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$f<TAB> x$ What do I miss ? I've uploaded foo here : addictedtor.free.fr/misc/rcpp/foo_1.0.tar.gz Romain -- Romain Francois Professional R Enthusiast +33(0) 6 28 91 30 30 romainfrancois.blog.free.fr |- bit.ly/9CQ66r : RMetrics 2010 |- bit.ly/cork4b : highlight 0.1-8 `- bit.ly/bklUXt : RcppArmadillo 0.2.1
This seems to do the trick, but it does not feel right: .onLoad <- function( libname, pkgname ){ utils <- asNamespace( "utils" ) unlockBinding( ".DollarNames", utils ) assignInNamespace( ".DollarNames", .DollarNames, utils ) lockBinding( ".DollarNames", utils ) } Any better idea ? Romain Le 29/05/10 13:21, Romain Francois a ?crit :> > 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$f<TAB> > x$ > > > What do I miss ? > > I've uploaded foo here : > addictedtor.free.fr/misc/rcpp/foo_1.0.tar.gz > > Romain > >-- Romain Francois Professional R Enthusiast +33(0) 6 28 91 30 30 romainfrancois.blog.free.fr |- bit.ly/9CQ66r : RMetrics 2010 |- bit.ly/cork4b : highlight 0.1-8 `- bit.ly/bklUXt : RcppArmadillo 0.2.1
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 : addictedtor.free.fr/misc/rcpp/foo_1.0.tar.gz > > Romain > > > -- > Romain Francois > Professional R Enthusiast > +33(0) 6 28 91 30 30 > romainfrancois.blog.free.fr > |- bit.ly/9CQ66r : RMetrics 2010 > |- bit.ly/cork4b : highlight 0.1-8 > `- bit.ly/bklUXt : RcppArmadillo 0.2.1 > > > ______________________________________________ > R-devel at r-project.org mailing list > stat.ethz.ch/mailman/listinfo/r-devel >
Thanks. I'll apply the nice workaround for now. Romain Le 29/05/10 23:15, John Chambers a ?crit :> The idea of modifying .DollarNames to recognize S4 methods is OK, but > the problem could arise again. > > It would be better to have a general solution. The general problem as > it seems is that an S3 generic called from within its package's > namespace (or from some other 3rd package) will not detect S4 methods. > In a sense, this is a natural consequence of namespace semantics and > therefore not a bug. We don't really want to fix up each case when it > arises. > > I can see two general solutions, one a reasonable fix that could likely > be implemented for 2.12.0, the other a slight hack added to make the > solution work now. > > Both solutions start with the idea that we continue to treat the S3 > generic as an S3 generic (at least when it's called from the owning > package's namespace). We then define an S3 method for the S4 class. > > Right now, that fails to recognize S4 inheritance (that's the fix that > should be doable for 2.12.0; most of the mechanism needed is already in > the UseMethod implementation). > > The workaround/hack that *does* work now, I believe, is to insert a > dummy S3 class into the mix and define the S3 .DollarNames method for it. > > Example: > > setOldClass("foo3") > > .DollarNames.foo3 <- function(x, pattern)"bar" > > > > setClass("foo", contains = "foo3", representation(x = "numeric")) > [1] "foo" > > > > ff = new("foo") > > > > setClass("fee", contains = "foo") > [1] "fee" > > > > fe = new("fee") > > Both ff$ and fe$ complete with "bar", running 2.11.0 from the command line. > > John > > > > > > On 5/29/10 12:37 PM, Romain Francois wrote: >> Le 29/05/10 20:23, Deepayan Sarkar a ?crit : >>> 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) >> >> yes. hence the hack I used when replying which is probably not a good >> idea, specially if two packages want it. >> >>> so the S4 generic is not being seen within the utils namespace. I >>> don't know what the right fix is... >>> >>> -Deepayan >> >> Perhaps something like the attached ? >> >> defining a generic in methods and use this one when methods dispatch >> is on. >> >> >>>> What do I miss ? >>>> >>>> I've uploaded foo here : >>>> addictedtor.free.fr/misc/rcpp/foo_1.0.tar.gz >>>> >>>> Romain >> >> >> ______________________________________________ >> R-devel at r-project.org mailing list >> stat.ethz.ch/mailman/listinfo/r-devel >>-- Romain Francois Professional R Enthusiast +33(0) 6 28 91 30 30 romainfrancois.blog.free.fr |- bit.ly/99bz5D : highlight 0.1-9 |- bit.ly/9CQ66r : RMetrics 2010 `- bit.ly/bklUXt : RcppArmadillo 0.2.1