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+;;; installed-scm-file
+
+;;;; Copyright (C) 1998,1999,2000,2001,2002, 2003, 2006 Free Software Foundation, Inc.
+;;;;
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 2.1 of the License, or (at your option) any later version.
+;;;;
+;;;; This library is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;;;; Lesser General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;;;;
+
+
+;;;; This software is a derivative work of other copyrighted softwares; the
+;;;; copyright notices of these softwares are placed in the file COPYRIGHTS
+;;;;
+;;;; This file is based upon stklos.stk from the STk distribution by
+;;;; Erick Gallesio <eg@unice.fr>.
+;;;;
+
+(define-module (oop goops)
+ :use-module (srfi srfi-1)
+ :export-syntax (define-class class standard-define-class
+ define-generic define-accessor define-method
+ define-extended-generic define-extended-generics
+ method)
+ :export (goops-version is-a? class-of
+ ensure-metaclass ensure-metaclass-with-supers
+ make-class
+ make-generic ensure-generic
+ make-extended-generic
+ make-accessor ensure-accessor
+ make-method add-method!
+ object-eqv? object-equal?
+ class-slot-ref class-slot-set! slot-unbound slot-missing
+ slot-definition-name slot-definition-options
+ slot-definition-allocation
+ slot-definition-getter slot-definition-setter
+ slot-definition-accessor
+ slot-definition-init-value slot-definition-init-form
+ slot-definition-init-thunk slot-definition-init-keyword
+ slot-init-function class-slot-definition
+ method-source
+ compute-cpl compute-std-cpl compute-get-n-set compute-slots
+ compute-getter-method compute-setter-method
+ allocate-instance initialize make-instance make
+ no-next-method no-applicable-method no-method
+ change-class update-instance-for-different-class
+ shallow-clone deep-clone
+ class-redefinition
+ apply-generic apply-method apply-methods
+ compute-applicable-methods %compute-applicable-methods
+ method-more-specific? sort-applicable-methods
+ class-subclasses class-methods
+ goops-error
+ min-fixnum max-fixnum
+ ;;; *fixme* Should go into goops.c
+ instance? slot-ref-using-class
+ slot-set-using-class! slot-bound-using-class?
+ slot-exists-using-class? slot-ref slot-set! slot-bound?
+ class-name class-direct-supers class-direct-subclasses
+ class-direct-methods class-direct-slots class-precedence-list
+ class-slots class-environment
+ generic-function-name
+ generic-function-methods method-generic-function method-specializers
+ primitive-generic-generic enable-primitive-generic!
+ method-procedure accessor-method-slot-definition
+ slot-exists? make find-method get-keyword)
+ :replace (<class> <operator-class> <entity-class> <entity>)
+ :no-backtrace)
+
+(define *goops-module* (current-module))
+
+;; First initialize the builtin part of GOOPS
+(eval-case
+ ((load-toplevel compile-toplevel)
+ (%init-goops-builtins)))
+
+;; Then load the rest of GOOPS
+(use-modules (oop goops util)
+ (oop goops dispatch)
+ (oop goops compile))
+
+
+(define min-fixnum (- (expt 2 29)))
+
+(define max-fixnum (- (expt 2 29) 1))
+
+;;
+;; goops-error
+;;
+(define (goops-error format-string . args)
+ (save-stack)
+ (scm-error 'goops-error #f format-string args '()))
+
+;;
+;; is-a?
+;;
+(define (is-a? obj class)
+ (and (memq class (class-precedence-list (class-of obj))) #t))
+
+
+;;;
+;;; {Meta classes}
+;;;
+
+(define ensure-metaclass-with-supers
+ (let ((table-of-metas '()))
+ (lambda (meta-supers)
+ (let ((entry (assoc meta-supers table-of-metas)))
+ (if entry
+ ;; Found a previously created metaclass
+ (cdr entry)
+ ;; Create a new meta-class which inherit from "meta-supers"
+ (let ((new (make <class> #:dsupers meta-supers
+ #:slots '()
+ #:name (gensym "metaclass"))))
+ (set! table-of-metas (cons (cons meta-supers new) table-of-metas))
+ new))))))
+
+(define (ensure-metaclass supers env)
+ (if (null? supers)
+ <class>
+ (let* ((all-metas (map (lambda (x) (class-of x)) supers))
+ (all-cpls (apply append
+ (map (lambda (m)
+ (cdr (class-precedence-list m)))
+ all-metas)))
+ (needed-metas '()))
+ ;; Find the most specific metaclasses. The new metaclass will be
+ ;; a subclass of these.
+ (for-each
+ (lambda (meta)
+ (if (and (not (member meta all-cpls))
+ (not (member meta needed-metas)))
+ (set! needed-metas (append needed-metas (list meta)))))
+ all-metas)
+ ;; Now return a subclass of the metaclasses we found.
+ (if (null? (cdr needed-metas))
+ (car needed-metas) ; If there's only one, just use it.
+ (ensure-metaclass-with-supers needed-metas)))))
+
+;;;
+;;; {Classes}
+;;;
+
+;;; (define-class NAME (SUPER ...) SLOT-DEFINITION ... OPTION ...)
+;;;
+;;; SLOT-DEFINITION ::= SLOT-NAME | (SLOT-NAME OPTION ...)
+;;; OPTION ::= KEYWORD VALUE
+;;;
+(define (define-class-pre-definition kw val)
+ (case kw
+ ((#:getter #:setter)
+ `(if (or (not (defined? ',val))
+ (not (is-a? ,val <generic>)))
+ (define-generic ,val)))
+ ((#:accessor)
+ `(if (or (not (defined? ',val))
+ (not (is-a? ,val <accessor>)))
+ (define-accessor ,val)))
+ (else #f)))
+
+(define (kw-do-map mapper f kwargs)
+ (define (keywords l)
+ (cond
+ ((null? l) '())
+ ((or (null? (cdr l)) (not (keyword? (car l))))
+ (goops-error "malformed keyword arguments: ~a" kwargs))
+ (else (cons (car l) (keywords (cddr l))))))
+ (define (args l)
+ (if (null? l) '() (cons (cadr l) (args (cddr l)))))
+ ;; let* to check keywords first
+ (let* ((k (keywords kwargs))
+ (a (args kwargs)))
+ (mapper f k a)))
+
+;;; This code should be implemented in C.
+;;;
+(define-macro (define-class name supers . slots)
+ ;; Some slot options require extra definitions to be made. In
+ ;; particular, we want to make sure that the generic function objects
+ ;; which represent accessors exist before `make-class' tries to add
+ ;; methods to them.
+ ;;
+ ;; Postpone some error handling to class macro.
+ ;;
+ `(begin
+ ;; define accessors
+ ,@(append-map (lambda (slot)
+ (kw-do-map filter-map
+ define-class-pre-definition
+ (if (pair? slot) (cdr slot) '())))
+ (take-while (lambda (x) (not (keyword? x))) slots))
+ (if (and (defined? ',name)
+ (is-a? ,name <class>)
+ (memq <object> (class-precedence-list ,name)))
+ (class-redefinition ,name
+ (class ,supers ,@slots #:name ',name))
+ (define ,name (class ,supers ,@slots #:name ',name)))))
+
+(define standard-define-class define-class)
+
+;;; (class (SUPER ...) SLOT-DEFINITION ... OPTION ...)
