On Tue, 5 Feb 2008, Barry Rowlingson wrote: > Duncan Murdoch wrote: > >> Another problem is that there are two different class systems in R: >> sometimes calls S3 and S4 (because of the versions of S where they were >> introduced). You were reading about S3. > > There's three different class systems if you also include the R.oo > add-on package[1]. Even perl, the language seemingly founded on the > concept of TMTOWTDI[2], only has the one OOP system. > You need to be a bit careful here. R has two object systems, S3, and S4, that are supported in the R internals to allow methods for things like `+` to be written. In addition, R is rich enough as a language to allow users to develop their own object systems if they choose. The fact that there are two internally supported systems is not ideal. On the other, the fact that users can write their own and have done so is a feature.
luke > Barry > > [1] http://www1.maths.lth.se/help/R/R.oo/ > [2] There's More Than One Way To Do It > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Luke Tierney Chair, Statistics and Actuarial Science 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: [EMAIL PROTECTED] Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
