We should probably incorporate this information in the pre-defined S4 
versions of the classes, since these are basic S3 classes. Anybody see a 
down side?

Meanwhile, your approach is a reasonable workaround.

John

Michael Lawrence wrote:
> On Mon, Dec 14, 2009 at 11:36 PM, Romain Francois <
> romain.franc...@dbmail.com> wrote:
>
>   
>> Hello,
>>
>> I'm trying to get S4 dispatch on S3 "connection" objects.
>>
>> So I do :
>>
>> setOldClass( "connection" )
>>
>> and then :
>>
>> setGeneric( "bling", function(object) standardGeneric( "bling" ) )
>> setMethod( "bling", "connection", function(object) cat( "gotcha ",
>> as.integer(object), "\n" ) )
>>
>> but I get :
>>
>> f <- file( "blabla", open = "rb" )
>>
>>     
>>> bling( f )
>>>       
>> Error in function (classes, fdef, mtable)  :
>>  unable to find an inherited method for function "bling", for signature
>> "file"
>>     
>>> class( f )
>>>       
>> [1] "file"       "connection"
>>
>>
>> Am I supposed to do :
>>
>> setOldClass( c("file", "connection" ) )
>> setOldClass( c("url", "connection" ) )
>>
>> and so on for each potential S3 class, or is there another way.
>>
>>
>>     
> That's the way I've always done it.
>
> Michael
>
>
>   
>> Romain
>>
>> --
>> Romain Francois
>> Professional R Enthusiast
>> +33(0) 6 28 91 30 30
>> http://romainfrancois.blog.free.fr
>> |- http://tr.im/HlX9 : new package : bibtex
>> |- http://tr.im/Gq7i : ohloh
>> `- http://tr.im/FtUu : new package : highlight
>>
>> ______________________________________________
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>>
>>     
>
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