mop: Handy function for making modified copies of instances.

[lisp] / mdw-mop.lisp

diff --git a/mdw-mop.lisp b/mdw-mop.lisp
index 0766e384cd7968e134a57efc06ffdf23b7d015a7..a6694903d24088f55d27c43dc818abb2bb14e908 100644 (file)
--- a/mdw-mop.lisp
+++ b/mdw-mop.lisp
@@ -27,8 +27,9 @@
 ;;; Packages.
 
 (defpackage #:mdw.mop
-  (:use #:common-lisp #+cmu #:pcl)
+  (:use #:common-lisp #:mdw.base #+cmu #:pcl)
   (:export #:compatible-class
+          #:copy-instance #:copy-instance-using-class
           #:initargs-for-effective-slot #:make-effective-slot
           #:filtered-slot-class-mixin
             #:filtered-direct-slot-definition
@@ -62,6 +63,27 @@ (defmethod validate-superclass
     ((sub standard-class) (super compatible-class))
   (eq (class-of sub) (find-class 'standard-class)))
 
+;;;--------------------------------------------------------------------------
+;;; Copying instances.
+
+(defgeneric copy-instance-using-class (class object &rest initargs)
+  (:documentation
+   "Does the donkey-work behind copy-instance."))
+
+(defmethod copy-instance-using-class
+    ((class standard-class) object &rest initargs)
+  (let ((new (apply #'allocate-instance class initargs)))
+    (dolist (slot (class-slots class))
+      (setf (slot-value-using-class class new slot)
+           (slot-value-using-class class object slot)))
+    (apply #'shared-initialize new nil initargs)
+    new))
+
+(defun copy-instance (object &rest initargs)
+  "Make a copy of OBJECT, modifying it by setting slots as requested by
+   INITARGS."
+  (apply #'copy-instance-using-class (class-of object) object initargs))
+
 ;;;--------------------------------------------------------------------------
 ;;; Utilities for messing with slot options.
 
@@ -152,7 +174,7 @@ (defmethod effective-slot-definition-class
       (call-next-method)))
 
 (defmethod initialize-instance :after
-    ((slot filtered-direct-slot-definition) &key &allow-other-keys)
+    ((slot filtered-direct-slot-definition) &key)
   (with-slots (filter) slot
     (when (and (consp filter)
               (or (eq (car filter) 'function)
@@ -191,7 +213,7 @@ (defclass predicate-class-mixin (compatible-class)
     returning a non-nil value."))
 
 (defmethod shared-initialize :after
-    ((class predicate-class-mixin) slot-names &key &allow-other-keys)
+    ((class predicate-class-mixin) slot-names &key)
   (declare (ignore slot-names))
   (with-slots (predicates) class
     (dolist (predicate predicates)
@@ -274,7 +296,7 @@ (defun print-object-with-slots (obj stream)
                 (progn (format stream " ~@_~:I") (setf sep t)))
             (let ((name (pprint-pop))
                   (value (pprint-pop)))
-              (format stream "~S ~@_~:[~S~;<unbound>~*~]"
+              (format stream "~S ~@_~:[~W~;#<unbound>~*~]"
                       name (eq value magic) value))))))))
 
 ;;;----- That's all, folks --------------------------------------------------