+;;;
+;;; SLOT-DEFINITION ::= SLOT-NAME | (SLOT-NAME OPTION ...)
+;;; OPTION ::= KEYWORD VALUE
+;;;
+(define-macro (class supers . slots)
+ (define (make-slot-definition-forms slots)
+ (map
+ (lambda (def)
+ (cond
+ ((pair? def)
+ `(list ',(car def)
+ ,@(kw-do-map append-map
+ (lambda (kw arg)
+ (case kw
+ ((#:init-form)
+ `(#:init-form ',arg
+ #:init-thunk (lambda () ,arg)))
+ (else (list kw arg))))
+ (cdr def))))
+ (else
+ `(list ',def))))
+ slots))
+
+ (if (not (list? supers))
+ (goops-error "malformed superclass list: ~S" supers))
+ (let ((slot-defs (cons #f '()))
+ (slots (take-while (lambda (x) (not (keyword? x))) slots))
+ (options (or (find-tail keyword? slots) '())))
+ `(make-class
+ ;; evaluate super class variables
+ (list ,@supers)
+ ;; evaluate slot definitions, except the slot name!
+ (list ,@(make-slot-definition-forms slots))
+ ;; evaluate class options
+ ,@options)))
+
+(define (make-class supers slots . options)
+ (let ((env (or (get-keyword #:environment options #f)
+ (top-level-env))))
+ (let* ((name (get-keyword #:name options (make-unbound)))
+ (supers (if (not (or-map (lambda (class)
+ (memq <object>
+ (class-precedence-list class)))
+ supers))
+ (append supers (list <object>))
+ supers))
+ (metaclass (or (get-keyword #:metaclass options #f)
+ (ensure-metaclass supers env))))
+
+ ;; Verify that all direct slots are different and that we don't inherit
+ ;; several time from the same class
+ (let ((tmp1 (find-duplicate supers))
+ (tmp2 (find-duplicate (map slot-definition-name slots))))
+ (if tmp1
+ (goops-error "make-class: super class ~S is duplicate in class ~S"
+ tmp1 name))
+ (if tmp2
+ (goops-error "make-class: slot ~S is duplicate in class ~S"
+ tmp2 name)))
+
+ ;; Everything seems correct, build the class
+ (apply make metaclass
+ #:dsupers supers
+ #:slots slots
+ #:name name
+ #:environment env
+ options))))
+
+;;;
+;;; {Generic functions and accessors}
+;;;
+
+;; Apparently the desired semantics are that we extend previous
+;; procedural definitions, but that if `name' was already a generic, we
+;; overwrite its definition.
+(define-macro (define-generic name)
+ (if (not (symbol? name))
+ (goops-error "bad generic function name: ~S" name))
+ `(define ,name
+ (if (and (defined? ',name) (is-a? ,name <generic>))
+ (make <generic> #:name ',name)
+ (ensure-generic (if (defined? ',name) ,name #f) ',name))))
+
+(define-macro (define-extended-generic name val)
+ (if (not (symbol? name))
+ (goops-error "bad generic function name: ~S" name))
+ `(define ,name (make-extended-generic ,val ',name)))
+
+(define-macro (define-extended-generics names . args)
+ (let ((prefixes (get-keyword #:prefix args #f)))
+ (if prefixes
+ `(begin
+ ,@(map (lambda (name)
+ `(define-extended-generic ,name
+ (list ,@(map (lambda (prefix)
+ (symbol-append prefix name))
+ prefixes))))
+ names))
+ (goops-error "no prefixes supplied"))))
+
+(define (make-generic . name)
+ (let ((name (and (pair? name) (car name))))
+ (make <generic> #:name name)))
+
+(define (make-extended-generic gfs . name)
+ (let* ((name (and (pair? name) (car name)))
+ (gfs (if (pair? gfs) gfs (list gfs)))
+ (gws? (any (lambda (gf) (is-a? gf <generic-with-setter>)) gfs)))
+ (let ((ans (if gws?
+ (let* ((sname (and name (make-setter-name name)))
+ (setters
+ (apply append
+ (map (lambda (gf)
+ (if (is-a? gf <generic-with-setter>)
+ (list (ensure-generic (setter gf)
+ sname))
+ '()))
+ gfs)))
+ (es (make <extended-generic-with-setter>
+ #:name name
+ #:extends gfs
+ #:setter (make <extended-generic>
+ #:name sname
+ #:extends setters))))
+ (extended-by! setters (setter es))
+ es)
+ (make <extended-generic>
+ #:name name
+ #:extends gfs))))
+ (extended-by! gfs ans)
+ ans)))
+
+(define (extended-by! gfs eg)
+ (for-each (lambda (gf)
+ (slot-set! gf 'extended-by
+ (cons eg (slot-ref gf 'extended-by))))
+ gfs))
+
+(define (not-extended-by! gfs eg)
+ (for-each (lambda (gf)
+ (slot-set! gf 'extended-by
+ (delq! eg (slot-ref gf 'extended-by))))
+ gfs))
+
+(define (ensure-generic old-definition . name)
+ (let ((name (and (pair? name) (car name))))
+ (cond ((is-a? old-definition <generic>) old-definition)
+ ((procedure-with-setter? old-definition)
+ (make <generic-with-setter>
+ #:name name
+ #:default (procedure old-definition)
+ #:setter (setter old-definition)))
+ ((procedure? old-definition)
+ (make <generic> #:name name #:default old-definition))
+ (else (make <generic> #:name name)))))
+
+;; same semantics as <generic>
+(define-macro (define-accessor name)
+ (if (not (symbol? name))
+ (goops-error "bad accessor name: ~S" name))
+ `(define ,name
+ (if (and (defined? ',name) (is-a? ,name <accessor>))
+ (make <accessor> #:name ',name)
+ (ensure-accessor (if (defined? ',name) ,name #f) ',name))))
+
+(define (make-setter-name name)
+ (string->symbol (string-append "setter:" (symbol->string name))))
+
+(define (make-accessor . name)
+ (let ((name (and (pair? name) (car name))))
+ (make <accessor>
+ #:name name
+ #:setter (make <generic>
+ #:name (and name (make-setter-name name))))))
+
+(define (ensure-accessor proc . name)
+ (let ((name (and (pair? name) (car name))))
+ (cond ((and (is-a? proc <accessor>)
+ (is-a? (setter proc) <generic>))
+ proc)
+ ((is-a? proc <generic-with-setter>)
+ (upgrade-accessor proc (setter proc)))
+ ((is-a? proc <generic>)
+ (upgrade-accessor proc (make-generic name)))
+ ((procedure-with-setter? proc)
+ (make <accessor>
+ #:name name
+ #:default (procedure proc)
+ #:setter (ensure-generic (setter proc) name)))
+ ((procedure? proc)
+ (ensure-accessor (ensure-generic proc name) name))
+ (else
+ (make-accessor name)))))
+
+(define (upgrade-accessor generic setter)
+ (let ((methods (slot-ref generic 'methods))
+ (gws (make (if (is-a? generic <extended-generic>)
+ <extended-generic-with-setter>
