[R-pkg-devel] A function in one of my package is now a method in base R

[Shu Fai Cheung]

Thanks a lot for both suggestions! I haven't thought about these
approaches, They may solve my problem without breaking existing code.
I may just keep the original arguments for backward compatibility.
Coincidentally, "object" and "by" have the same meanings as "x" and
"y" in base::sort_by() and so the matching makes sense.

Regards,
Shu Fai Cheung

On Sat, Aug 3, 2024 at 7:13 PM Deepayan Sarkar
<deepayan.sarkar using gmail.com> wrote:
>
> I haven't thought about this carefully, but shouldn't this mostly work?
>
>   sort_by.est_table <- function(x, y = c("op", "lhs", "rhs"),
>     object = x,
>     by = y,
>     op_priority = c("=~", "~", "~~", ":=", "~1", "|", "~*~"),
>     number_rows = TRUE, ...) {
>
> <code unchanged>
>
> }
>
> -Deepayan
>
> On Sat, 3 Aug 2024 at 00:13, Duncan Murdoch <murdoch.duncan using gmail.com> wrote:
>>
>> On 2024-08-02 10:35 a.m., Shu Fai Cheung wrote:
>> > Hi All,
>> >
>> > I have a function (not a method), sort_by(), in one of my packages. A
>> > new method with the same name was introduced in the recent versions of
>> > R (4.4.0 or 4.4.1, I forgot which one), resulting in potential
>> > conflict in users' code.
>> >
>> > Certainly, users can simply use pkg_name::function_name() to solve the
>> > conflict. However, I would like to be consistent with base R and so I
>> > am thinking about converting my function to a method for the class for
>> > which my function is intended to work on (e.g, est_table).
>> >
>> > However, my function has arguments different from those in the base R sort_by():
>> >
>> > Base R:
>> >
>> > sort_by(x, y, ...)
>> >
>> > My function:
>> >
>> > sort_by(
>> >    object,
>> >    by = c("op", "lhs", "rhs"),
>> >    op_priority = c("=~", "~", "~~", ":=", "~1", "|", "~*~"),
>> >    number_rows = TRUE
>> > )
>> >
>> > If I write the function sort_by.est_table(), I would need to match the
>> > argument names of the base R sort_by(). However, I think it is a bad
>> > idea to rename the arguments in my function and it will break existing
>> > code.
>> >
>> > Any suggestions on how I should proceed? Is keeping my function as-is
>> > a better option? Name conflict is not unusual across packages and so
>> > users need to learn how to solve this problem anyway. Nevertheless, if
>> > possible, I would like to solve the conflict internally such that
>> > users do not need to do anything.
>>
>> I think it's impossible to avoid some inconvenience to your users.
>>
>> Here's what I'd suggest:
>>
>> - Create a method for base::sort_by(), as you suggested you could.  Use
>> the generic's variable names for compatibility, but also add your extra
>> variable names as additional arguments, e.g.
>>
>>   sort_by.est_table <- function(x, y, object,
>>     by = c("op", "lhs", "rhs"),
>>     op_priority = c("=~", "~", "~~", ":=", "~1", "|", "~*~"),
>>     number_rows = TRUE, ...) {
>>
>>    # This test seems unlikely:  how would we have dispatch here if we
>> specified object explicitly?
>>
>>    if (!missing(object) {
>>      if (!missing(x))
>>        stop("both x and object specified!")
>>      x <- object
>>    }
>>
>>    # This one is more likely to do something:
>>
>>    if (!missing(by)) {
>>      if (!missing(y))
>>        stop("both y and by specified!")
>>      y <- by
>>    }
>>
>>    # Now proceed using x and y
>>
>>    ...
>> }
>>
>> - Create a separate function, e.g. sort_by_old() which is exactly
>> compatible with your old sort_by().  For users where the above doesn't
>> just work, they can switch to sort_by_old().
>>
>> Duncan Murdoch
>>
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