[Rd] relist, an inverse operator to unlist

Andrew Clausen clausen at econ.upenn.edu
Tue May 22 13:51:54 CEST 2007


Hi Seth,

On Mon, May 21, 2007 at 05:15:10PM -0700, Seth Falcon wrote:
> I will also add that the notion of a default argument on a generic
> function seems a bit odd to me.  If an argument is available for
> dispatch, I just don't see what sense it makes to have a default.  In
> those cases, the default should be handled by the method that has a
> signature with said argument matching the "missing" class.
> 
> What often does make sense is to define a generic function where some
> argument are not available for dispatch.  For example:
> 
> setGeneric("foo", signature="flesh",
>            function(flesh, skeleton=attr(flesh, "skeleton") 
>                standardGeneric("foo")))

That's an excellent suggestion.  Thanks!  However, I had to set the signature
to c("numeric", "missing") rather than just "numeric".

I have uploaded a new version here:

	http://www.econ.upenn.edu/~clausen/computing/relist.R

Cheers,
Andrew



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