+ <accessor>)
+ #:name (generic-function-name generic)
+ #:extended-by (slot-ref generic 'extended-by)
+ #:setter setter)))
+ (if (is-a? generic <extended-generic>)
+ (let ((gfs (slot-ref generic 'extends)))
+ (not-extended-by! gfs generic)
+ (slot-set! gws 'extends gfs)
+ (extended-by! gfs gws)))
+ ;; Steal old methods
+ (for-each (lambda (method)
+ (slot-set! method 'generic-function gws))
+ methods)
+ (slot-set! gws 'methods methods)
+ gws))
+
+;;;
+;;; {Methods}
+;;;
+
+(define-macro (define-method head . body)
+ (if (not (pair? head))
+ (goops-error "bad method head: ~S" head))
+ (let ((gf (car head)))
+ (cond ((and (pair? gf)
+ (eq? (car gf) 'setter)
+ (pair? (cdr gf))
+ (symbol? (cadr gf))
+ (null? (cddr gf)))
+ ;; named setter method
+ (let ((name (cadr gf)))
+ (cond ((not (symbol? name))
+ `(add-method! (setter ,name)
+ (method ,(cdr head) ,@body)))
+ (else
+ `(begin
+ (if (or (not (defined? ',name))
+ (not (is-a? ,name <accessor>)))
+ (define-accessor ,name))
+ (add-method! (setter ,name)
+ (method ,(cdr head) ,@body)))))))
+ ((not (symbol? gf))
+ `(add-method! ,gf (method ,(cdr head) ,@body)))
+ (else
+ `(begin
+ ;; FIXME: this code is how it always was, but it's quite
+ ;; cracky: it will only define the generic function if it
+ ;; was undefined before (ok), or *was defined to #f*. The
+ ;; latter is crack. But there are bootstrap issues about
+ ;; fixing this -- change it to (is-a? ,gf <generic>) and
+ ;; see.
+ (if (or (not (defined? ',gf))
+ (not ,gf))
+ (define-generic ,gf))
+ (add-method! ,gf
+ (method ,(cdr head) ,@body)))))))
+
+(define (make-method specializers procedure)
+ (make <method>
+ #:specializers specializers
+ #:procedure procedure))
+
+(define-macro (method args . body)
+ (letrec ((specializers
+ (lambda (ls)
+ (cond ((null? ls) (list (list 'quote '())))
+ ((pair? ls) (cons (if (pair? (car ls))
+ (cadar ls)
+ '<top>)
+ (specializers (cdr ls))))
+ (else '(<top>)))))
+ (formals
+ (lambda (ls)
+ (if (pair? ls)
+ (cons (if (pair? (car ls)) (caar ls) (car ls))
+ (formals (cdr ls)))
+ ls))))
+ `(make <method>
+ #:specializers (cons* ,@(specializers args))
+ #:formals ',(formals args)
+ #:body ',body
+ #:compile-env (compile-time-environment)
+ #:procedure (lambda ,(formals args)
+ ,@(if (null? body)
+ '(begin)
+ body)))))
+
+;;;
+;;; {add-method!}
+;;;
+
+(define (add-method-in-classes! m)
+ ;; Add method in all the classes which appears in its specializers list
+ (for-each* (lambda (x)
+ (let ((dm (class-direct-methods x)))
+ (if (not (memv m dm))
+ (slot-set! x 'direct-methods (cons m dm)))))
+ (method-specializers m)))
+
+(define (remove-method-in-classes! m)
+ ;; Remove method in all the classes which appears in its specializers list
+ (for-each* (lambda (x)
+ (slot-set! x
+ 'direct-methods
+ (delv! m (class-direct-methods x))))
+ (method-specializers m)))
+
+(define (compute-new-list-of-methods gf new)
+ (let ((new-spec (method-specializers new))
+ (methods (slot-ref gf 'methods)))
+ (let loop ((l methods))
+ (if (null? l)
+ (cons new methods)
+ (if (equal? (method-specializers (car l)) new-spec)
+ (begin
+ ;; This spec. list already exists. Remove old method from dependents
+ (remove-method-in-classes! (car l))
+ (set-car! l new)
+ methods)
+ (loop (cdr l)))))))
+
+(define internal-add-method!
+ (method ((gf <generic>) (m <method>))
+ (slot-set! m 'generic-function gf)
+ (slot-set! gf 'methods (compute-new-list-of-methods gf m))
+ (let ((specializers (slot-ref m 'specializers)))
+ (slot-set! gf 'n-specialized
+ (max (length* specializers)
+ (slot-ref gf 'n-specialized))))
+ (%invalidate-method-cache! gf)
+ (add-method-in-classes! m)
+ *unspecified*))
+
+(define-generic add-method!)
+
+((method-procedure internal-add-method!) add-method! internal-add-method!)
+
+(define-method (add-method! (proc <procedure>) (m <method>))
+ (if (generic-capability? proc)
+ (begin
+ (enable-primitive-generic! proc)
+ (add-method! proc m))
+ (next-method)))
+
+(define-method (add-method! (pg <primitive-generic>) (m <method>))
+ (add-method! (primitive-generic-generic pg) m))
+
+(define-method (add-method! obj (m <method>))
+ (goops-error "~S is not a valid generic function" obj))
+
+;;;
+;;; {Access to meta objects}
+;;;
+
+;;;
+;;; Methods
+;;;
+(define-method (method-source (m <method>))
+ (let* ((spec (map* class-name (slot-ref m 'specializers)))
+ (proc (procedure-source (slot-ref m 'procedure)))
+ (args (cadr proc))
+ (body (cddr proc)))
+ (cons 'method
+ (cons (map* list args spec)
+ body))))
+
+;;;
+;;; Slots
+;;;
+(define slot-definition-name car)
+
+(define slot-definition-options cdr)
+
+(define (slot-definition-allocation s)
+ (get-keyword #:allocation (cdr s) #:instance))
+
+(define (slot-definition-getter s)
+ (get-keyword #:getter (cdr s) #f))
+
+(define (slot-definition-setter s)
+ (get-keyword #:setter (cdr s) #f))
+
+(define (slot-definition-accessor s)
+ (get-keyword #:accessor (cdr s) #f))
+
+(define (slot-definition-init-value s)
+ ;; can be #f, so we can't use #f as non-value
+ (get-keyword #:init-value (cdr s) (make-unbound)))
+
+(define (slot-definition-init-form s)
+ (get-keyword #:init-form (cdr s) (make-unbound)))
+
+(define (slot-definition-init-thunk s)
+ (get-keyword #:init-thunk (cdr s) #f))
+
+(define (slot-definition-init-keyword s)
+ (get-keyword #:init-keyword (cdr s) #f))
+
+(define (class-slot-definition class slot-name)
+ (assq slot-name (class-slots class)))
+
+(define (slot-init-function class slot-name)
+ (cadr (assq slot-name (slot-ref class 'getters-n-setters))))
+
+
+;;;
+;;; {Standard methods used by the C runtime}
+;;;
+
+;;; Methods to compare objects
+;;;
+
+(define-method (eqv? x y) #f)
+(define-method (equal? x y) (eqv? x y))
+
+;;; These following two methods are for backward compatibility only.
