'CanMakeUseOf' field [was ".. Add 'fields' argument ..]

Duncan Murdoch writes:

On 8/29/2006 10:12 AM, Martin Maechler wrote:

"PaulG" == Paul Gilbert <pgilbert at bank-banque-canada.ca>
on Tue, 29 Aug 2006 09:55:09 -0400 writes:

...

The idea was a field related to but weaker than 'Suggests' :
Something like
'canMakeUseOf: <pkg1> [, <pkg2>, ... ]
which is *not* used in any QA/QC checking, but is purely
informative: If <pkg1> is require()able, then some examples may
look nicer, a function may provide another feature, etc, etc.
Alternatives to 'canMakeUseOf' would have been
'isHappilyCoworkingWith' ....

What do you (R-devel listeners) think about the idea?

Thanks, Paul.
As you may have guessed I should have put a  " :-) "  beside the
'isHappily...' .

Of course, even 'CanMakeUseOf' {we should capitalize the first letter}
is rather too long, but before finding the proper term, we should
agree on usefulness of such a new field.
Apart from the use of package authors {some could note that
other packages make use of theirs, without already depending on
or suggesting them}, it's one of those fields that should help
in the future to explore (e.g. cluster or neighborhood-graph)
the growing high-dimensional space of R packages.

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.

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.)