similar to: About the method dispatch mechanism

I have committed a change to R-devel that addresses this. To be on the safe side I need to run some more extensive tests before deciding if this can be ported to the release branch for R 3.5.0. Should know in a day or two. Best, luke On Tue, 27 Mar 2018, luke-tierney at uiowa.edu wrote: > This has nothing to do with printing or dispatch per se. It is the > result of an internal register

Hi, I initially opened an issue in the R6 repo because my issue was with an R6 object. But Winston (thanks!) further simplified my example, and it turns out that the issue (whether a feature or a bug is yet to be seen) had to do with S3 dispatching. The following example, by Winston, depicts the issue: print.foo <- function(x, ...) { cat("print.foo called\n") invisible(x) }

Hello, I've been attempting to make a generic method that dispatches on the first argument, which can be either an S3 or an S4 class. This is as far as I've gotten. Any suggestions about what to try next ? library(aroma.affymetrix) library(GenomicRanges) setGeneric("analyse", function(x, y, ...) standardGeneric("analyse")) setMethodS3("analyse",

(opening new bug report thread, on suggestion of BDR ..) I said on vaguely related topic: MM> There's another long-standing MM> UseMethod / NextMethod / Dispatch problem that I've never traced/solved.. MM> MM> Look at the $RHOME/tests/mode-methods.R file ! Peter Dalgaard already remarked : PD> ..i.e. this: PD> abc <- function(x, ...) { PD> if

Dear all, I have define a function and its methods as follows: ######## beginning of code fn <- function(x,...){ UseMethod("fn") } fn.foo1 <- function(x, commonA=1, ...){ print("fn.foo1 is called.") } fn.foo2 <- function(x, uniqueFoo2, common=1, ...){ ## uniqueFoo2 is a unique argument in fn.foo2 x <- uniqueFoo2; class(x) <- "foo1" ## use uniqueFoo2

2018-03-27 6:02 GMT+02:00 <luke-tierney at uiowa.edu>: > This has nothing to do with printing or dispatch per se. It is the > result of an internal register (R_ReturnedValue) being protected. It > gets rewritten whenever there is a jump, e.g. by an explicit return > call. So a simplified example is > > new_foo <- function() { > e <- new.env() >

I created a type of object similar to a data frame. In some circumstances, It needs special methods for "[" and "[<-" and rbind() (but not cbind()). Then I found this in the cbind()/rbind() man page: The method dispatching is _not_ done via 'UseMethod()', but by C-internal dispatching. Therefore, there is no need for, e.g., 'rbind.default'.

This has nothing to do with printing or dispatch per se. It is the result of an internal register (R_ReturnedValue) being protected. It gets rewritten whenever there is a jump, e.g. by an explicit return call. So a simplified example is new_foo <- function() { e <- new.env() reg.finalizer(e, function(e) message("Finalizer called")) e } bar <- function(x)

CCing r-devel. On Tue, 14 May 2019 at 02:11, Pavel Krivitsky <pavel at uow.edu.au> wrote: > > Dear All, > > I've run into this while updating a package with unfortunately named > legacy functions. It seems like something that might be worth changing > in R, and I want to get a sense of whether this is a problem before > submitting a report to the Bugzilla. > >

See also .isMethodsDispatchOn, which is what trace uses to decide if the methods package needs to be loaded. ~G On Tue, Apr 19, 2016 at 5:34 AM, Michael Lawrence <lawrence.michael at gene.com > wrote: > Not sure why R_has_methods_attached() exists. Maybe Martin could shed > some light on that. > > On Mon, Apr 18, 2016 at 11:50 PM, Kirill M?ller > <kirill.mueller at

Scenario: An S3 method is declared for an S4 base class but called for an instance of a derived class. Steps to reproduce: > Rscript -e "test <- function(x) UseMethod('test', x); test.Matrix <- function(x) 'Hi'; MatrixDispatchTest::test(Matrix::Matrix())" Error in UseMethod("test", x) : no applicable method for 'test' applied to an

Does it make sense to be able to load an S4 object without the methods package being attached? I'm not sure implementation-wise how easy this would be, but it seems like any time there is an S4 object around, the methods package should be available to deal with it. ~G On Tue, Apr 19, 2016 at 7:34 AM, Michael Lawrence <lawrence.michael at gene.com > wrote: > Right,

2018-03-27 11:11 GMT+02:00 Tomas Kalibera <tomas.kalibera at gmail.com>: > On 03/27/2018 09:51 AM, I?aki ?car wrote: >> >> 2018-03-27 6:02 GMT+02:00 <luke-tierney at uiowa.edu>: >>> >>> This has nothing to do with printing or dispatch per se. It is the >>> result of an internal register (R_ReturnedValue) being protected. It >>> gets

I do not understand what your goal is here (more context may be helpful, perhaps to others rather than me). So I doubt this is what you want, but here is a guess -- no need to respond if it is unhelpful: ## test.default returns NULL if object "y" not found in **calling environment and enclosures**; ## otherwise y. test <- function(x){ UseMethod("test") } test.default

Thanks for looking into it, your approach sounds good to me. See also R_has_methods_attached() (https://github.com/wch/r-source/blob/42ecf5f492a005f5398cbb4c9becd4aa5af9d05c/src/main/objects.c#L258-L265). I'm fine with Rscript not loading "methods", as long as everything works properly with "methods" loaded but not attached. -Kirill On 19.04.2016 04:10, Michael

I'd like to suggest that whenever there is no S3 method implementation available for a particular class, that the error message would also report the class structure of the object dispatched on. Example: foo <- function(...) UseMethod("foo") foo.ClassA <- function(object, ...) { cat("foo() for ClassA called.\n") } > foo(structure(1, class="ClassA"))

Hi, although I've done S3 dispatching for more than a decade now, I think I managed to overlook/avoid the following pitfall when using NextMethod(): If you explicitly pass argument '...' to NextMethod(), you will effectively pass those argument twice to the "next" method! EXAMPLE: foo0 <- function(...) UseMethod("foo0"); foo1 <- function(...)

Dear Martin, What's the ETA for _R_CLASS_MATRIX_ARRAY_=TRUE to become the new unconditional behavior in R devel? Thanks! H. On 11/21/19 08:57, Martin Maechler wrote: > > TLDR: This is quite technical, still somewhat important: > 1) R 4.0.0 will become a bit more coherent: a matrix is an array > 2) Your package (or one you use) may be affected. > >

Dear All, In R 3.6.3 (and earlier), method dispatch used to work for methods stored in local environments that are attached to the search path. For example: myfun <- function(y) { out <- list(y=y) class(out) <- "myclass" return(out) } print.myclass <- function(x, ...) print(formatC(x$y, format="f", digits=5)) myfun(1:4) # prints: [1]

Hi, Could someone point me in the right direction for documentation on the following question? Let's say I have two objects a and b of classes A and B, respectively. Now let's say I write a function foo that does something similar to objects of type A and B. Basically I want to overload the function in C++ talk, so if I give foo and object of type A something (and this is my question)