+;;; They are not called by the Guile interpreter.
+;;;
+(define-method (object-eqv? x y) #f)
+(define-method (object-equal? x y) (eqv? x y))
+
+;;;
+;;; methods to display/write an object
+;;;
+
+; Code for writing objects must test that the slots they use are
+; bound. Otherwise a slot-unbound method will be called and will
+; conduct to an infinite loop.
+
+;; Write
+(define (display-address o file)
+ (display (number->string (object-address o) 16) file))
+
+(define-method (write o file)
+ (display "#<instance " file)
+ (display-address o file)
+ (display #\> file))
+
+(define write-object (primitive-generic-generic write))
+
+(define-method (write (o <object>) file)
+ (let ((class (class-of o)))
+ (if (slot-bound? class 'name)
+ (begin
+ (display "#<" file)
+ (display (class-name class) file)
+ (display #\space file)
+ (display-address o file)
+ (display #\> file))
+ (next-method))))
+
+(define-method (write (o <foreign-object>) file)
+ (let ((class (class-of o)))
+ (if (slot-bound? class 'name)
+ (begin
+ (display "#<foreign-object " file)
+ (display (class-name class) file)
+ (display #\space file)
+ (display-address o file)
+ (display #\> file))
+ (next-method))))
+
+(define-method (write (class <class>) file)
+ (let ((meta (class-of class)))
+ (if (and (slot-bound? class 'name)
+ (slot-bound? meta 'name))
+ (begin
+ (display "#<" file)
+ (display (class-name meta) file)
+ (display #\space file)
+ (display (class-name class) file)
+ (display #\space file)
+ (display-address class file)
+ (display #\> file))
+ (next-method))))
+
+(define-method (write (gf <generic>) file)
+ (let ((meta (class-of gf)))
+ (if (and (slot-bound? meta 'name)
+ (slot-bound? gf 'methods))
+ (begin
+ (display "#<" file)
+ (display (class-name meta) file)
+ (let ((name (generic-function-name gf)))
+ (if name
+ (begin
+ (display #\space file)
+ (display name file))))
+ (display " (" file)
+ (display (length (generic-function-methods gf)) file)
+ (display ")>" file))
+ (next-method))))
+
+(define-method (write (o <method>) file)
+ (let ((meta (class-of o)))
+ (if (and (slot-bound? meta 'name)
+ (slot-bound? o 'specializers))
+ (begin
+ (display "#<" file)
+ (display (class-name meta) file)
+ (display #\space file)
+ (display (map* (lambda (spec)
+ (if (slot-bound? spec 'name)
+ (slot-ref spec 'name)
+ spec))
+ (method-specializers o))
+ file)
+ (display #\space file)
+ (display-address o file)
+ (display #\> file))
+ (next-method))))
+
+;; Display (do the same thing as write by default)
+(define-method (display o file)
+ (write-object o file))
+
+;;;
+;;; Handling of duplicate bindings in the module system
+;;;
+
+(define-method (merge-generics (module <module>)
+ (name <symbol>)
+ (int1 <module>)
+ (val1 <top>)
+ (int2 <module>)
+ (val2 <top>)
+ (var <top>)
+ (val <top>))
+ #f)
+
+(define-method (merge-generics (module <module>)
+ (name <symbol>)
+ (int1 <module>)
+ (val1 <generic>)
+ (int2 <module>)
+ (val2 <generic>)
+ (var <top>)
+ (val <boolean>))
+ (and (not (eq? val1 val2))
+ (make-variable (make-extended-generic (list val2 val1) name))))
+
+(define-method (merge-generics (module <module>)
+ (name <symbol>)
+ (int1 <module>)
+ (val1 <generic>)
+ (int2 <module>)
+ (val2 <generic>)
+ (var <top>)
+ (gf <extended-generic>))
+ (and (not (memq val2 (slot-ref gf 'extends)))
+ (begin
+ (slot-set! gf
+ 'extends
+ (cons val2 (delq! val2 (slot-ref gf 'extends))))
+ (slot-set! val2
+ 'extended-by
+ (cons gf (delq! gf (slot-ref val2 'extended-by))))
+ var)))
+
+(module-define! duplicate-handlers 'merge-generics merge-generics)
+
+(define-method (merge-accessors (module <module>)
+ (name <symbol>)
+ (int1 <module>)
+ (val1 <top>)
+ (int2 <module>)
+ (val2 <top>)
+ (var <top>)
+ (val <top>))
+ #f)
+
+(define-method (merge-accessors (module <module>)
+ (name <symbol>)
+ (int1 <module>)
+ (val1 <accessor>)
+ (int2 <module>)
+ (val2 <accessor>)
+ (var <top>)
+ (val <top>))
+ (merge-generics module name int1 val1 int2 val2 var val))
+
+(module-define! duplicate-handlers 'merge-accessors merge-accessors)
+
+;;;
+;;; slot access
+;;;
+
+(define (class-slot-g-n-s class slot-name)
+ (let* ((this-slot (assq slot-name (slot-ref class 'slots)))
+ (g-n-s (cddr (or (assq slot-name (slot-ref class 'getters-n-setters))
+ (slot-missing class slot-name)))))
+ (if (not (memq (slot-definition-allocation this-slot)
+ '(#:class #:each-subclass)))
+ (slot-missing class slot-name))
+ g-n-s))
+
+(define (class-slot-ref class slot)
+ (let ((x ((car (class-slot-g-n-s class slot)) #f)))
+ (if (unbound? x)
+ (slot-unbound class slot)
+ x)))
+
+(define (class-slot-set! class slot value)
+ ((cadr (class-slot-g-n-s class slot)) #f value))
+
+(define-method (slot-unbound (c <class>) (o <object>) s)
+ (goops-error "Slot `~S' is unbound in object ~S" s o))
+
+(define-method (slot-unbound (c <class>) s)
+ (goops-error "Slot `~S' is unbound in class ~S" s c))
+
+(define-method (slot-unbound (o <object>))
+ (goops-error "Unbound slot in object ~S" o))
+
+(define-method (slot-missing (c <class>) (o <object>) s)
+ (goops-error "No slot with name `~S' in object ~S" s o))
+
+(define-method (slot-missing (c <class>) s)
+ (goops-error "No class slot with name `~S' in class ~S" s c))
+
+
+(define-method (slot-missing (c <class>) (o <object>) s value)
+ (slot-missing c o s))
+
+;;; Methods for the possible error we can encounter when calling a gf
+
+(define-method (no-next-method (gf <generic>) args)
+ (goops-error "No next method when calling ~S\nwith arguments ~S" gf args))
+
+(define-method (no-applicable-method (gf <generic>) args)
+ (goops-error "No applicable method for ~S in call ~S"
+ gf (cons (generic-function-name gf) args)))
+
+(define-method (no-method (gf <generic>) args)
+ (goops-error "No method defined for ~S" gf))
+
+;;;
+;;; {Cloning functions (from rdeline@CS.CMU.EDU)}
+;;;
+
+(define-method (shallow-clone (self <object>))
+ (let ((clone (%allocate-instance (class-of self) '()))
