[R-pkg-devel] Acknowledging small functions from another package

[Duncan Murdoch]

On 04/05/2023 4:53 a.m., Ivan Krylov wrote:
> On Thu, 4 May 2023 09:21:17 +0100
> David Hugh-Jones <davidhughjones using gmail.com> wrote:
> 
>> One of my packages copy-pasted some small functions (stuff like
>> `%||%` for is.null) from ggplot2. (Both packages are MIT-licensed.)
>>
>> What is an appropriate way to acknowledge this in the DESCRIPTION
>> Author: or Authors using R section?
> 
> One way would be to mention Hadley Wickham:
> https://github.com/tidyverse/ggplot2/commit/ef2f944863a0db8841bf628e9eb4a9faef5049e6#diff-8f53135445ab98749043fa52e438346bb9acae8e0185aa95f186d0aa021bb7e0
> (`git blame` will also tell you that he later moved this function to a
> different file).
> 
> I think that person('ggplot2 authors', role = 'cph', comment = 'The
> %||% operator') is also fine, just like e.g. unitizer package mentions
> the code taken from R itself.
> 
> You can also find this operator in multiple base R packages, currently
> unexported (maybe some day...). They mention in the comments that the
> operator is adapted from ggplot2.

I'd probably use role = "ctb" instead for "ggplot2 authors", and include 
Posit PBC as a copyright holder (as ggplot2 does).  Presumably you or 
others are also copyright holders for your package and should also have 
role = "cph" added so it doesn't give the impression that Posit owns 
everything.

Duncan Murdoch