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

Andrzej Oleś
2017-04-25T14:15:08Z

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 Ole? <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 Ole? <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 Ole? <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
> >>
> >>
> >