+ (slots (map slot-definition-name
+ (class-slots (class-of self)))))
+ (for-each (lambda (slot)
+ (if (slot-bound? self slot)
+ (slot-set! clone slot (slot-ref self slot))))
+ slots)
+ clone))
+
+(define-method (deep-clone (self <object>))
+ (let ((clone (%allocate-instance (class-of self) '()))
+ (slots (map slot-definition-name
+ (class-slots (class-of self)))))
+ (for-each (lambda (slot)
+ (if (slot-bound? self slot)
+ (slot-set! clone slot
+ (let ((value (slot-ref self slot)))
+ (if (instance? value)
+ (deep-clone value)
+ value)))))
+ slots)
+ clone))
+
+;;;
+;;; {Class redefinition utilities}
+;;;
+
+;;; (class-redefinition OLD NEW)
+;;;
+
+;;; Has correct the following conditions:
+
+;;; Methods
+;;;
+;;; 1. New accessor specializers refer to new header
+;;;
+;;; Classes
+;;;
+;;; 1. New class cpl refers to the new class header
+;;; 2. Old class header exists on old super classes direct-subclass lists
+;;; 3. New class header exists on new super classes direct-subclass lists
+
+(define-method (class-redefinition (old <class>) (new <class>))
+ ;; Work on direct methods:
+ ;; 1. Remove accessor methods from the old class
+ ;; 2. Patch the occurences of new in the specializers by old
+ ;; 3. Displace the methods from old to new
+ (remove-class-accessors! old) ;; -1-
+ (let ((methods (class-direct-methods new)))
+ (for-each (lambda (m)
+ (update-direct-method! m new old)) ;; -2-
+ methods)
+ (slot-set! new
+ 'direct-methods
+ (append methods (class-direct-methods old))))
+
+ ;; Substitute old for new in new cpl
+ (set-car! (slot-ref new 'cpl) old)
+
+ ;; Remove the old class from the direct-subclasses list of its super classes
+ (for-each (lambda (c) (slot-set! c 'direct-subclasses
+ (delv! old (class-direct-subclasses c))))
+ (class-direct-supers old))
+
+ ;; Replace the new class with the old in the direct-subclasses of the supers
+ (for-each (lambda (c)
+ (slot-set! c 'direct-subclasses
+ (cons old (delv! new (class-direct-subclasses c)))))
+ (class-direct-supers new))
+
+ ;; Swap object headers
+ (%modify-class old new)
+
+ ;; Now old is NEW!
+
+ ;; Redefine all the subclasses of old to take into account modification
+ (for-each
+ (lambda (c)
+ (update-direct-subclass! c new old))
+ (class-direct-subclasses new))
+
+ ;; Invalidate class so that subsequent instances slot accesses invoke
+ ;; change-object-class
+ (slot-set! new 'redefined old)
+ (%invalidate-class new) ;must come after slot-set!
+
+ old)
+
+;;;
+;;; remove-class-accessors!
+;;;
+
+(define-method (remove-class-accessors! (c <class>))
+ (for-each (lambda (m)
+ (if (is-a? m <accessor-method>)
+ (let ((gf (slot-ref m 'generic-function)))
+ ;; remove the method from its GF
+ (slot-set! gf 'methods
+ (delq1! m (slot-ref gf 'methods)))
+ (%invalidate-method-cache! gf)
+ ;; remove the method from its specializers
+ (remove-method-in-classes! m))))
+ (class-direct-methods c)))
+
+;;;
+;;; update-direct-method!
+;;;
+
+(define-method (update-direct-method! (m <method>)
+ (old <class>)
+ (new <class>))
+ (let loop ((l (method-specializers m)))
+ ;; Note: the <top> in dotted list is never used.
+ ;; So we can work as if we had only proper lists.
+ (if (pair? l)
+ (begin
+ (if (eqv? (car l) old)
+ (set-car! l new))
+ (loop (cdr l))))))
+
+;;;
+;;; update-direct-subclass!
+;;;
+
+(define-method (update-direct-subclass! (c <class>)
+ (old <class>)
+ (new <class>))
+ (class-redefinition c
+ (make-class (class-direct-supers c)
+ (class-direct-slots c)
+ #:name (class-name c)
+ #:environment (slot-ref c 'environment)
+ #:metaclass (class-of c))))
+
+;;;
+;;; {Utilities for INITIALIZE methods}
+;;;
+
+;;; compute-slot-accessors
+;;;
+(define (compute-slot-accessors class slots env)
+ (for-each
+ (lambda (s g-n-s)
+ (let ((name (slot-definition-name s))
+ (getter-function (slot-definition-getter s))
+ (setter-function (slot-definition-setter s))
+ (accessor (slot-definition-accessor s)))
+ (if getter-function
+ (add-method! getter-function
+ (compute-getter-method class g-n-s)))
+ (if setter-function
+ (add-method! setter-function
+ (compute-setter-method class g-n-s)))
+ (if accessor
+ (begin
+ (add-method! accessor
+ (compute-getter-method class g-n-s))
+ (add-method! (setter accessor)
+ (compute-setter-method class g-n-s))))))
+ slots (slot-ref class 'getters-n-setters)))
+
+(define-method (compute-getter-method (class <class>) slotdef)
+ (let ((init-thunk (cadr slotdef))
+ (g-n-s (cddr slotdef)))
+ (make <accessor-method>
+ #:specializers (list class)
+ #:procedure (cond ((pair? g-n-s)
+ (make-generic-bound-check-getter (car g-n-s)))
+ (init-thunk
+ (standard-get g-n-s))
+ (else
+ (bound-check-get g-n-s)))
+ #:slot-definition slotdef)))
+
+(define-method (compute-setter-method (class <class>) slotdef)
+ (let ((g-n-s (cddr slotdef)))
+ (make <accessor-method>
+ #:specializers (list class <top>)
+ #:procedure (if (pair? g-n-s)
+ (cadr g-n-s)
+ (standard-set g-n-s))
+ #:slot-definition slotdef)))
+
+(define (make-generic-bound-check-getter proc)
+ (let ((source (and (closure? proc) (procedure-source proc))))
+ (if (and source (null? (cdddr source)))
+ (let ((obj (caadr source)))
+ ;; smart closure compilation
+ (local-eval
+ `(lambda (,obj) (,assert-bound ,(caddr source) ,obj))
+ (procedure-environment proc)))
+ (lambda (o) (assert-bound (proc o) o)))))
+
+(define n-standard-accessor-methods 10)
+
+(define bound-check-get-methods (make-vector n-standard-accessor-methods #f))
+(define standard-get-methods (make-vector n-standard-accessor-methods #f))
+(define standard-set-methods (make-vector n-standard-accessor-methods #f))
+
+(define (standard-accessor-method make methods)
+ (lambda (index)
+ (cond ((>= index n-standard-accessor-methods) (make index))
+ ((vector-ref methods index))
+ (else (let ((m (make index)))
+ (vector-set! methods index m)
+ m)))))
+
+;; the idea is to compile the index into the procedure, for fastest
+;; lookup. Also, @slot-ref and @slot-set! have their own bytecodes.
