'CanMakeUseOf' field
Duncan Murdoch <murdoch at stats.uwo.ca> writes:
I think we need an option to R CMD check rather than a new field in the DESCRIPTION. Currently a package could be mentioned for any of these reasons: 1. To make functions, examples or vignettes work 2. To allow optional functionality in functions, examples or vignettes. 3. Because it contains complementary functions. I don't think we really need to worry about 3: it should be contained in 1 or 2, if reasonably complete examples are given. Case 1 is handled by Depends.
I think there is an important distinction between a dependency needed for the package to function and a dependency needed to demonstrate said functionality via an example or vignette. The former is what Depends is about, the latter is something else (Suggests).
An author should check case 2 both with and without the suggested package. A user might be satisfied with a simple check "as things currently stand", or might want a stringent check like the author wants. The author can't know that, because it will depend on the user. So I don't think this is something that should be changed in DESCRIPTION. There should be an option to R CMD check to include or exclude packages mentioned in the Suggests entry. (I'd suggest a 3 level option: check as though they are not available, check as currently installed, require that they be available.)
I like this approach and agree in general that a solution involving changes to R CMD check might be the best as opposed to adding fields. + seth