Thanks, Bill. Searching R-devel based on your input shows that this is a known issue as pointed out by Martin Maechler:
https://stat.ethz.ch/pipermail/r-devel/2008-October/051109.html - Tom On Sun, Apr 12, 2009 at 11:34 PM, William Dunlap <wdun...@tibco.com> wrote: > > It may have to do with the results of is.object(): > > > is.object(1*structure(1,class="testClass")) > [1] FALSE > > is.object(structure(1,class="testClass")*1) > [1] TRUE > > is.object(structure(1,class="testClass")) > [1] TRUE > > is.object(x) should be true if x has a class attribute, > but 1*structute(1,class="testClass") makes a thing > with a class attribute but without the 'OBJECT' bit set. > > Bill Dunlap > TIBCO Software Inc - Spotfire Division > wdunlap tibco.com > > > -----Original Message----- > > From: r-devel-boun...@r-project.org > > [mailto:r-devel-boun...@r-project.org] On Behalf Of Tom Short > > Sent: Sunday, April 12, 2009 4:00 PM > > To: r-devel@r-project.org > > Subject: [Rd] Simple class with an automatic printing issue > > > > I don't understand the following behavior for a simple S3 class. The > > auto-printing at the command line > > doesn't behave as I expect. I'm probably missing something, > > but it might be > > a bug. > > > > > print.testClass <- function(x, ...) cat("Class:", class(x), > > ":", x, "\n") > > > > > structure(1, class = "testClass") > > Class: testClass : 1 > > > > > print(1 * structure(1, class = "testClass")) > > Class: testClass : 1 > > > > > 1 * structure(1, class = "testClass") # why doesn't > > auto-printing call > > print.testClass here? > > [1] 1 > > attr(,"class") > > [1] "testClass" > > > > > structure(1, class = "testClass") * 1 > > Class: testClass : 1 > > > > > > platform i386-pc-mingw32 > > arch i386 > > os mingw32 > > system i386, mingw32 > > status RC > > major 2 > > minor 9.0 > > year 2009 > > month 04 > > day 10 > > svn rev 48318 > > language R > > version.string R version 2.9.0 RC (2009-04-10 r48318) > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
