[R] S3 generics need identical signature?

Henrik Bengtsson hb at stat.berkeley.edu
Mon Jun 21 17:42:29 CEST 2010


On Mon, Jun 21, 2010 at 4:23 PM, Gábor Csárdi <csardi at rmki.kfki.hu> wrote:
> On Mon, Jun 21, 2010 at 4:17 PM, Duncan Murdoch
> <murdoch.duncan at gmail.com> wrote:
> [...]
>> The requirement is that the methods need to have signatures that contain all
>> the arguments of the generic.  If the generic includes ..., then the methods
>> can add other arguments, too.  So with the generic for plot() as you show
>> above, any plot method is required to have x and y as the first two
>> arguments, and ... as an argument, but they can have other args too.
>
> This makes sense, and it is actually great! Thanks a lot for the explanation.

FYI, the most "generic" way you can write a generic function is:

foo <- function(...) UseMethod("foo");

/Henrik
>
> Best Regards,
> Gabor
>
> [...]
>
>
> --
> Gabor Csardi <Gabor.Csardi at unil.ch>     UNIL DGM
>
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