[Openmcl-devel] CLOS implementation weirdness?

Dirk E├čer essdir at web.de
Tue Jun 9 15:17:15 UTC 2015


The problem seems to be, that CCL defines a class LOCK already, which is 
accessible in package CL-USER (the current package right after starting 
the lisp). Due to this, you are not defining a new class, but trying to 
redefine the existing class (which fails).

To start with a clean package (i.e., only symbols, which the CLHS 
mandates), try

? (defpackage "FOO" (:use "COMMON-LISP"))
#<Package "FOO">
? (in-package "FOO")
#<Package "FOO">
? (defclass lock ()
   ((name :initarg :name :reader lock-name))
   (:documentation "The foundation of all locks."))
#<STANDARD-CLASS LOCK>

Cheers,
Dirk



Am 09.06.2015 um 17:10 schrieb Adam Jensen:
> Hi, I've recently started working through [Object-Oriented Programming in COMMON LISP: A Programmer's Guide to CLOS](http://www.amazon.com/Object-Oriented-Programming-COMMON-LISP-Programmers/dp/0201175894). The example code in chapter three yields some weird results.
>
> (defclass lock ()
>    ((name :initarg :name :reader lock-name))
>    (:documentation "The foundation of all locks."))
>
> CLISP and SBCL seem to be okay with this code snippet but CCL gives:
>
> Error: Class option :DOCUMENTATION is not one of (:NAME)
>
>
> Example:
> -----------------------------------------------------------------
> hanzer at helix:~$ clisp
>    i i i i i i i       ooooo    o        ooooooo   ooooo   ooooo
>    I I I I I I I      8     8   8           8     8     o  8    8
>    I  \ `+' /  I      8         8           8     8        8    8
>     \  `-+-'  /       8         8           8      ooooo   8oooo
>      `-__|__-'        8         8           8           8  8
>          |            8     o   8           8     o     8  8
>    ------+------       ooooo    8oooooo  ooo8ooo   ooooo   8
>
> Welcome to GNU CLISP 2.49 (2010-07-07) <http://clisp.cons.org/>
>
> Copyright (c) Bruno Haible, Michael Stoll 1992, 1993
> Copyright (c) Bruno Haible, Marcus Daniels 1994-1997
> Copyright (c) Bruno Haible, Pierpaolo Bernardi, Sam Steingold 1998
> Copyright (c) Bruno Haible, Sam Steingold 1999-2000
> Copyright (c) Sam Steingold, Bruno Haible 2001-2010
>
> Type :h and hit Enter for context help.
>
> [1]> (defclass lock ()
>    ((name :initarg :name :reader lock-name))
>    (:documentation "The foundation of all locks."))
> #<STANDARD-CLASS LOCK>
> [2]> (quit)
> Bye.
> hanzer at helix:~$ sbcl
> This is SBCL 1.2.11, an implementation of ANSI Common Lisp.
> More information about SBCL is available at <http://www.sbcl.org/>.
>
> SBCL is free software, provided as is, with absolutely no warranty.
> It is mostly in the public domain; some portions are provided under
> BSD-style licenses.  See the CREDITS and COPYING files in the
> distribution for more information.
> * (defclass lock ()
>    ((name :initarg :name :reader lock-name))
>    (:documentation "The foundation of all locks."))
>
> #<STANDARD-CLASS LOCK>
> * (quit)
> hanzer at helix:~$ ccl
> Welcome to Clozure Common Lisp Version 1.11-dev-r16390M-trunk  (LinuxX8632)!
>
> CCL is developed and maintained by Clozure Associates. For more information
> about CCL visit http://ccl.clozure.com.  To enquire about Clozure's Common Lisp
> consulting services e-mail info at clozure.com or visit http://www.clozure.com.
>
> ? (defclass lock ()
>    ((name :initarg :name :reader lock-name))
>    (:documentation "The foundation of all locks."))
>> Error: Class option :DOCUMENTATION is not one of (:NAME)
>> While executing: DEFCLASS, in process listener(1).
>> Type :POP to abort, :R for a list of available restarts.
>> Type :? for other options.
> 1 > (quit)
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