+
+(eval-case
+ ((load-toplevel compile-toplevel)
+ (use-modules ((language scheme translate) :select (define-scheme-translator))
+ ((system il ghil) :select (make-ghil-inline))
+ (system base pmatch))
+
+ ;; unfortunately, can't use define-inline because these are primitive
+ ;; syntaxen.
+ (define-scheme-translator @slot-ref
+ ((,obj ,index) (guard (integer? index)
+ (>= index 0) (< index max-fixnum))
+ (make-ghil-inline #f #f 'slot-ref
+ (list (retrans obj) (retrans index)))))
+
+ (define-scheme-translator @slot-set!
+ ((,obj ,index ,val) (guard (integer? index)
+ (>= index 0) (< index max-fixnum))
+ (make-ghil-inline #f #f 'slot-set
+ (list (retrans obj) (retrans index) (retrans val)))))))
+
+;; Irritatingly, we can't use `compile' here, as the module shadows
+;; the binding.
+(define (make-bound-check-get index)
+ ((@ (system base compile) compile)
+ `(lambda (o) (let ((x (@slot-ref o ,index)))
+ (if (unbound? x)
+ (slot-unbound obj)
+ x)))
+ *goops-module*))
+
+(define (make-get index)
+ ((@ (system base compile) compile)
+ `(lambda (o) (@slot-ref o ,index))
+ *goops-module*))
+
+(define (make-set index)
+ ((@ (system base compile) compile)
+ `(lambda (o v) (@slot-set! o ,index v))
+ *goops-module*))
+
+(define bound-check-get
+ (standard-accessor-method make-bound-check-get bound-check-get-methods))
+(define standard-get (standard-accessor-method make-get standard-get-methods))
+(define standard-set (standard-accessor-method make-set standard-set-methods))
+
+;;; compute-getters-n-setters
+;;;
+(define (make-thunk thunk)
+ (lambda () (thunk)))
+
+(define (compute-getters-n-setters class slots env)
+
+ (define (compute-slot-init-function name s)
+ (or (let ((thunk (slot-definition-init-thunk s)))
+ (and thunk
+ (cond ((not (thunk? thunk))
+ (goops-error "Bad init-thunk for slot `~S' in ~S: ~S"
+ name class thunk))
+ ((closure? thunk) thunk)
+ (else (make-thunk thunk)))))
+ (let ((init (slot-definition-init-value s)))
+ (and (not (unbound? init))
+ (lambda () init)))))
+
+ (define (verify-accessors slot l)
+ (cond ((integer? l))
+ ((not (and (list? l) (= (length l) 2)))
+ (goops-error "Bad getter and setter for slot `~S' in ~S: ~S"
+ slot class l))
+ (else
+ (let ((get (car l))
+ (set (cadr l)))
+ ;; note that we allow non-closures; we only check arity on
+ ;; the closures, though, because we inline their dispatch
+ ;; in %get-slot-value / %set-slot-value.
+ (if (or (not (procedure? get))
+ (and (closure? get)
+ (not (= (car (procedure-property get 'arity)) 1))))
+ (goops-error "Bad getter closure for slot `~S' in ~S: ~S"
+ slot class get))
+ (if (or (not (procedure? set))
+ (and (closure? set)
+ (not (= (car (procedure-property set 'arity)) 2))))
+ (goops-error "Bad setter closure for slot `~S' in ~S: ~S"
+ slot class set))))))
+
+ (map (lambda (s)
+ ;; The strange treatment of nfields is due to backward compatibility.
+ (let* ((index (slot-ref class 'nfields))
+ (g-n-s (compute-get-n-set class s))
+ (size (- (slot-ref class 'nfields) index))
+ (name (slot-definition-name s)))
+ ;; NOTE: The following is interdependent with C macros
+ ;; defined above goops.c:scm_sys_prep_layout_x.
+ ;;
+ ;; For simple instance slots, we have the simplest form
+ ;; '(name init-function . index)
+ ;; For other slots we have
+ ;; '(name init-function getter setter . alloc)
+ ;; where alloc is:
+ ;; '(index size) for instance allocated slots
+ ;; '() for other slots
+ (verify-accessors name g-n-s)
+ (cons name
+ (cons (compute-slot-init-function name s)
+ (if (or (integer? g-n-s)
+ (zero? size))
+ g-n-s
+ (append g-n-s (list index size)))))))
+ slots))
+
+;;; compute-cpl
+;;;
+;;; Correct behaviour:
+;;;
+;;; (define-class food ())
+;;; (define-class fruit (food))
+;;; (define-class spice (food))
+;;; (define-class apple (fruit))
+;;; (define-class cinnamon (spice))
+;;; (define-class pie (apple cinnamon))
+;;; => cpl (pie) = pie apple fruit cinnamon spice food object top
+;;;
+;;; (define-class d ())
+;;; (define-class e ())
+;;; (define-class f ())
+;;; (define-class b (d e))
+;;; (define-class c (e f))
+;;; (define-class a (b c))
+;;; => cpl (a) = a b d c e f object top
+;;;
+
+(define-method (compute-cpl (class <class>))
+ (compute-std-cpl class class-direct-supers))
+
+;; Support
+
+(define (only-non-null lst)
+ (filter (lambda (l) (not (null? l))) lst))
+
+(define (compute-std-cpl c get-direct-supers)
+ (let ((c-direct-supers (get-direct-supers c)))
+ (merge-lists (list c)
+ (only-non-null (append (map class-precedence-list
+ c-direct-supers)
+ (list c-direct-supers))))))
+
+(define (merge-lists reversed-partial-result inputs)
+ (cond
+ ((every null? inputs)
+ (reverse! reversed-partial-result))
+ (else
+ (let* ((candidate (lambda (c)
+ (and (not (any (lambda (l)
+ (memq c (cdr l)))
+ inputs))
+ c)))
+ (candidate-car (lambda (l)
+ (and (not (null? l))
+ (candidate (car l)))))
+ (next (any candidate-car inputs)))
+ (if (not next)
+ (goops-error "merge-lists: Inconsistent precedence graph"))
+ (let ((remove-next (lambda (l)
+ (if (eq? (car l) next)
+ (cdr l)
+ l))))
+ (merge-lists (cons next reversed-partial-result)
+ (only-non-null (map remove-next inputs))))))))
+
+;; Modified from TinyClos:
+;;
+;; A simple topological sort.
+;;
+;; It's in this file so that both TinyClos and Objects can use it.
+;;
+;; This is a fairly modified version of code I originally got from Anurag
+;; Mendhekar <anurag@moose.cs.indiana.edu>.
