[Rd] Methods dispatched on "..."
jmc at r-project.org
Mon Aug 11 18:14:43 CEST 2008
A new facility has been committed for version 2.8.0 that allows S4
generics to be defined with "..." as the signature.
Methods are then defined with a single class in the signature. The
interpretation is that the method will be selected and called when all
the arguments matching "..." are from the specified class, or some
subclass of that class. See ?dotsMethods for details.
The current implementation is a test. It's dispatch is done in R code,
as described in the documentation. Once the desired semantics are
clear, it's a natural candidate for adding to the current C dispatch
code. Also, in this version "..." cannot be combined with other
arguments in the generic function's signature. This is also not a total
necessity and might be relaxed, after the dispatch is rewritten.
Please play with it, if it sounds useful.
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