[Rd] calling setGeneric() twice

Seth Falcon seth at userprimary.net
Tue Jan 19 19:05:16 CET 2010


On 1/19/10 10:01 AM, Ross Boylan wrote:
> Is it safe to call setGeneric twice, assuming some setMethod's for the
> target function occur in between?  By "safe" I mean that all the
> setMethod's remain in effect, and the 2nd call is, effectively, a no-op.
>
> ?setGeneric says nothing explicit about this behavior that I can see.
> It does say that if there is an existing implicity generic function it
> will be (re?)used. I also tried ?Methods, google and the mailing list
> archives.
>
> I looked at the code for setGeneric, but I'm not confident how it
> behaves.  It doesn't seem to do a simple return of the existing value if
> a generic already exists, although it does have special handling for
> that case.  The other problem with looking at the code--or running
> tests--is that they only show the current behavior, which might change
> later.
>
> This came up because of some issues with the sequencing of code in my
> package.  Adding duplicate setGeneric's seems like the smallest, and
> therefore safest, change if the duplication is not a problem.

I'm not sure of the answer to your question, but I think it is the wrong 
question :-)

Perhaps you can provide more detail on why you are using multiple calls 
to setGeneric.  That seems like a very odd thing to do.

+ seth

-- 
Seth Falcon | @sfalcon | http://userprimary.net/user



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