[Rd] Possible Regression in setClassUnion between 3.5.0 and 3.6.0

[Michael Lawrence]

Thanks, I'll look into it.

On Tue, Feb 18, 2020 at 8:32 AM Ezra Tucker <ezztucker using gmail.com> wrote:
>
> Hi Robert,
>
> This looks like a bug to me (tested in R 3.6.2 on Windows), f(new("a"))
> should return "hi!". I'll add that this DOES work properly in 3.6.1
> which leads me to suspect this could be due to the subtle change in the
> way method dispatch was performed to fix a different bug, in 3.6.2. Can
> anybody else confirm that?
>
>
> On 2/18/2020 9:32 AM, Robert Harlow wrote:
> > I am trying to create a class union of class unions to facilitate method
> > dispatch. When I execute code in the global environment, everything acts as
> > expected, however when I put the same code in the context of a package,
> > selectMethod can no longer find the correct method. This first block below
> > puts the code in the context of a package:
> >
> > fn <- "codefile.R"
> > writeLines(
> >      c(
> >          "setClass('x', slots = list(slot ='character'))",
> >          "setClass('y', slots = list(slot ='character'))",
> >          "setClass('a', slots = list(slot ='character'))",
> >          "setClass('b', slots = list(slot ='character'))",
> >          "setClassUnion('xy', c('x', 'y'))",
> >          "setClassUnion('ab', c('a', 'b'))",
> >          "setClassUnion('xyab', c('xy', 'ab'))",
> >          "setGeneric('f', function(object, ...) standardGeneric('f'))",
> >          "setMethod('f', 'xyab', function(object, ...) print('hi!'))"
> >      ),
> >      con = fn
> > )
> > package.skeleton(code_files = "codefile.R")
> > system("rm -rf anRpackage/man")
> > system("R CMD INSTALL anRpackage")
> > library(anRpackage)
> > ## fails in R 3.6.2, but works in R 3.5.0
> > f(new("a"))
> >
> > Next, if a fresh R 3.6.2 session is started and I execute the following at
> > the prompt, method dispatch works as expected.
> >
> > setClass("x", slots = list(slot ="character"))
> > setClass("y", slots = list(slot ="character"))
> > setClass("a", slots = list(slot ="character"))
> > setClass("b", slots = list(slot ="character"))
> > setClassUnion("xy", c("x", "y"))
> > setClassUnion("ab", c("a", "b"))
> > setClassUnion("xyab", c("xy", "ab"))
> > setGeneric("f", function(object, ...) standardGeneric("f"))
> > setMethod("f", "xyab", function(object, ...) print("hi!"))
> > ## print's "hi!" as expected
> > f(new("a"))
> >
> > I have also posted to stack overflow here:
> > https://stackoverflow.com/questions/60264786/r-s4-class-union-of-class-unions?noredirect=1#comment106627883_60264786,
> > (the example in this note removes devtools to make the environment
> > cleaner).
> >
> > Interestingly, the issue only seems to arise when there are > 1 layer
> > of the class union. E.g. if I were to setMethod on "ab" instead of
> > "xyab", method dispatch would work as expected. I am not posting a bug
> > yet as it is still unclear to me if I am doing something incorrect.
> >
> > My sessionInfo() is :
> >
> > R version 3.6.2 (2019-12-12)
> > Platform: x86_64-pc-linux-gnu (64-bit)
> > Running under: Ubuntu 18.04.3 LTS
> >
> > Matrix products: default
> > BLAS:   /usr/local/lib/R/lib/libRblas.so
> > LAPACK: /usr/local/lib/R/lib/libRlapack.so
> >
> > locale:
> >   [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> >   [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
> >   [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
> >   [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
> >   [9] LC_ADDRESS=C               LC_TELEPHONE=C
> > [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
> >
> > attached base packages:
> > [1] stats     graphics  grDevices utils     datasets  methods   base
> >
> > other attached packages:
> > [1] anRpackage_1.0
> >
> > loaded via a namespace (and not attached):
> > [1] compiler_3.6.2 tools_3.6.2
> >
> > Thanks in advance for the help!
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
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> > https://stat.ethz.ch/mailman/listinfo/r-devel
>
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-- 
Michael Lawrence
Senior Scientist, Bioinformatics and Computational Biology
Genentech, A Member of the Roche Group
Office +1 (650) 225-7760
michafla using gene.com

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