From clausen at econ.upenn.edu  Tue May 22 13:51:54 2007
From: clausen at econ.upenn.edu (Andrew Clausen)
Date: Tue, 22 May 2007 07:51:54 -0400
Subject: [Rd] relist, an inverse operator to unlist
In-Reply-To: <m2r6p990j5.fsf@ziti.local>
References: <20070513172911.GP6923@econ.upenn.edu>
	<971536df0705131602p2e407fa2sd1d5e6984d2ffa56@mail.gmail.com>
	<20070514043240.GL28199@econ.upenn.edu>
	<971536df0705132354u6e2ae0cci9b1e42a766dc0ec5@mail.gmail.com>
	<17992.5499.383704.358418@stat.math.ethz.ch>
	<20070519153636.GJ21178@econ.upenn.edu>
	<20070519160413.GK21178@econ.upenn.edu> <m2r6p990j5.fsf@ziti.local>
Message-ID: <20070522115154.GS28199@econ.upenn.edu>

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



[Rd] relist, an inverse operator to unlist
Andrew Clausen