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From: David Pirotte <david@altosw.be>
To: Andy Wingo <wingo@pobox.com>
Cc: guile-devel <guile-devel@gnu.org>
Subject: Re: goops - guile-clutter unexpected bug while using #:virtual slot allocation for a <clutter-actor> subclass
Date: Sat, 7 Feb 2015 14:08:12 -0200	[thread overview]
Message-ID: <20150207140812.00c94f72@capac> (raw)
In-Reply-To: <20150206220637.310db45e@capac>

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Hello Andy,

> > With the stable-2.0 or master branches, the current behavior is:
> > 
> >     scheme@(guile-user)> (use-modules (oop goops))
> >     scheme@(guile-user)> (define-class <a> ()
> >     ...   (foo #:getter foo #:init-keyword #:foo))
> >     scheme@(guile-user)> (define-class <b> (<a>))
> >     scheme@(guile-user)> (define obj (make <b> #:foo 34))
> >     scheme@(guile-user)> (define-method (foo (self <b>))
> >     ...   (pk "ahoy!")
> >     ...   (next-method))
> >     scheme@(guile-user)> (pk (foo obj))
> > 
> >     ;;; ("ahoy!")
> >     ERROR: In procedure scm-error:
> >     ERROR: No next method when calling #<<generic> foo (2)>
> >     with arguments (#<<b> 2c207e0>)
> > 
> >     Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
> >     scheme@(guile-user) [1]> 
> 
> Yes, expected, but to me, it is because of what I just said here below.
> 
> > > In this case indeed, the only method that exists and is applicable is
> > > the getter foo that <a> defines and<b> inherits: there is no
> > > next-method and calling (next-method) would be a user bug, in my
> > > opinion too.
> > 
> > So, we should be precise with terminology :)  In GOOPS, subclasses do
> > not inherit accessor methods.  (There was a bug in which they would; I
> > fixed that.)  Each subclass gets its own accessor method defined, if and
> > only if it has the corresponding slot, and that method is not inherited.

Some are, some are not...:

;;; module a.scm starts here
(define-module (a)
  #:use-module (oop goops)
  #:export (<a>
	    !v
	    !width
	    set-width))

(define-class <a> ()
  (v #:accessor !v
     #:init-keyword #:v
     #:allocation #:virtual
     #:slot-ref (lambda (self)
		  (pk "this is <a> v slot-ref, hello!"))
     #:slot-set! (lambda (self value)
		   (pk "this is <a> v slot-set!, hello!")))
  (width #:accessor !width #:init-keyword #:width #:init-value 0))

(define-method ((setter !width) (self <a>) width)
  (set-width self width))

(define-method (set-width (self <a>) width)
  ;; here comes complex code, computing earth orbit, captain's age...
  (pk "this is <a> !width setter method, hello!")
  (slot-set! self 'width width)
  width)
;;; module ends here

;;; module b.scm starts here
(define-module (b)
  #:use-module (oop goops)
  #:use-module (a)
  #:export (<b>)

  #:re-export (!v
	       !width
	       set-width))


(define-class <b> (<a>))
;;; module ends here

GNU Guile 2.0.11.114-649ec
Copyright (C) 1995-2014 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> 
scheme@(guile-user)> ,use (oop goops)
scheme@(guile-user)> ,use (b)
;;; note: source file ./b.scm
;;;       newer than compiled /home/david/.cache/guile/ccache/2.0-LE-8-2.0/usr/alto/projects/guile-tests/goops/setter-inheritance-bug/b.scm.go
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling ./b.scm
;;; note: source file ./a.scm
;;;       newer than compiled /home/david/.cache/guile/ccache/2.0-LE-8-2.0/usr/alto/projects/guile-tests/goops/setter-inheritance-bug/a.scm.go
;;; compiling ./a.scm
;;; compiled /home/david/.cache/guile/ccache/2.0-LE-8-2.0/usr/alto/projects/guile-tests/goops/setter-inheritance-bug/a.scm.go
;;; compiled /home/david/.cache/guile/ccache/2.0-LE-8-2.0/usr/alto/projects/guile-tests/goops/setter-inheritance-bug/b.scm.go
scheme@(guile-user)> (make <b>)
$2 = #<<b> 2334760>
scheme@(guile-user)> (!v $2)

;;; ("this is <a> v slot-ref, hello!")
$3 = "this is <a> v slot-ref, hello!"
scheme@(guile-user)> (set! (!v $2) 'blue)

;;; ("this is <a> v slot-set!, hello!")
$4 = "this is <a> v slot-set!, hello!"
scheme@(guile-user)> (set! (!width $2) 10)
$5 = 10
scheme@(guile-user)> 

Cheers,
David



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  parent reply	other threads:[~2015-02-07 16:08 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-19 19:46 goops - guile-clutter unexpected bug while using #:virtual slot allocation for a <clutter-actor> subclass David Pirotte
2014-12-19 23:42 ` Panicz Maciej Godek
2014-12-20  6:16   ` David Pirotte
2015-01-26 21:35 ` Andy Wingo
2015-01-27  1:00   ` David Pirotte
2015-01-27  8:29     ` Andy Wingo
2015-01-27 19:11       ` David Pirotte
2015-01-27 19:35         ` David Pirotte
2015-01-27 20:44         ` Andy Wingo
2015-01-28  3:05           ` David Pirotte
2015-01-28  3:36             ` David Pirotte
2015-01-28 12:57             ` Andy Wingo
2015-01-28 19:24               ` David Pirotte
2015-01-30 13:50           ` David Pirotte
2015-02-06 13:33             ` Andy Wingo
2015-02-06 17:09               ` David Pirotte
2015-02-06 17:49                 ` Andy Wingo
2015-02-07  0:06                   ` David Pirotte
2015-02-07 15:37                     ` Andy Wingo
2015-02-07 17:13                       ` David Pirotte
2015-02-07 16:08                     ` David Pirotte [this message]
2015-02-04 16:12           ` David Pirotte

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