From ripley at stats.ox.ac.uk  Mon Mar 31 13:39:41 2003
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Mon Mar 31 13:39:57 2003
Subject: [Rd] setIs?
In-Reply-To: <Pine.SOL.4.30.0303310454410.27421-100000@ysidro.econ.uiuc.edu>
Message-ID: <Pine.GSO.4.31.0303311235380.15925-100000@toucan.stats>

That's not the current version you are using, and it does work in the
current version.

However, that was caused by an additional consistency check, so I believe
it revealed a bug in the older version that we have not yet tracked down
(but have turned the check off).


On Mon, 31 Mar 2003, Roger Koenker wrote:

> I've recently updated from an early February version of 1.7.0 to
>
> Version 1.7.0 Under development (unstable) (2003-03-25)
>
> and am now having problems with errors giving the message:
>
>   ' getExtends(ClassDef) : @ must be used on an object with a formal class'
>
> which seems to be caused by 'setIs("character","character or NULL")'
> which attempts to define 'character' as an extension of the virtual
> class 'character or NULL' defined in 'setClass("character or NULL")'.
> If I try this:
>
> > library(methods)
> > setClass("CN")
> [1] "CN"
> > setIs("NULL","CN")
> > setIs("numeric","CN")
> > setIs("character","CN")
> Error in getExtends(ClassDef) : @ must be used on an object with a formal class
>
> The fact that 'setIs("numeric","CN")' and 'setIs("NULL","CN")' work just fine
> leads me to believe that this is a bug in the new R-devel version.

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] setIs?
Prof Brian Ripley