;;;-*-Mode:LISP; Package: PCL; Base:10; Syntax:Common-lisp; Patch-File: Yes -*-
;;;
;;; *************************************************************************
;;; Copyright (c) 1985, 1986, 1987 Xerox Corporation. All rights reserved.
;;;
;;; Use and copying of this software and preparation of derivative works
;;; based upon this software are permitted. Any distribution of this
;;; software or derivative works must comply with all applicable United
;;; States export control laws.
;;;
;;; This software is made available AS IS, and Xerox Corporation makes no
;;; warranty about the software, its performance or its conformity to any
;;; specification.
;;;
;;; Any person obtaining a copy of this software is requested to send their
;;; name and post office or electronic mail address to:
;;; CommonLoops Coordinator
;;; Xerox Artifical Intelligence Systems
;;; 2400 Hanover St.
;;; Palo Alto, CA 94303
;;; (or send Arpanet mail to CommonLoops-Coordinator.pa@Xerox.arpa)
;;;
;;; Suggestions, comments and requests for improvements are also welcome.
;;; *************************************************************************
;;;
(in-package 'pcl)
(eval-when (compile load eval)
(fix-early-generic-functions))
;;
;;;;;; Pending defmeths which I couldn't do before.
;;
(eval-when (load eval)
(setf (symbol-function 'print-instance)
(symbol-function 'print-object)))
;;
;;;;;;
;;
(define-method-body-macro call-next-method ()
:global :error
:method (expand-call-next-method
(macroexpand-time-method macroexpand-time-environment)
nil
macroexpand-time-environment))
(defmethod expand-call-next-method ((mex-method standard-method) args mti)
(declare (ignore args))
(let* ((arglist (method-arglist mex-method))
(uid (macroexpand-time-method-uid mti))
(applyp nil))
(multiple-value-setq (arglist applyp) (make-call-arguments arglist))
(cond ((null (method-type-specifiers mex-method))
(warn "Using call-next-method in a default method.~%~
At run time this will generate an error.")
`(error "Using call-next-method in a default method."))
(applyp
`(apply #'call-next-method-internal ,uid . ,arglist))
(t
`(call-next-method-internal ,uid . ,arglist)))))
(defun call-next-method-internal (current-method &rest args)
(let* ((generic-function (method-generic-function current-method))
(type-specifiers (method-type-specifiers current-method))
(most-specific nil)
(most-specific-type-specifiers ())
(dispatch-order (slot-value--funcallable-standard-class
(class-of generic-function)
generic-function
'dispatch-order
nil
nil)))
(iterate ((method in (generic-function-methods generic-function)))
(let ((method-type-specifiers (method-type-specifiers method))
(temp ()))
(and (every #'(lambda (arg type-spec)
(or (eq type-spec 't)
(memq type-spec
(slot-value--class
(class-of arg) 'class-precedence-list))))
args method-type-specifiers)
(eql 1 (setq temp (compare-type-specifier-lists
type-specifiers
method-type-specifiers
()
args
()
dispatch-order)))
(or (null most-specific)
(eql 1 (setq temp (compare-type-specifier-lists
method-type-specifiers
most-specific-type-specifiers
()
args
()
dispatch-order))))
(setq most-specific method
most-specific-type-specifiers method-type-specifiers))))
(if (or most-specific
(setq most-specific (generic-function-default-method
generic-function)))
(apply (method-function most-specific) args)
(error "no super method found"))))
;;;
;;; This is kind of bozoid because it always copies the lambda-list even
;;; when it doesn't need to. It also doesn't remember things it could
;;; remember, causing it to call memq more than it should. Fix this one
;;; day when there is nothing else to do.
;;;
(defun make-call-arguments (lambda-list &aux applyp)
(setq lambda-list (reverse lambda-list))
(when (memq '&aux lambda-list)
(setq lambda-list (cdr (memq '&aux lambda-list))))
(setq lambda-list (nreverse lambda-list))
(let ((optional (memq '&optional lambda-list)))
(when optional
;; The &optional keyword appears in the lambda list.
;; Get rid of it, by moving the rest of the lambda list
;; up, then go through the optional arguments, replacing
;; them with the real symbol.
(setf (car optional) (cadr optional)
(cdr optional) (cddr optional))
(iterate ((loc on optional))
(when (memq (car loc) lambda-list-keywords)
(unless (memq (car loc) '(&rest &key &allow-other-keys))
(error
"The non-standard lambda list keyword ~S appeared in the~%~
lambda list of a method in which CALL-NEXT-METHOD is used.~%~
PCL can only deal with standard lambda list keywords."))
(when (listp (car loc)) (setf (car loc) (caar loc)))))))
(let ((rest (memq '&rest lambda-list)))
(cond ((not (null rest))
;; &rest appears in the lambda list. This means we
;; have to do an apply. We ignore the rest of the
;; lambda list, just grab the &rest var and set applyp.
(setf (car rest) (if (listp (cadr rest))
(caadr rest)
(cadr rest))
(cdr rest) ())
(setq applyp t))
(t
(let ((key (memq '&key lambda-list)))
(when key
;; &key appears in the lambda list. Remove &key from the
;; lambda list then replace all the keywords with pairs of
;; the actual keyword followed by the value variable.
;; Have to parse the hairy triple case of &key.
(let ((key-args
(iterate ((arg in (cdr key)))
(until (eq arg '&allow-other-keys))
(cond ((symbolp arg)
(collect (make-keyword arg))
(collect arg))
((cddr arg)
(collect (caddr arg))
(collect (car arg)))
(t
(collect (make-keyword (car arg)))
(collect (car arg)))))))
(if key-args
(setf (car key) (car key-args)
(cdr key) (cdr key-args))
(setf (cdr key) nil
lambda-list (remove '&key lambda-list)))))))))
(values lambda-list applyp))