Subject: Re: bug#19770: goops - setter inheritance bug - serious
From: Andy Wingo <[email-masked]>
To: David Pirotte <[email-masked]>
Cc: [email-masked]
Date: Thu, 23 Jun 2016 11:11:21 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

Hi David,

Sorry for the long delay.  I think this is not a bug.  The reason is
that you defined !width as an #:accessor.  That means that each concrete
class which has a `width' slot will have its own accessor method
installed on it.  You overrode the method for <a> instances but not for
any other concrete class; e.g. <b> will have its own method.

If you want to run methods in the setter, you need to not define !width
as an accessor and instead rely on your define-method to create !width
as a normal generic.  I.e. remove #:accessor !width from (define-class
a).

Andy

On Wed 04 Feb 2015 16:43, David Pirotte <[email-masked]> writes:

> Hello,
>
> 	GNU Guile 2.0.11.114-649ec
> 	goops - setter inheritance bug
> 	severity - serious
>
> setters are beeing redefined, not inhereted:  this is a serious bug.
>
> Cheers,
> David
>
>
> (define-module (a)
>   #:use-module (oop goops)
>   #:export (<a>
> 	    !width))
>
>
> (define-class <a> ()
>   (width #:accessor !width #:init-keyword #:width #:init-value 0))
>
> (define-method ((setter !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))
>
> (define-module (b)
>   #:use-module (oop goops)
>   #:use-module (a)
>   #:export (<b>)
>
>   #:re-export (!width))
>
>
> (define-class <b> (<a>))
>
> 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)> (set! (!width (make <b>)) 20)
> $2 = 20
> scheme@(guile-user)> 
>