I recently moved a function 'subset.with.warning' into the 'mvbutils' package
(a version not yet on CRAN). When I tried RCMD CHECK, I got this warning:
* checking S3 generic/method consistency ... WARNING
subset:
function(x, ...)
subset.with.warning:
function(x, cond, mess.head, mess.cond, row.info, sub)
See section 'Generic functions and methods' of the 'Writing R
Extensions'
manual.
I know that S3 method arguments need to be compatible with arguments of the
generic. However, 'subset.with.warning' is deliberately not a registered S3
method, and its USAGE section doesn't include a \method{generic}{class}
statement. I couldn't see anything in "R Extensions" that says "don't do this",
so I'm wondering:
- should this really be a NOTE not a WARNING (or nothing at all)?
- if not, shouldn't there be a more explicit statement to the effect that "if
R decides it's a method, then it damned well is a method, whether you think it
is or not"?
- and if so, should there also be a check for functions that look like methods
but aren't registered and declared as such?
My preference would be for the first, FWIW. Admittedly, just because I didn't
register 'subset.with.warning' as an S3 method, that won't stop 'subset' from
trying to use it if it ever encounters an object of class "with.warning". It's
a risk that I'm happy to take, though CRAN might not be...
I made the warning go away by adding a '...' argument to the end of
'subset.with.warning', but that's not pretty.
Mark Bravington
CSIRO
Hobart
Australia
> sessionInfo()
R version 2.11.1 Patched (2010-06-30 r52418)
i386-pc-mingw32
locale:
[1] LC_COLLATE=English_Australia.1252 LC_CTYPE=English_Australia.1252
LC_MONETARY=English_Australia.1252 LC_NUMERIC=C
[5] LC_TIME=English_Australia.1252
attached base packages:
[1] grDevices tools tcltk stats graphics utils methods base
other attached packages:
[1] ad_1.0 chstuff_1.0 handy2_1.2 tweedie_2.0.2 statmod_1.4.1
handy_1.1 debug_1.2.3 mvbutils_2.5.2
>
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
