Thanks Duncan,
I finally found the reason for the mysterious dispatch-failure: I had an
unwanted and unexported replicated definition of the 'clone' generic in
ff's namespace (a left-over).
I still don't understand how this prevented the proper dispatch since
the duplicate in ff's namespace it was *not* called. I further
experimented and *any* non-exported object matching the name of the
generic caused the problem. Scary, maybe worth a check!
Anyhow, removing the non-exported object solved the problem.
Best regards
Jens
On 20.10.21 13:43, Jens Oehlschlägel wrote:
> Thank you Duncan,
>
> bit NAMESPACE has
>
> S3method(clone,default)
> export(clone)
>
> ff NAMESPACE has
>
> import(bit)
> # wish of CRAN maintainers: export another time here (now maintained
> and exported in bit)
> # without this R CMD CHECK complained, but with it R CMD CHECK
> complains also, how to export again and why?
> # clone
> #,clone.default
> clone.ff
> ,clone.ffdf
> S3method("clone",ff)
> S3method(clone, ffdf)
> # wish of CRAN maintainers: export another time here (now maintained
> and exported in bit)
> #S3method(clone, default)
>
> Best
>
> Jens
>
>
>
> On 20.10.21 11:02, Duncan Murdoch wrote:
>> On 19/10/2021 3:43 p.m., Jens Oehlschlägel wrote:
>>> I didn't find an answer elsewhere:
>>>
>>> My package 'bit' creates a S3 generic 'clone' and exports it.
>>> Furthermore it registers a S3 method 'clone.default' (not exported).
>>>
>>> My package 'ff' imports package 'bit' and exports and registers a
>>> new S3
>>> method 'clone.ff'. However, calling 'clone(ffobj)' dispatches to
>>> clone.default instead of clone.ff !? Why?
>>
>> You should show us the NAMESPACE entries involving clone and clone.ff
>> from ff.
>>
>> Some comments that may or may not be relevant:
>>
>> - Normally you wouldn't export clone.ff, it's enough to register it
>> using S3method().
>>
>> - You may have created a new generic named clone, and that's what
>> clone.ff would attach itself to. You can have bit::clone and
>> ff::clone as different generics and that would cause problems.
>>
>>>
>>> What is the recommended way to create new S3-methods that get
>>> dispatched? In earlier versions of the packages I simply exported
>>> everything - that worked.
>>
>> I import the generic and use S3method(generic, method). I don't
>> export the methods, so I wouldn't be able to call z <- clone.ff(a).
>>
>> Duncan Murdoch
>>
>>>
>>> Best
>>>
>>>
>>> Jens
>>>
>>>
>>> > require(ff)
>>> >
>>> > a <- as.ff(0:9)
>>> > class(x)
>>> [1] "ff_vector" "ff"
>>> >
>>> > x <- clone(a)
>>> > y <- bit:::clone.default(a)
>>> > z <- clone.ff(a)
>>> >
>>> > # cloned ffobjects should have different filenames>
>>>
>>> > filename(a) # original
>>> [1] "/tmp/Rtmpk17JRZ/ff/clone1ed54cbb5060.ff"
>>> >
>>> > filename(x) # unexpected equal (dispatch to clone.default)
>>> [1] "/tmp/Rtmpk17JRZ/ff/clone1ed54cbb5060.ff"
>>> >
>>> > filename(y) # expected equal
>>> [1] "/tmp/Rtmpk17JRZ/ff/clone1ed54cbb5060.ff"
>>> >
>>> > filename(z) # OK
>>> [1] "/tmp/Rtmpk17JRZ/ff/clone1ed551d3ee66.ff"
>>>
>>> > version
>>> _
>>> platform x86_64-pc-linux-gnu
>>> arch x86_64
>>> os linux-gnu
>>> system x86_64, linux-gnu
>>> status
>>> major 4
>>> minor 1.1
>>> year 2021
>>> month 08
>>> day 10
>>> svn rev 80725
>>> language R
>>> version.string R version 4.1.1 (2021-08-10)
>>> nickname Kick Things
>>>
>>> ______________________________________________
>>> R-package-devel using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
>>>
>>
>
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