From ripley at stats.ox.ac.uk  Mon Apr 17 16:39:42 2006
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Mon, 17 Apr 2006 15:39:42 +0100 (BST)
Subject: [Rd] slot named C
In-Reply-To: <4443A656.4060306@bank-banque-canada.ca>
References: <444395BC.5020108@bank-banque-canada.ca>
	<Pine.LNX.4.64.0604171446130.3487@gannet.stats.ox.ac.uk>
	<4443A656.4060306@bank-banque-canada.ca>
Message-ID: <Pine.LNX.4.64.0604171536450.5712@gannet.stats.ox.ac.uk>

On Mon, 17 Apr 2006, Paul Gilbert wrote:

> Ok, but I'm surprised. I thought partial matching only happened for
> named arguments. I guess I've been lucky.

Here C is named, so what did you mean?

Partial matching happens for all arguments called by name, except for 
those following ... in the formals.

>
> Paul
>
> Prof Brian Ripley wrote:
>> It's an error in your usage  The args of new() are
>>
>>> args(new)
>> function (Class, ...)
>>
>> and what does 'C' match?  You need to name your arguments here.
>>
>> On Mon, 17 Apr 2006, Paul Gilbert wrote:
>>
>>> "C" appears to be an illegal name for a slot in an S4 class (example
>>> below).
>>
>> It is rather an example of something which does not work.
>>
>> foo <- new("testobj")
>> foo at C <- 2
>>
>> does, for example.
>>
>>> If this is a known limitation, and not a bug, it would be nice
>>> if it were caught by setClass.
>>>
>>> Paul Gilbert
>>>
>>>> setClass("testobj", representation ( C = "numeric"))
>>> [1] "testobj"
>>>> new("testobj", C= 2)
>>> Error in methodsPackageMetaName("C", name) :
>>>        'The name of the object (e.g,. a class or generic function) to
>>> find in the meta-data' must be a single string (got an object of class
>>> "numeric")
>>>
>>>> setClass("testobj", representation ( C. = "numeric"))
>>> [1] "testobj"
>>>> new("testobj", C.= 2)
>>> An object of class "testobj"
>>> Slot "C.":
>>> [1] 2
>>> ====================================================================================
>>>
>>>
>>> La version fran?aise suit le texte anglais.
>>>
>>> ------------------------------------------------------------------------------------
>>>
>>>
>>> This email may contain privileged and/or confidential
>>> inform...{{dropped}}
>>>
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>>
>>
> ====================================================================================
>
> La version fran?aise suit le texte anglais.
>
> ------------------------------------------------------------------------------------
>
> This email may contain privileged and/or confidential inform...{{dropped}}
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>

-- 
Brian D. Ripley,                  ripley at 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 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] slot named C
Prof Brian Ripley