Edna Bell wrote:> Dear R Gurus:
>
> What is the difference between a Primitive and a Generic, please?
>
>
They are talking about different things (though both look like
functions): generic talks about the user interface, primitive talks
about the internal implementation.
A generic is a function that will dispatch to a method, based on the
class (or classes, in the case of S4) of what gets passed to it.
A primitive is a way to implement internal functions in R. You can
write generic functions, but you need to modify the R source to write a
primitive. Details of the primitive implementation are in the R
Internals manual.
Duncan Murdoch