[R] own TAB expansion

[Sebastian Gibb]

Am Samstag, 9. Oktober 2010, 08:39:36 schrieb Deepayan Sarkar:
> On Fri, Oct 8, 2010 at 6:19 AM, Sebastian Gibb <lists at sebastiangibb.de> 
wrote:
> > Hello Duncan,
> > 
> > thank for your advice, but it doesn't work like expected:
> > 
> > setClass(Class="A", representation=representation(slotA="numeric",
> > slotB="numeric"));
> > setMethod("$", "A", function(x, name) {return(slot(x, name));})
> > setGeneric(".DollarNames")
> > setMethod(".DollarNames", signature(x="A"), function(x,
> > pattern)grep(pattern=pattern, x=c("slotA", "slotB"), value=T))
> > 
> > a <- new("A", slotA=1, slotB=2)
> > a$sl  <TAB>
> > # doesn't print slotA/slotB
> > 
> >> a$
> > 
> > What I'm doing wrong?
> 
> There is a namespace issue with making .DollarNames() generic;
> basically, the completion code in the utils namespace never sees the
> new S4 generic. See a previous discussion at
> 
> http://www.mail-archive.com/r-devel@r-project.org/msg20553.html
> 
> Defining a S3 method should work (without the need for a dummy S3
> class even with inheritance if you are working with R 2.12):
> 
> .DollarNames.A <-
>     function(x, pattern) {
>         grep(pattern=pattern, x=c("slotA", "slotB"), value=T)
>     }
> 
> -Deepayan

Hello Deepayan,

thanks for the link. This solution works for R 2.12.

Bye

Sebastian