From maechler at stat.math.ethz.ch  Tue Aug 29 10:44:59 2006
From: maechler at stat.math.ethz.ch (Martin Maechler)
Date: Tue, 29 Aug 2006 10:44:59 +0200
Subject: [Rd] PATCH: Add fields argument to installed.packages and
	available.packages
In-Reply-To: <m2wt8sgyo0.fsf@ziti.fhcrc.org>
References: <m2wt8sgyo0.fsf@ziti.fhcrc.org>
Message-ID: <17651.65163.240840.365787@stat.math.ethz.ch>

>>>>> "Seth" == Seth Falcon <sfalcon at fhcrc.org>
>>>>>     on Mon, 28 Aug 2006 17:42:39 -0700 writes:

    Seth> Hi all, The write_PACKAGES function has a 'fields'
    Seth> argument that allows a user generating a PACKAGES file
    Seth> to specify additional fields to include.  For
    Seth> symmetry, it would be nice for the available.packages
    Seth> function to be able to read those extra fields when
    Seth> specified.

    Seth> Similarly, it would be useful for installed.packages
    Seth> to have a 'fields' argument.  This would allow a user
    Seth> to query the set of installed packages for other
    Seth> fields in the DESCRIPTION file.

    Seth> One use for this would be for repository hosters to
    Seth> include the License field in their PACKAGES file.  In
    Seth> this way, end users could query a repository and only
    Seth> download packages that they have a license to use.

    Seth> Below is a patch against svn 38996 that attempts to
    Seth> implement this.

I like the idea and will look into applying the patch
(note there's at least one typo which makes "make check" fail:
 /priotiry/)

A propos:

A while back (in last summer?), we (some of R-core) have
discussed about a new field to be added to DESCRIPTION,
and AFAIR, the only problem we had, is to find a name we
all liked.
Or was there more then the name alone, and some where convinced
that it is superfluous and hence too complicated.

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?

Martin




[Rd] PATCH: Add fields argument to installed.packages and available.packages
Martin Maechler