[Rd] Inherited Methods in r-devel (for package maintainers mainly)

[John Chambers]

These changes have been reverted (temporarily, I strongly hope) to sort 
out some incompatibilities with the Matrix recommended package.  They 
will be available on a branch for experimentation, once I sort out how 
to work with svn branches.

John

John Chambers wrote:
> A recently committed revison of R-devel (47740) has introduced a new 
> mechanism for ordering superclasses consistently, with related changes 
> for selecting inherited methods.
>
> As part of the process, a function testInheritedMethods has been  
> introduced that examines method selection for the relevant subclasses 
> and reports ambiguities.
>
> Maintainers of packages that have methods involving multiple arguments 
> are encouraged to run testInheritedMethods for the relevant generic 
> functions (e.g., the binary operators).  The new method selection is 
> unambiguous for single-argument selection.
>
> It's preferable  to find such ambiguities during package development 
> or revision, rather than having users encounter ambiguous method 
> selection later on.  In that spirit, ambiguous method selection is no 
> longer a warning, just a message.
>
> The new mechanism for class ordering and method selection is described 
> in a draft paper at 
> http://stat.stanford.edu/~jmc4/classInheritance.pdf (later likely to 
> be part of a submission to the R Journal).
>
> John
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>