Martin, Thanks! I'll use name for now.
Steve -----Original Message----- From: Martin Maechler [mailto:[EMAIL PROTECTED] Sent: Thursday, April 13, 2006 3:11 AM To: Steven Lacey Cc: [EMAIL PROTECTED]; r-help@stat.math.ethz.ch Subject: S4 class slot name 'names' is not allowed >>>>> "SteveL" == Steven Lacey <[EMAIL PROTECTED]> >>>>> on Wed, 12 Apr 2006 19:06:52 -0400 writes: SteveL> Hi, Why doesn't this work? setClass("tests", representation(names = "character")) tmp <- new("tests"); [EMAIL PROTECTED] <- "a" SteveL> Error in "slot<-"(object, name, TRUE, value) : SteveL> 'names' attribute [1] must be the same length as the vector [0] SteveL> Why does this work (replace names with name)? setClass("test", representation(name="character")) tmp <- new("test"); [EMAIL PROTECTED] <- "a" SteveL> I looked at the help for setClass, representation, SteveL> and slot and found no restriction on the slot names SteveL> other than that they "be any non-empty string, but SteveL> if the name is not made up of letters, numbers, and SteveL> '"."', it needs to be quoted". Hah, you got us! This *is* a bug - at least in the documentation ===> This goes to R-bugs as well. It's because of the current *implementation* of S4-classed objects in R [as an empty list with a list of unusual attributes] -- and because 'names' (and also, e.g., 'dimnames') are attributes in R with a very special treatment - in many places. I haven't delved into the internal code, but I know that this problem will go away ``as soon as'' the internal representation of S4-classed objects is replaced -- something that has been planned for a while and "just did not yet happen". Martin Maechler, ETH Zurich ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
