I see the logic, but it seems in practice people often write specific
methods with their own specific arguments. (Think of the many plot or print
methods for different objects, for example.) Here, enforcing a ... argument
does not buy us much. All that we really need is that plot(x) will work for
m
... also, the only reason non-generic functions using ellipsis can throw an
error when an argument is not used is that they keep passing ... on to
functions that recursively encounter fumctions that eventually do not accept an
ellipsis argument. If the function calls a generic with an ellipsis a
R encourages the use of ... particularly in S3 generics, to avoid
over-depending on inheritance to enable flexible use of these generics. That
is, when you call the generic without knowing which class you are giving it,
you cannot specify class-specific arguments. However, some methods have obvi
Hi Jeff,
I wouldn't say R encourages that in general. Non-generic functions will
throw an error if you use a non-existent argument. And some generic
functions check for it:
seq(1, 3, blah = 1)
[1] 1 2 3
Warning message:
In seq.default(1, 3, blah = 1) :
extra argument ‘blah’ will be disregarded
You seem to think this is a bad thing. R does encourage lenient argument
checking... what rock have you been under for the last 20 years?
On March 8, 2020 5:41:51 AM PDT, David Hugh-Jones
wrote:
>You're quite right :-) But I think the polemic still holds, because I
>have
>to add manual argument
You're quite right :-) But I think the polemic still holds, because I have
to add manual argument checking to all my methods, which has a cost in
lines of code. Indeed, few base R methods have chosen to do this. In
effect, the current setup encourages writing methods with "lenient"
argument specifi
You can add the ... argument to chop.default(), and then check that
length(list(...)) is zero.
Also, you might be interested in the ellipsis package.
Gabor
On Sun, Mar 8, 2020 at 10:56 AM David Hugh-Jones
wrote:
>
> Hi all,
>
> My package defines the following method and generic:
>
> chop <- fu
Hi all,
My package defines the following method and generic:
chop <- function (x, ...) UseMethod("chop")
chop.default <- function (x, breaks, labels, extend = NULL, drop = TRUE) {
... }
R CMD check then gives a warning:
W checking S3 generic/method consistency (695ms)
chop:
function(x
