similar to: Possible bug in 'new()' for Reference Classes

Dear list, a while ago I posted this at r-devel but got no answers. Hope it?s okay to give it a shot again by cross-posting it here. TIA for any comments, Janko Von: Janko Thyson [mailto:janko.thyson.rstuff at googlemail.com] Gesendet: Montag, 21. Februar 2011 00:58 An: r-devel at r-project. org (r-devel at r-project.org) Betreff: Reference classes: error with missing arguments in method calls

Dear list, I have a reference class which should act as a "generic" superclass for other classes. I've read the respective section at ?setRefClass and put the name of the superclass to the 'contains' argument of an example subclass (see class defs below). Classnames are set in a way that shouldn't result in collation issues (virtual def sourced before superclass def

Dear list, I was wondering if you could help me out in clarifying something: Is it possible to use class "ANY" in slots/fields of formal classes if you a) do not want to restrict valid classes of that field and b) if you are making explicit use of class inheritance? It seems to work in simple scenarios but produces errors when class inheritance comes into play. So I was

Dear list, just to make sure that I understand 'unregistering' methods for S4 reference classes correctly: If I registered a method and want to 'unregister' (i.e. remove) this method again, objects/instance created of the respective class still feature the removed method until I do an explicit reassign ('my.instance <- getRefClass("Classname")$new()'), right?

Dear list, I came across a behavior that IMHO is somewhat undesired when calling '$field()': If the field name whose value you're trying to get is *not* a valid field of the Reference Class, then R doesn't stop there with an error, but scans through all enclosing environments/frames. The result is something similar to calling '|get(<objname>, inherits=TRUE)|'

Hi there, I''d like to choose between an "static" and "dynamic" access of a reference class field, say ''a''. myObj <- getRefClass("Blabla")$new() Static: myObj$a Dynamic: myObj$a.get() where the function retrieves the data from a database (or some other location), stores it to a buffer and

Dear list, is there a shortcut-function to check whether a class is a Reference Class or not? There's something like this for S4 classes ('isS4(object)'), but I couldn't find anything regarding Ref Classes. Currently, I'm doing it this way, which is a bit clumsy: A <- setRefClass("A", fields=list(X="numeric")) a <- A$new() isRefClass <-

Sorry guys, but I chose a really stupid name before (no "reference classes"). Hope it's okay to re-post. Cheers, Janko >>> ORIGINAL MESSAGE <<< Dear list, Is it possible to update or reassign '.self' with an image of '.self' (e.g. a locally stored .Rda file) from within a method? I know that this might sound akward, but here's the use

Dear list, I don't know what's the correct term for this in the OOP context, but is it possible to "clone"/copy an instance of a reference class (say 'a') so that I get an *autonomous* second instance 'b'? Autonomous in the sense that changes to 'a' do not affect 'b'. I know that this is somewhat against the pass-by-reference paradigm, but the

Dear list, is it possible that method dispatch checks for superclasses/virtual classes before checking "ANY"? I'd like to build a generic initialization method for all my Reference Class (say "MyDataFrame") objects by having them inherit from class, say "MyRefClassVirtual" (which would have to be a virtual S4 class; there are no virtual Reference Classes,

Dear list, I make use of cached objects extensively for time consuming computations and yesterday I happened to notice some very strange behavior in that respect: When I execute a given computation whose result I'd like to cache (tried both saving it as '.Rdata' and via package 'R.cache' which uses a own filetype '.Rcache'), my R session consumes about 200 MB of

Dear list, I'm wondering if the following error I'm getting is a small bug in the Reference Class paradigm or if it makes perfect sense. When you write an explicit initialize method for a Ref Class, can you then make use of '.self' WITHIN this initialize method just as you would once an object of the class has actually been initialized? Because it seems to me that you can not.

Dear list, I wonder how to write methods for the function 'as' in the sense that I can call 'as(object, Class, strict=TRUE, ext)' and let method dispatch figure out the correct method. AFAIU, there is a difference between, e.g. 'as.data.frame' and the methods of 'as()' as stated above since the former depends on arg 'x' instead of 'object',

Dear list, is there a way to declare public and private methods in S4 Reference Classes? If not, are there plans to add such a feature? You'll find a small code example of what I mean at Stackoverflow: http://stackoverflow.com/questions/11073253/oop-with-r-is-there-a-way-to-declare-public-and-private-methods-s4-reference-c Thanks a lot, Janko Thyson

Dear List, I am not really familiar with any other language than R, but I?ve heard that in other languages there is something called ?self referencing?. Here?s what I?m trying to get an answer for: Suppose there is a function that takes as its input a value of a slot of an S4 object. The function itself is stored in another slot of the SAME S4 object. Is it then possible to have the function

Dear List, I'm trying to figure out some best practice way with respect to the naming conventions when building own packages. I'd like to minimize the risk of choosing function names that might interfere with those of other packages (both available ones and those yet to come). I came up with following alternatives 1. Prefixing the actual names (e.g. myPkgfoo() instead of foo()): pretty

Dear list, today I stumbled across the function ?nsl()? for the first time in order to perform a hostname lookup. According to the R Reference Index (Version 2.9.1, page 1522), the function should be part of the "utils" package. However, I cannot find it in the utils package of my installation(s). I've tried the R-versions 2.8.1, 2.9.0 and 2.9.1. I'd be very thankful if

Dear List, I’m doing my first baby steps towards developing own R Packages and ran into the following problem: R CMD check mypackage works fine (no errors, no warnings) R CMD build mypackage works fine (no errors, no warnings) R CMD INSTALL –library=”C:\R\R-2.11.1\library” “something\mypackage\mypackage_1.0.tar.gz” works fine (no errors, no warnings) However, when I try loading the

Dear List, I’m doing my first baby steps towards developing own R Packages and ran into the following problem: R CMD check mypackage works fine (no errors, no warnings) R CMD build mypackage works fine (no errors, no warnings) R CMD INSTALL –library=”C:\R\R-2.11.1\library” “something\mypackage\mypackage_1.0.tar.gz” works fine (no errors, no warnings) However, when I try loading the

Dear list, I'm a bit puzzled by an ambiguity with respect to the representation of micro-/milliseconds when using 'POSIXlt' objects. It seems that the last digit of the 'sec' attribute sometimes seems to differ from the digits shown when printing the 'POSIXlt' object. You'll find a little SO post with some example code here: