[Rd] how to add method to .Primitive function
simon.urbanek at r-project.org
Sat May 7 21:33:49 CEST 2005
On May 7, 2005, at 2:59 PM, Vadim Ogranovich wrote:
> But then mylist is not a list:
>> x <- new("mylist", x = list(x = 1, y = 2))
> Error in x[] : subscript out of bounds
> This is probably solvable by a sprinkle of setIs or setAs spells, but
> each time I get into the S4 area I feel walking a mine-field.
Well, then you can still use S3:
x <- list(x=1:5, y=5:1)
class(x) <- "mylist"
dim.mylist <- function(l) c(length(l[]),length(l))
 5 2
 1 2 3 4 5
I'm not saying it's a good idea, because you can still break other
things if you're not careful, but it's possible... If all you want is
writing convenience functions for lists, that's fine, but I don't
think you can replace data frames with such objects easily ...
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