[R] Inheritance for S3 classes

[Bert Gunter]

The S3 class model isn't really a class model. It's more a way of
overloading functions. So it's rather simple, and there's less there
than you might be expecting. I always thought the "Object Oriented
Programming" chapter of the R language definition manual that ships
with R was a very good treatment. Have you tried there? If not, please
do so.

But surely you know how to search! (e.g. "S3 class system in R") --
there are many good tutorials on the internet. Also search at
rseek.org, which is "optimized" for R queries.

Cheers,
Bert




Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Mon, Aug 7, 2017 at 5:06 PM, Kym Nitschke <kym.nitschke at icloud.com> wrote:
> Hi R Users,
>
> I am relatively new to programming in R … so I apologise if my questions appear ‘dumb’.
>
> I am using a package that defines a number of S3 classes. I want to create an S3 child class of one of these classes. The parent class has a contractor with many arguments. I have been having difficulty writing the child class contractor. I have been unable to find a good reference in the internet for writing S3 classes. What I have been able to find out so far is that the child class constructor should call the parent class constructor … which in this case requires passing the argument list with a variable number of arguments (i.e. there are a number of optional arguments) from the child to the parent.
>
> So my first question is … is there an easy way to do this? The match.call function will return a call object .. however the attributes function when used on the call object returns a ‘NULL’.
>
> My second question is … can any one recommend a good reference for object oriented programming in R which includes a comprehensive discussion of the S3 class model?
>
> Thanks
>
> Regards,
>
> Kym
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