From: Timofei Shatrov
Subject: class named room...
Date: Sun, 07 Aug 2005 09:03:22 +0000
Message-ID: <42f5cada.11373640@news.readfreenews.net>

I want a class named room. But it (CLISP) just won't let me!

(defclass room () ())

(SETF FIND-CLASS)(ROOM): #1=#<PACKAGE COMMON-LISP> is locked
 [Condition of type SYSTEM::SIMPLE-PACKAGE-ERROR]

Does such a class already exist? I can find a function (room) but it
shouldn't prevent me from creating a class, right? Is there a way to
shadow the class but still have an access to the function?

-- 
|a\o/r|,-------------.,---------- Timofei Shatrov aka Grue ------------.
| m"a ||FC AMKAR PERM|| mail: grue at mail.ru  http://grue3.tripod.com |
|  k  ||  PWNZ J00   || Kingdom of Loathing: Grue3 lvl 18 Seal Clubber |
`-----'`-------------'`-------------------------------------------[4*72]

From: Christophe Rhodes
Subject: Re: class named room...
Date: Sun, 07 Aug 2005 10:05:53 +0000
Message-ID: <sq64ui83jy.fsf@cam.ac.uk>

····@mail.ru (Timofei Shatrov) writes:

> I want a class named room. But it (CLISP) just won't let me!
>
> (defclass room () ())
>
> (SETF FIND-CLASS)(ROOM): #1=#<PACKAGE COMMON-LISP> is locked
>  [Condition of type SYSTEM::SIMPLE-PACKAGE-ERROR]
>
> Does such a class already exist? I can find a function (room) but it
> shouldn't prevent me from creating a class, right? 

See CLHS 11.1.2.1.2.  (In one sentence, this restriction exists to
prevent your attempted definition of CL:ROOM as a class to collide
with some other user's definition of CL:ROOM.

> Is there a way to shadow the class but still have an access to the
> function?

(defpackage "MY-PACKAGE"
  (:use "CL")
  (:shadow "ROOM"))
(in-package "MY-PACKAGE")
(defun room (&optional (arg :default))
  (cl:room arg))
(define-compiler-macro room (&whole whole &optional arg)
  (declare (ignore arg))
  `(cl:room ,@(cdr whole)))

Christophe