The problem is a combination of a class union definition that includes a
basic type as a member, and is not in a package.
Class "numeric" is sealed, so at present setClassUnion() doesn't cache
the new superclass in the definition of "numeric". In 2.4.0 that
happens when a package is attached (before, it didn't happen at all).
It's _probably_ true that the caching should take place in
setClassUnion(), but that needs a little consideration.
Meanwhile the workaround is to call cacheMetaData(1) to cache the
information in the global environment--that's what happens when a
corresponding package is attached.
> setClassUnion("index", c("numeric", "character", "logical"))
[1] "index"
> cacheMetaData(1)
> extends("numeric")
[1] "numeric" "vector" "index"
Parlamis Franklin wrote:
> the code below has me confused:
>
> setClassUnion("index", c("numeric", "character", "logical"))
> extends("numeric") # i don't see the class union
> library(Matrix)
> extends("numeric") # now i see the class union
>
> i am aware that the "Matrix" package separately defines the "index"
> class union.
> is it the case that class definitions need to occur in packages?
>
> i am also having trouble dispatching on class unions defined in the
> global environment,
> which may just be the same problem.
Yes. You need to cacheMetaData(1) before calling foo(2).
> see code below:
>
> setClassUnion("numORchar", c("numeric", "character"))
> foo <- function(x) "Default"
> setMethod("foo", signature(x = "numORchar"),
> function(x) "numORchar")
> foo(2) # gives the default method
>
> franklin
>
> > version
> _
> platform powerpc-apple-darwin8.7.0
> arch powerpc
> os darwin8.7.0
> system powerpc, darwin8.7.0
> status
> major 2
> minor 4.0
> year 2006
> month 10
> day 03
> svn rev 39566
> language R
> version.string R version 2.4.0 (2006-10-03)
>
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> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>
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