Re: [Rd] S4 dispatch and S3 "connection" objects

From: Michael Lawrence <lawrence.michael_at_gene.com>
Date: Tue, 15 Dec 2009 06:34:43 -0800

On Mon, Dec 14, 2009 at 11:36 PM, Romain Francois < romain.francois_at_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
>
> --
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