[Rd] Problems with S4 methods dispatching on `...` (aka dotsMethods)

[Michael Lawrence]

I pushed the patch to the 3.4 branch. Feel free to test.

Michael

On Wed, Jul 26, 2017 at 4:02 AM, Andrzej Oleś <andrzej.oles at gmail.com> wrote:
> Hi Michael,
>
> it seems that your patch to S4 generics dispatching on `...` is still
> available only in R-devel, and was not included in the minor R-3.4.1
> release. I was wondering what is the policy of incorporating bug fixes from
> the devel branch into release, and whether there is any chance that the
> broken `...` dispatch is fixed before R-3.5.0?
>
> Cheers,
> Andrzej
>
>
> On Tue, Apr 25, 2017 at 4:15 PM, Andrzej Oleś <andrzej.oles at gmail.com>
> wrote:
>>
>> You're right, I must have mixed up my R versions when running the example,
>> as the problem seems to be resolved in R-devel.
>>
>> Sorry for the noise and thanks again for fixing this.
>>
>> Andrzej
>>
>> On Tue, Apr 25, 2017 at 3:55 PM, Michael Lawrence
>> <lawrence.michael at gene.com> wrote:
>>>
>>> I attempted to fix it, and that example seems to work for me. It's
>>> also a (passing) regression test in R. Are you sure you're using a new
>>> enough R-devel?
>>>
>>>
>>> On Tue, Apr 25, 2017 at 2:34 AM, Andrzej Oleś <andrzej.oles at gmail.com>
>>> wrote:
>>> > Hi Michael,
>>> >
>>> > thanks again for your patch! I've tested it and I'm happy to confirm
>>> > that
>>> > `callNextMethod()` works with methods dispatching on `...`.
>>> >
>>> > However, the second issue I reported still seems to be unresolved.
>>> > Consider
>>> > the following toy example, where the `f()` calls differ in result
>>> > depending
>>> > on whether the dispatch happens on a formal argument or the `...`
>>> > argument.
>>> >
>>> >
>>> >     f = function(x, ..., a = b) {
>>> >       b = "missing 'a'"
>>> >       print(a)
>>> >     }
>>> >
>>> >     f()
>>> >     ## [1] missing 'a'
>>> >
>>> >     f(a = 1)
>>> >     ## [1] 1
>>> >
>>> >     setGeneric("f", signature = "x")
>>> >
>>> >     # works as the non-generic version
>>> >     f()
>>> >     ## [1] missing 'a'
>>> >
>>> >     setGeneric("f", signature = "...")
>>> >
>>> >     # unexpectedly fails to find 'b'
>>> >     f()
>>> >     ## Error in print(a) : object 'b' not found
>>> >
>>> >
>>> > Any chances of fixing this?
>>> >
>>> > Cheers,
>>> > Andrzej
>>> >
>>> >
>>> >
>>> > On Fri, Apr 21, 2017 at 11:40 AM, Andrzej Oleś <andrzej.oles at gmail.com>
>>> > wrote:
>>> >>
>>> >> Great, thanks Michael for you quick response!
>>> >>
>>> >> I started off with a question on SO because I was not sure whether
>>> >> this
>>> >> was an actual bug or I was just missing something obvious. I'm looking
>>> >> forward to the patch.
>>> >>
>>> >> Cheers,
>>> >> Andrzej
>>> >>
>>> >>
>>> >> On Thu, Apr 20, 2017 at 10:28 PM, Michael Lawrence
>>> >> <lawrence.michael at gene.com> wrote:
>>> >>>
>>> >>> Thanks for pointing out these issues. I have a fix that I will commit
>>> >>> soon.
>>> >>>
>>> >>> Btw, I would never have seen the post on Stack Overflow. It's best to
>>> >>> report bugs on the bugzilla.
>>> >>>
>>> >>> Michael
>>> >>>
>>> >>> On Thu, Apr 20, 2017 at 8:30 AM, Andrzej Oleś
>>> >>> <andrzej.oles at gmail.com>
>>> >>> wrote:
>>> >>> > Hi all,
>>> >>> >
>>> >>> > I recently encountered some unexpected behavior with S4 generics
>>> >>> > dispatching on `...`, which I described in
>>> >>> >
>>> >>> >
>>> >>> > http://stackoverflow.com/questions/43499203/use-callnextmethod-with-dotsmethods
>>> >>> >
>>> >>> > TL;DR: `callNextMethod()` doesn't work in methods dispatching on
>>> >>> > `...`,
>>> >>> > and
>>> >>> > arguments of such methods are resolved differently than the
>>> >>> > arguments
>>> >>> > of
>>> >>> > methods dispatching on formal arguments.
>>> >>> >
>>> >>> > Could this indicate a potential problem with the implementation of
>>> >>> > the
>>> >>> > `...` dispatch?
>>> >>> >
>>> >>> > Cheers,
>>> >>> > Andrzej
>>> >>> >
>>> >>> >         [[alternative HTML version deleted]]
>>> >>> >
>>> >>> > ______________________________________________
>>> >>> > R-devel at r-project.org mailing list
>>> >>> > https://stat.ethz.ch/mailman/listinfo/r-devel
>>> >>
>>> >>
>>> >
>>
>>
>