Thats not how I read the code? Consider this snippet from registerS3method:
genfun <- get(genname, envir = envir) if (.isMethodsDispatchOn() && methods::is(genfun, "genericFunction")) genfun <- methods::finalDefaultMethod(genfun@default) if (typeof(genfun) == "closure") environment(genfun) else .BaseNamespaceEnv This is the environment where the method cache (.__S3MethodsTable__.) will be updated. The problem hoverer, the with the default setting of _R_S3_METHOD_LOOKUP_USE_TOPENV_AS_DEFENV_ this is *not* the environment where R will look for the method cache. Manually injecting the entry into the method cache of the top environment instead works like a charm. The envir argument is just for looking up the generic function. Best, Taras > On 30 Jun 2021, at 13:29, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > > On 30/06/2021 7:23 a.m., Taras Zakharko wrote: >> I had another glance at the code and now I’m convinced that this is the bug >> in registerS3method(). Default R behavior (in objects.c) appears to be to >> look for method definitions in the top environment, not the defining >> environment, but registerS3method() registers the method in the defining >> environment. I think registerS3method() should be changed to something like: > > It registers wherever you ask it to. The default is the defining environment. > > .S3method is the one that always uses the defining environment, since it has > no way to override the default. > > Duncan Murdoch > >> - if (typeof(genfun) == "closure”) >> - environment(genfun) >> ------------ >> + if (typeof(genfun) == "closure”) >> + if(isFALSE(Sys.getenv("_R_S3_METHOD_LOOKUP_USE_TOPENV_AS_DEFENV_”)) >> environment(genfun) else topenv(environment(genfun)) >> in order to match the behavior of do_usemethod() >> Best, >> Taras >>> On 30 Jun 2021, at 12:51, Taras Zakharko <taras.zakha...@uzh.ch> wrote: >>> >>> @Duncan: .S3method() calls registerS3method() with appropriate >>> environmental argument under the good, so that’s not the problem. >>> >>> Anyway, I’ve been doing some debugging and I think I have found the issue. >>> The following snippet in src/objects.c >>> (https://github.com/wch/r-source/blob/ecc633b37d77fdd1cb27dda74d7f6b3684f0c01c/src/main/objects.c#L525) >>> sets the global lookup_use_topenv_as_defenv variable: >>> >>> >>> if(lookup_use_topenv_as_defenv == -1) { >>> lookup = getenv("_R_S3_METHOD_LOOKUP_USE_TOPENV_AS_DEFENV_"); >>> lookup_use_topenv_as_defenv = >>> ((lookup != NULL) && StringFalse(lookup)) ? 0 : 1; >>> } >>> >>> Isn’t that supposed to be >>> >>> lookup_use_topenv_as_defenv = ((lookup != NULL) && >>> StringFalse(lookup)) ? 1 : 0; >>> >>> instead? >>> >>> The way the code works right now, methods will be looked up in top >>> environment exactly if _R_S3_METHOD_LOOKUP_USE_TOPENV_AS_DEFENV_ is not >>> set. This seems incompatible with what registerS3method() does (setting the >>> .__S3MethodsTable__. on the defining environment instead of the topenv). >>> When I change 0 and 1 around, everything works as expected. >>> >>> In the meantime, I can work around it by manually injecting >>> __S3MethodsTable__ into .GlobalEnv (which is my topenv here). >>> >>> I can open a bug report, but I would like to wait for some more comments. >>> >>> Best, >>> >>> Taras >>> >>>> On 30 Jun 2021, at 12:39, Joshua Ulrich <josh.m.ulr...@gmail.com> wrote: >>>> >>>> On Wed, Jun 30, 2021 at 5:17 AM Duncan Murdoch <murdoch.dun...@gmail.com> >>>> wrote: >>>>> >>>>> On 30/06/2021 5:22 a.m., Taras Zakharko wrote: >>>>>> Dear all, >>>>>> >>>>>> I have a generic function and a bunch of methods defined in a separate >>>>>> environment. Here is a reduced example: >>>>>> >>>>>> env <- local({ >>>>>> # define the generic function and the method >>>>>> myfun <- function(x) UseMethod("myfun") >>>>>> myfun.myclass <- function(x) print("called myfun.myclass”) >>>>>> >>>>>> # register the method >>>>>> .S3method("myfun", "myclass", myfun.myclass) >>>>>> >>>>>> environment() >>>>>> }) >>>>>> >>>>>> Since the method has been registered, I hoped that invocation like this >>>>>> would work: >>>>>> >>>>>> env$myfun(structure(0, class = "myclass”)) >>>>>> >>>>>> However, this results in a “no applicable method" error. >>>>>> >>>>>> It is my understanding that registerS3method (called by .S3method) will >>>>>> install the method string in the .__S3MethodsTable__. table of the >>>>>> environment where the generic function is defined, and this table is >>>>>> subsequently used by usemethod() inside R, so I am puzzled that the >>>>>> dispatch does not work. I checked and the .__S3MethodsTable__. of env >>>>>> is indeed setup correctly. I also tried manually adding the method >>>>>> string to the global .__S3MethodsTable__. inside .BaseNamespaceEnv to no >>>>>> effect. >>>>>> >>>>>> In fact, the only way to make it work is to define either myfun or >>>>>> myfun.myclas in the global environment, which is something I would like >>>>>> to avoid. >>>>>> >>>>>> Thank you in advance for any pointers! >>>>>> >>>>> >>>>> registerS3method has an additional parameter "envir" which I believe >>>>> would end up set to env in your code. So this works: >>>>> >>>>>> eval(expression(myfun(structure(0, class = "myclass"))), envir = env) >>>>> [1] "called myfun.myclass" >>>>> >>>>> You could probably also call registerS3method with envir specified >>>>> appropriately and get your original expression to work. >>>>> >>>> That doesn't seem to work on 4.1.0 for me. The code below worked for >>>> me in Oct-2020, though I'm not sure what version of R I was using at >>>> the time. I was slow to upgrade to 4.0, so it was probably the latest >>>> 3.x version. >>>> >>>> env <- new.env() >>>> local({ >>>> # define the generic function and the method >>>> myfun <- function(x) { UseMethod("myfun", x) } >>>> >>>> # register the method >>>> registerS3method("myfun", "myclass", >>>> function(x) { print("called myfun.myclass") }, >>>> envir = env) >>>> }, envir = env) >>>> attach(env) >>>> myfun(structure(0, class = "myclass")) >>>> >>>> >>>>> Duncan Murdoch >>>>> >>>>> ______________________________________________ >>>>> R-devel@r-project.org mailing list >>>>> https://stat.ethz.ch/mailman/listinfo/r-devel >>>> >>>> >>>> >>>> -- >>>> Joshua Ulrich | about.me/joshuaulrich >>>> FOSS Trading | www.fosstrading.com >>> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel