Seth Falcon wrote:
> Thomas Petzoldt <[EMAIL PROTECTED]> writes:
>> One odd thing I found was that initialize does obviously not allow to
>> incorporate additional named parameters which are not slots.
>
> ?! Does for me:
Your example works but one can not arbitrarily mix slots, other named
arguments and the default callNextMethod(). The documentation states:
"... Data to include in the new object. Named arguments correspond to
slots in the class definition."
Here is my example (extended from yours):
setClass("FOO", representation(x="numeric", y="numeric"))
setMethod("initialize", "FOO",
function(.Object, y, value) {
callNextMethod()
[EMAIL PROTECTED] <- value * 2
.Object
})
new("FOO", y=1, value=2)
An object of class "FOO"
Slot "x":
[1] 4
Slot "y":
numeric(0)
What is different from what I originally expected. In such cases one has
to add the arguments to callNextMethod(y=1) explicitly.
>> In essence I think that one should not use the constructor approach
>> (from 2001) anymore, even if the "call is independent of the details
>> of the representation".
>
> Sometimes both are useful. You can have convenience generator
> functions for users, but have initialize methods that get called
> internally. This can also be nice in that the internal code can be
> lean, while common user-facing code can do lots of error and sanity
> checking, etc.
I see, and for the moment I let the constructors in the package, but
they only provide now some class specific defaults and then call the
(inherited) initialize method via new.
Thomas
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
