Hello,
I have a question concerning "setClassUnion".
I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000.
I tried to use "setClassUnion" in a package I am currently working on.
The
situation is similar to the following example:
The DESCRIPTION file has entries:
Depends: R (>= 2.0.0), methods
Imports: methods
LazyLoad: yes
The NAMESPACE file has entries:
importClassesFrom("methods", "NULL", "numeric")
exportClass("OptionalNumeric", "class1",
"class2")
The example R code is:
.onLoad <- function(lib, pkg){
require("methods", character = TRUE, quietly = TRUE)
}
setClassUnion("OptionalNumeric", c("numeric",
"NULL"))
setClass("class1",
representation(test1 = "OptionalNumeric"),
prototype(test1 = numeric(1)))
# why does this not work?
# The error I get is:
# Error in makePrototypeFromClassDef(properties, ClassDef, immediate,
# where) :In making the prototype for class "class1" elements of the
# prototype failed to match the corresponding slot class: test1
# (class "OptionalNumeric ")
# Sourcing this into R gives no error for me
# but instead using
prototype(test1 = NULL)
# works
# Moreover, using the second version (with test1 = NULL)
# the following works, too
setClass("class2",
representation(test2 = "class1"),
prototype(test2 = new("class1", test1 = numeric(1))))
What am I doing wrong?
Can someone please explain this to me?
Thanks for your help,
Matthias
sorry, please replace exportClass by exportClasses> Hello, > > I have a question concerning "setClassUnion". > I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000. > > I tried to use "setClassUnion" in a package I am currently working on. > The situation is similar to the following example: > > The DESCRIPTION file has entries: > Depends: R (>= 2.0.0), methods > Imports: methods > LazyLoad: yes > > The NAMESPACE file has entries: > importClassesFrom("methods", "NULL", "numeric") > exportClass("OptionalNumeric", "class1", "class2")exportClasses("OptionalNumeric", "class1", "class2")> > The example R code is: > .onLoad <- function(lib, pkg){ > require("methods", character = TRUE, quietly = TRUE) > } > > setClassUnion("OptionalNumeric", c("numeric", "NULL")) > > setClass("class1", > representation(test1 = "OptionalNumeric"), > prototype(test1 = numeric(1))) > > # why does this not work? > # The error I get is: > # Error in makePrototypeFromClassDef(properties, ClassDef, immediate, # > where) :In making the prototype for class "class1" elements of the # > prototype failed to match the corresponding slot class: test1 > # (class "OptionalNumeric ") > # Sourcing this into R gives no error for me > > # but instead using > prototype(test1 = NULL) > # works > > # Moreover, using the second version (with test1 = NULL) > # the following works, too > setClass("class2", > representation(test2 = "class1"), > prototype(test2 = new("class1", test1 = numeric(1)))) > > What am I doing wrong? > Can someone please explain this to me? > > Thanks for your help, > Matthias > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html
Matthias.Kohl@uni-bayreuth.de wrote:> > Hello, > > I have a question concerning "setClassUnion".It's not really about setClassUnion, but a bug in handling slots in prototypes whose class extends a locally defined class (a class union is an example, but others would fail the same way).> I'm working with R 2.0.0 Patched (2004-10-06) on windows 2000. > > I tried to use "setClassUnion" in a package I am currently working on. The > situation is similar to the following example: > > The DESCRIPTION file has entries: > Depends: R (>= 2.0.0), methods > Imports: methods > LazyLoad: yes > > The NAMESPACE file has entries: > importClassesFrom("methods", "NULL", "numeric") > exportClass("OptionalNumeric", "class1", "class2") > > The example R code is: > .onLoad <- function(lib, pkg){ > require("methods", character = TRUE, quietly = TRUE) > } > > setClassUnion("OptionalNumeric", c("numeric", "NULL")) > > setClass("class1", > representation(test1 = "OptionalNumeric"), > prototype(test1 = numeric(1))) > > # why does this not work? > # The error I get is: > # Error in makePrototypeFromClassDef(properties, ClassDef, immediate, > # where) :In making the prototype for class "class1" elements of the > # prototype failed to match the corresponding slot class: test1 > # (class "OptionalNumeric ") > # Sourcing this into R gives no error for me > > # but instead using > prototype(test1 = NULL) > # works > > # Moreover, using the second version (with test1 = NULL) > # the following works, too > setClass("class2", > representation(test2 = "class1"), > prototype(test2 = new("class1", test1 = numeric(1)))) > > What am I doing wrong?Nothing in the example, although this mail was more appropriate for r-devel than r-help (see the posting guide), so I've rerouted the reply. The definition of OptionalNumeric is not generally visible during installation, and the code that is testing the prototype is not finding the definition when testing, in effect, is(numeric(1), "OptionalNumeric"). We fixed a number of similar problems for 2.0, but this seems to be one that got through. (NULL values are allowed in the prototype, at least for now, which is why changing test1 to NULL works; the test2 example works because the prototype has exactly the expected class, so no definition is needed). The fix is simple, though I may not get a chance to test & commit it for a couple of days.> Can someone please explain this to me? > > Thanks for your help, > Matthias > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html-- John M. Chambers jmc@bell-labs.com Bell Labs, Lucent Technologies office: (908)582-2681 700 Mountain Avenue, Room 2C-282 fax: (908)582-3340 Murray Hill, NJ 07974 web: http://www.cs.bell-labs.com/~jmc