>>>>> Martin Maechler
>>>>> on Fri, 15 Mar 2024 11:24:22 +0100 writes:
>>>>> Ivan Krylov
>>>>> on Thu, 14 Mar 2024 14:17:38 +0300 writes:
>> On Thu, 14 Mar 2024 10:41:54 +0100
>> Martin Maechler <maech...@stat.math.ethz.ch> wrote:
>>> Anybody trying S7 examples and see if they work w/o producing
>>> wrong warnings?
>> It looks like this is not applicable to S7. If I overwrite
>> as.data.frame with a newly created S7 generic, it fails to dispatch on
>> existing S3 classes:
>> new_generic('as.data.frame', 'x')(factor(1))
>> # Error: Can't find method for `as.data.frame(S3<factor>)`.
>> But there is no need to overwrite the generic, because S7 classes
>> should work with existing S3 generics:
>> foo <- new_class('foo', parent = class_double)
>> method(as.data.frame, foo) <- function(x) structure(
>> # this is probably not generally correct
>> list(x),
>> names = deparse1(substitute(x)),
>> row.names = seq_len(length(x)),
>> class = 'data.frame'
>> )
>> str(as.data.frame(foo(pi)))
>> # 'data.frame': 1 obs. of 1 variable:
>> # $ x: <foo> num 3.14
>> So I think that is nothing to break because S7 methods for
>> as.data.frame will rely on S3 for dispatch.
> Yes, as it should be. Thank you for checking..
>>> > The patch passes make check-devel, but I'm not sure how to safely
>>> > put setGeneric('as.data.frame'); as.data.frame(factor(1:10)) in a
>>> > regression test.
>>>
>>> {What's the danger/problem? we do have "similar" tests in both
>>> src/library/methods/tests/*.R
>>> tests/reg-S4.R
>>>
>>> -- maybe we can discuss bi-laterally (or here, as you prefer)
>>> }
>> This might be educational for other people wanting to add a regression
>> test to their patch. I see that tests/reg-tests-1e.R is already running
>> under options(warn = 2), so if I add the following near line 750
>> ("Deprecation of *direct* calls to as.data.frame.<someVector>")...
>> # Should not warn for a call from a derivedDefaultMethod to the raw
>> # S3 method -- implementation detail of S4 dispatch
>> setGeneric('as.data.frame')
>> as.data.frame(factor(1))
>> ...then as.data.frame will remain an S4 generic. Should the test then
>> rm(as.data.frame) and keep going? (Or even keep the S4 generic?) Is
>> there any hidden state I may be breaking for the rest of the test this
>> way?
>> The test does pass like this, so this may be worrying about nothing.
> Indeed, this could be educational; I think just adding
> removeGeneric('as.data.frame')
> is appropriate here as it is self-explaining and should not leave
> much traces.
> I'm about to test this in reg-tests-1e.R and with make check-all
> and commit later today,
> thanking you, Ivan!
This has been committed to R-devel svn rev 86139 now.
So these spurious warnings in situations where as.data.frame()
is an S4 generic --- notably for the many Bioconductor package
depending on {BiocGenerics} --- should disappear within 24
hours or less.
Martin
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