Thanks, Luke.
That's more efficient for sure. I'd just have to rename about a zillion
existing internal methods -- but only once!
Additional advantage I see is ability to control WHICH methods I'd allow to be
overridden.
Russ
-----Original Message-----
From: Tierney, Luke <luke-tier...@uiowa.edu>
Sent: Saturday, August 10, 2019 3:15 PM
To: Lenth, Russell V <russell-le...@uiowa.edu>
Cc: Duncan Murdoch <murdoch.dun...@gmail.com>; Iñaki Ucar
<iu...@fedoraproject.org>; r-package-devel@r-project.org
Subject: Re: [R-pkg-devel] [External] Re: Farming out methods to other packages
You could have your default method handle the cases you can handle; if you want
that to dispatch you can use something like
recover_data.default <- function(object, ...)
default_recover_data(object, ...)
default_recover_data <- function(object, ...)
UseMethod("default_recover_data")
Best,
luke
On Sat, 10 Aug 2019, Lenth, Russell V wrote:
> Thanks, Duncan. That's helpful.
>
> In addition, I confess I had a closing parenthesis in the wrong place.
> Should be: . . . .GlobalEnv), silent = TRUE)
>
> Cheers,
>
> Russ
>
> -----Original Message-----
> From: Duncan Murdoch <murdoch.dun...@gmail.com>
> Sent: Saturday, August 10, 2019 2:43 PM
> To: Lenth, Russell V <russell-le...@uiowa.edu>; Iñaki Ucar
> <iu...@fedoraproject.org>
> Cc: r-package-devel@r-project.org
> Subject: Re: [R-pkg-devel] [External] Re: Farming out methods to other
> packages
>
> On 10/08/2019 3:27 p.m., Lenth, Russell V wrote:
>> Hmmmm, I thought of an approach -- a kind of manual dispatch
>> technique. My generic is
>>
>> recover_data <- function(object, ...) {
>> rd <- try(getS3method("recover_data", class(object)[1], envir =
>> .GlobalEnv, silent = TRUE))
>> if (!inherits(rd, "try-error"))
>> rd(object, ...)
>> else
>> UseMethod("recover_data")
>> }
>>
>> and similar for emm_basis. The idea is it tries to find the method among
>> globally registered ones, and if so, it uses it; otherwise, the internal one
>> is used.
>
> That's a bad test: class(object) might be a vector c("nomethod",
> "hasmethod"). You're only looking for recover_data.nomethod, and maybe only
> recover_data.hasmethod exists.
>
> The getS3method() function won't automatically iterate through the
> class, you'll need to do that yourself, for example
>
> S3methodOrDefault <- function(object, generic, default) {
> for (c in class(object)) {
> rd <- try(getS3method(generic, c, envir = .GlobalEnv, silent = TRUE))
> if (!inherits(rd, "try-error"))
> return(rd)
> }
> return(default)
> }
>
> used as
>
> S3methodOrDefault(object, "recover_data", internal_recover_data)
>
> Duncan Murdoch
>
> ______________________________________________
> R-package-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-package-devel
--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke-tier...@uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
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