2.0))
+   (defmethod keyword-args :after ((x double-float) &key &allow-other-keys)
+              nil)
+   (assert (= (keyword-args 1) 2))
+   (assert (= (keyword-args 1 :key1 t) 2))
+   (assert (= (keyword-args 1 :key2 t) 2))
+   (assert (= (keyword-args 1 :key1 t :key2 t) 2))
+   (assert (nth-value 1 (ignore-errors (keyword-args 1 :key1 t :key3 t))))
+   (assert (nth-value 1 (ignore-errors (keyword-args 1 :key3 t))))
+   (assert (= (keyword-args 1 :key3 t :allow-other-keys t) 2))
+
+   (assert (= (keyword-args 1.0) 3.0))
+   (assert (= (keyword-args 1.0 :key1 t) 3.0))
+   (assert (= (keyword-args 1.0 :key3 t) 3.0))
+   (assert (= (keyword-args 1.0 :key1 t :key3 t) 3.0))
+   (assert (nth-value 1 (ignore-errors (keyword-args 1.0 :key1 t :key2 t))))
+   (assert (nth-value 1 (ignore-errors (keyword-args 1.0 :key2 t))))
+   (assert (= (keyword-args 1.0 :key2 t :allow-other-keys t) 3.0))
+
+   (assert (= (keyword-args 1.0d0) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key1 t) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key3 t) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key1 t :key3 t) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key1 t :key2 t) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key2 t) 3.0d0))
+   (assert (= (keyword-args 1.0d0 :key2 t :allow-other-keys t) 3.0d0))))