Message-ID: <5db91d48-6687-cd4f-558e-a5853c3efdea@truecluster.com>
Date: 2021-10-20T11:43:13Z
From: Jens Oehlschlägel
Subject: [R-pkg-devel] failing S3 dispatch
In-Reply-To: <2413a4ad-1cc9-9e89-30d2-51dd9272b727@gmail.com>
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 Oehlschl?gel 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 at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
>>
>