[R] Re : ReferenceClasses examples {method}

[David Winsemius]

On Jan 28, 2011, at 12:35 PM, Marc Carpentier wrote:

> Right. Shame on me : Friday's tiredness ; I don't know why I stuck  
> on that.
> Please just consider the main topic of my message, regarding the  
> example of
> ReferenceClasses (supposing it's appropriate) and sorry for the  
> subsequent
> question...

I'm definitely the wrong one to tackle any S4 or ReferenceClasses  
questions. There have been some discussion on r-devel about how to  
pick up the ReferenceClasses methods but they flew right over my  
greying head. The latest incarnation of Baron's RSiteSearch allows  
searching the r-devel archives:

http://search.r-project.org/cgi-bin/namazu.cgi?query=ReferenceClasses&max=100&result=normal&sort=score&idxname=functions&idxname=Rhelp10&idxname=R-devel

And maybe other search strings could be even more productive, since I  
only tried one. I would have thought the ReferenceC;asses part of your  
question to be more appropriate for r-devel anyway.

-- 
David.



>
>
> ----- Message d'origine ----
>
> De : David Winsemius <dwinsemius at comcast.net>
> À : Marc Carpentier <marc.carpentier at ymail.com>
> Cc : r-help at r-project.org
> Envoyé le : Ven 28 janvier 2011, 17h 39min 59s
> Objet : Re: [R] ReferenceClasses examples {method}
>
>
> On Jan 28, 2011, at 11:05 AM, Marc Carpentier wrote:
>
>> Dear help, dear John Chambers,
>> I'm trying to learn OOP-possibilities in R and I was going through  
>> the
>> documentation 'ReferenceClasses {methods}'. (great work, by the  
>> way...)
>> Reading associated Examples, something bothers me : it seems to me  
>> that there
>> are errors in 'edit' and 'undo' methods. I think that :
>> - 'undo' should update 'edits' field with :
>> length(edits) <<- length(edits) - 1 #(and not - 2)
>> - and for coherence, 'edit' should store modifications in an  
>> 'append'-style :
>> edits <<- c(edits,list(backup)) #as opposed to c(list(backup),edits)
>>
>> I hope I'm not wrong.
>>
>> As a complementary question, suppose one kept  
>> 'c(edits,list(backup))', does
>> anyone know how todiscard first element(s) of a list? For a vector :
>> vedits<<-vedits[-1]
>> But lists can't be selected that way ( edits<<- edits [[-1]] #wrong )
>
> You are confusing "[" and "[["
>
>> ll <- list(a=1,b=2,cc=3)
>> ll[-1]
> $b
> [1] 2
>
> $cc
> [1] 3
>>
> --
> David Winsemius, MD
> West Hartford, CT
>
>
>

David Winsemius, MD
West Hartford, CT