+;;
+
+(define (compute-clos-cpl c get-direct-supers)
+ (top-sort ((build-transitive-closure get-direct-supers) c)
+ ((build-constraints get-direct-supers) c)
+ (std-tie-breaker get-direct-supers)))
+
+
+(define (top-sort elements constraints tie-breaker)
+ (let loop ((elements elements)
+ (constraints constraints)
+ (result '()))
+ (if (null? elements)
+ result
+ (let ((can-go-in-now
+ (filter
+ (lambda (x)
+ (every (lambda (constraint)
+ (or (not (eq? (cadr constraint) x))
+ (memq (car constraint) result)))
+ constraints))
+ elements)))
+ (if (null? can-go-in-now)
+ (goops-error "top-sort: Invalid constraints")
+ (let ((choice (if (null? (cdr can-go-in-now))
+ (car can-go-in-now)
+ (tie-breaker result
+ can-go-in-now))))
+ (loop
+ (filter (lambda (x) (not (eq? x choice)))
+ elements)
+ constraints
+ (append result (list choice)))))))))
+
+(define (std-tie-breaker get-supers)
+ (lambda (partial-cpl min-elts)
+ (let loop ((pcpl (reverse partial-cpl)))
+ (let ((current-elt (car pcpl)))
+ (let ((ds-of-ce (get-supers current-elt)))
+ (let ((common (filter (lambda (x)
+ (memq x ds-of-ce))
+ min-elts)))
+ (if (null? common)
+ (if (null? (cdr pcpl))
+ (goops-error "std-tie-breaker: Nothing valid")
+ (loop (cdr pcpl)))
+ (car common))))))))
+
+
+(define (build-transitive-closure get-follow-ons)
+ (lambda (x)
+ (let track ((result '())
+ (pending (list x)))
+ (if (null? pending)
+ result
+ (let ((next (car pending)))
+ (if (memq next result)
+ (track result (cdr pending))
+ (track (cons next result)
+ (append (get-follow-ons next)
+ (cdr pending)))))))))
+
+(define (build-constraints get-follow-ons)
+ (lambda (x)
+ (let loop ((elements ((build-transitive-closure get-follow-ons) x))
+ (this-one '())
+ (result '()))
+ (if (or (null? this-one) (null? (cdr this-one)))
+ (if (null? elements)
+ result
+ (loop (cdr elements)
+ (cons (car elements)
+ (get-follow-ons (car elements)))
+ result))
+ (loop elements
+ (cdr this-one)
+ (cons (list (car this-one) (cadr this-one))
+ result))))))
+
+;;; compute-get-n-set
+;;;
+(define-method (compute-get-n-set (class <class>) s)
+ (case (slot-definition-allocation s)
+ ((#:instance) ;; Instance slot
+ ;; get-n-set is just its offset
+ (let ((already-allocated (slot-ref class 'nfields)))
+ (slot-set! class 'nfields (+ already-allocated 1))
+ already-allocated))
+
+ ((#:class) ;; Class slot
+ ;; Class-slots accessors are implemented as 2 closures around
+ ;; a Scheme variable. As instance slots, class slots must be
+ ;; unbound at init time.
+ (let ((name (slot-definition-name s)))
+ (if (memq name (map slot-definition-name (class-direct-slots class)))
+ ;; This slot is direct; create a new shared variable
+ (make-closure-variable class)
+ ;; Slot is inherited. Find its definition in superclass
+ (let loop ((l (cdr (class-precedence-list class))))
+ (let ((r (assoc name (slot-ref (car l) 'getters-n-setters))))
+ (if r
+ (cddr r)
+ (loop (cdr l))))))))
+
+ ((#:each-subclass) ;; slot shared by instances of direct subclass.
+ ;; (Thomas Buerger, April 1998)
+ (make-closure-variable class))
+
+ ((#:virtual) ;; No allocation
+ ;; slot-ref and slot-set! function must be given by the user
+ (let ((get (get-keyword #:slot-ref (slot-definition-options s) #f))
+ (set (get-keyword #:slot-set! (slot-definition-options s) #f))
+ (env (class-environment class)))
+ (if (not (and get set))
+ (goops-error "You must supply a #:slot-ref and a #:slot-set! in ~S"
+ s))
+ (list get set)))
+ (else (next-method))))
+
+(define (make-closure-variable class)
+ (let ((shared-variable (make-unbound)))
+ (list (lambda (o) shared-variable)
+ (lambda (o v) (set! shared-variable v)))))
+
+(define-method (compute-get-n-set (o <object>) s)
+ (goops-error "Allocation \"~S\" is unknown" (slot-definition-allocation s)))
+
+(define-method (compute-slots (class <class>))
+ (%compute-slots class))
+
+;;;
+;;; {Initialize}
+;;;
+
+(define-method (initialize (object <object>) initargs)
+ (%initialize-object object initargs))
+
+(define-method (initialize (class <class>) initargs)
+ (next-method)
+ (let ((dslots (get-keyword #:slots initargs '()))
+ (supers (get-keyword #:dsupers initargs '()))
+ (env (get-keyword #:environment initargs (top-level-env))))
+
+ (slot-set! class 'name (get-keyword #:name initargs '???))
