S4 dispatch for .DollarNames (utils)

On Sat, May 29, 2010 at 4:21 AM, Romain Francois
<romain at r-enthusiasts.com>  wrote:

Hello,

I'm trying to make .DollarNames generic and implement a method for it in a
package. .DollarNames is the function that is now called to get completion
possibilities.

My R code looks like this:

setGeneric( ".DollarNames" )

setClass("track",
         representation(x="numeric", y="numeric"))
## A class extending the previous, adding one more slot
setClass("trackCurve",
    representation(smooth = "numeric"),
    contains = "track")

setMethod( ".DollarNames", signature( x = "track", pattern = "character" ),
function(x, pattern){
        grep( pattern, c("foo", "bar"), value = TRUE )
} )


and the NAMESPACE :

import( utils )
exportMethods( .DollarNames )
exportClasses( track, trackCurve )


When I load the package, I can call .DollarNames explicitely :

require( foo )
x<- new( "trackCurve", x = 1:10, y = 1:10, smooth = 1:10 )
.DollarNames( x, "f" )

[1] "foo"

but completion does not work :

x$f<TAB>

x$

I guess because

utils:::.DollarNames(x, "f")

character(0)

so the S4 generic is not being seen within the utils namespace. I
don't know what the right fix is...

-Deepayan

What do I miss ?

I've uploaded foo here : http://addictedtor.free.fr/misc/rcpp/foo_1.0.tar.gz

Romain