+ (slot-set! class 'direct-supers supers)
+ (slot-set! class 'direct-slots dslots)
+ (slot-set! class 'direct-subclasses '())
+ (slot-set! class 'direct-methods '())
+ (slot-set! class 'cpl (compute-cpl class))
+ (slot-set! class 'redefined #f)
+ (slot-set! class 'environment env)
+ (let ((slots (compute-slots class)))
+ (slot-set! class 'slots slots)
+ (slot-set! class 'nfields 0)
+ (slot-set! class 'getters-n-setters (compute-getters-n-setters class
+ slots
+ env))
+ ;; Build getters - setters - accessors
+ (compute-slot-accessors class slots env))
+
+ ;; Update the "direct-subclasses" of each inherited classes
+ (for-each (lambda (x)
+ (slot-set! x
+ 'direct-subclasses
+ (cons class (slot-ref x 'direct-subclasses))))
+ supers)
+
+ ;; Support for the underlying structs:
+
+ ;; Inherit class flags (invisible on scheme level) from supers
+ (%inherit-magic! class supers)
+
+ ;; Set the layout slot
+ (%prep-layout! class)))
+
+(define (initialize-object-procedure object initargs)
+ (let ((proc (get-keyword #:procedure initargs #f)))
+ (cond ((not proc))
+ ((pair? proc)
+ (apply set-object-procedure! object proc))
+ ((valid-object-procedure? proc)
+ (set-object-procedure! object proc))
+ (else
+ (set-object-procedure! object
+ (lambda args (apply proc args)))))))
+
+(define-method (initialize (class <operator-class>) initargs)
+ (next-method)
+ (initialize-object-procedure class initargs))
+
+(define-method (initialize (owsc <operator-with-setter-class>) initargs)
+ (next-method)
+ (%set-object-setter! owsc (get-keyword #:setter initargs #f)))
+
+(define-method (initialize (entity <entity>) initargs)
+ (next-method)
+ (initialize-object-procedure entity initargs))
+
+(define-method (initialize (ews <entity-with-setter>) initargs)
+ (next-method)
+ (%set-object-setter! ews (get-keyword #:setter initargs #f)))
+
+(define-method (initialize (generic <generic>) initargs)
+ (let ((previous-definition (get-keyword #:default initargs #f))
+ (name (get-keyword #:name initargs #f)))
+ (next-method)
+ (slot-set! generic 'methods (if (is-a? previous-definition <procedure>)
+ (list (method args
+ (apply previous-definition args)))
+ '()))
+ (if name
+ (set-procedure-property! generic 'name name))
+ ))
+
+(define-method (initialize (eg <extended-generic>) initargs)
+ (next-method)
+ (slot-set! eg 'extends (get-keyword #:extends initargs '())))
+
+(define dummy-procedure (lambda args *unspecified*))
+
+(define-method (initialize (method <method>) initargs)
+ (next-method)
+ (slot-set! method 'generic-function (get-keyword #:generic-function initargs #f))
+ (slot-set! method 'specializers (get-keyword #:specializers initargs '()))
+ (slot-set! method 'procedure
+ (get-keyword #:procedure initargs dummy-procedure))
+ (slot-set! method 'code-table '())
+ (slot-set! method 'formals (get-keyword #:formals initargs '()))
+ (slot-set! method 'body (get-keyword #:body initargs '()))
+ (slot-set! method 'compile-env (get-keyword #:compile-env initargs #f)))
+
+
+(define-method (initialize (obj <foreign-object>) initargs))
+
+;;;
+;;; {Change-class}
+;;;
+
+(define (change-object-class old-instance old-class new-class)
+ (let ((new-instance (allocate-instance new-class '())))
+ ;; Initialize the slots of the new instance
+ (for-each (lambda (slot)
+ (if (and (slot-exists-using-class? old-class old-instance slot)
+ (eq? (slot-definition-allocation
+ (class-slot-definition old-class slot))
+ #:instance)
+ (slot-bound-using-class? old-class old-instance slot))
+ ;; Slot was present and allocated in old instance; copy it
+ (slot-set-using-class!
+ new-class
+ new-instance
+ slot
+ (slot-ref-using-class old-class old-instance slot))
+ ;; slot was absent; initialize it with its default value
+ (let ((init (slot-init-function new-class slot)))
+ (if init
+ (slot-set-using-class!
+ new-class
+ new-instance
+ slot
+ (apply init '()))))))
+ (map slot-definition-name (class-slots new-class)))
+ ;; Exchange old and new instance in place to keep pointers valid
+ (%modify-instance old-instance new-instance)
+ ;; Allow class specific updates of instances (which now are swapped)
+ (update-instance-for-different-class new-instance old-instance)
+ old-instance))
+
+
+(define-method (update-instance-for-different-class (old-instance <object>)
+ (new-instance
+ <object>))
+ ;;not really important what we do, we just need a default method
+ new-instance)
+
+(define-method (change-class (old-instance <object>) (new-class <class>))
+ (change-object-class old-instance (class-of old-instance) new-class))
+
+;;;
+;;; {make}
+;;;
+;;; A new definition which overwrites the previous one which was built-in
+;;;
+
+(define-method (allocate-instance (class <class>) initargs)
+ (%allocate-instance class initargs))
+
+(define-method (make-instance (class <class>) . initargs)
+ (let ((instance (allocate-instance class initargs)))
+ (initialize instance initargs)
+ instance))
+
+(define make make-instance)
+
+;;;
+;;; {apply-generic}
+;;;
+;;; Protocol for calling standard generic functions. This protocol is
+;;; not used for real <generic> functions (in this case we use a
+;;; completely C hard-coded protocol). Apply-generic is used by
+;;; goops for calls to subclasses of <generic> and <generic-with-setter>.
+;;; The code below is similar to the first MOP described in AMOP. In
+;;; particular, it doesn't used the currified approach to gf
+;;; call. There are 2 reasons for that:
+;;; - the protocol below is exposed to mimic completely the one written in C
+;;; - the currified protocol would be imho inefficient in C.
+;;;
+
+(define-method (apply-generic (gf <generic>) args)
+ (if (null? (slot-ref gf 'methods))
+ (no-method gf args))
+ (let ((methods (compute-applicable-methods gf args)))
+ (if methods
+ (apply-methods gf (sort-applicable-methods gf methods args) args)
+ (no-applicable-method gf args))))
+
+;; compute-applicable-methods is bound to %compute-applicable-methods.
+;; *fixme* use let
+(define %%compute-applicable-methods
+ (make <generic> #:name 'compute-applicable-methods))
+
+(define-method (%%compute-applicable-methods (gf <generic>) args)
+ (%compute-applicable-methods gf args))
+
+(set! compute-applicable-methods %%compute-applicable-methods)
+
+(define-method (sort-applicable-methods (gf <generic>) methods args)
+ (let ((targs (map class-of args)))
+ (sort methods (lambda (m1 m2) (method-more-specific? m1 m2 targs)))))
+
+(define-method (method-more-specific? (m1 <method>) (m2 <method>) targs)
+ (%method-more-specific? m1 m2 targs))
+
+(define-method (apply-method (gf <generic>) methods build-next args)
+ (apply (method-procedure (car methods))
+ (build-next (cdr methods) args)
+ args))
+
+(define-method (apply-methods (gf <generic>) (l <list>) args)
+ (letrec ((next (lambda (procs args)
+ (lambda new-args
+ (let ((a (if (null? new-args) args new-args)))
+ (if (null? procs)
+ (no-next-method gf a)
+ (apply-method gf procs next a)))))))
+ (apply-method gf l next args)))
+
+;; We don't want the following procedure to turn up in backtraces:
+(for-each (lambda (proc)
+ (set-procedure-property! proc 'system-procedure #t))
+ (list slot-unbound
+ slot-missing
+ no-next-method
+ no-applicable-method
+ no-method
+ ))
+
+;;;
+;;; {<composite-metaclass> and <active-metaclass>}
+;;;
+
+;(autoload "active-slot" <active-metaclass>)
+;(autoload "composite-slot" <composite-metaclass>)
+;(export <composite-metaclass> <active-metaclass>)
+
+;;;
+;;; {Tools}
+;;;
+
+;; list2set
+;;
+;; duplicate the standard list->set function but using eq instead of
+;; eqv which really sucks a lot, uselessly here
+;;
+(define (list2set l)
+ (let loop ((l l)
+ (res '()))
+ (cond
+ ((null? l) res)
+ ((memq (car l) res) (loop (cdr l) res))
+ (else (loop (cdr l) (cons (car l) res))))))
+
+(define (class-subclasses c)
+ (letrec ((allsubs (lambda (c)
+ (cons c (mapappend allsubs
+ (class-direct-subclasses c))))))
+ (list2set (cdr (allsubs c)))))
+
+(define (class-methods c)
+ (list2set (mapappend class-direct-methods
+ (cons c (class-subclasses c)))))
+
+;;;
+;;; {Final initialization}
+;;;
+
+;; Tell C code that the main bulk of Goops has been loaded
+(%goops-loaded)