[Rd] Package "datasets" not exporting anything on a recent R-2.15.1-patched
Prof Brian Ripley
ripley at stats.ox.ac.uk
Sun Aug 26 19:03:29 CEST 2012
On 26/08/2012 17:25, Laurent Gautier wrote:
> I just stumbled on the following apparent oddity: the package "datasets"
> does not appear to export anything out of its namespace:
> > ns_datasets <- getNamespace('datasets')
> > getNamespaceExports(ns_datasets)
> Not the case with other packages (example here with "utils"):
> > ns_utils <- getNamespace('utils')
> > head(getNamespaceExports(ns_utils))
>  "?" ".DollarNames" "adist" "alarm" "apropos"
>  "aregexec"
> Is this a temporary glitch, or is there something new and specific to
> "datasets" ?
Not new, been so since R 2.14.0.
The package contains no R code: the only reason it has a namespace is
that since 2.14.0 all packages must have one.
There are other data-only packages, but not in base R.
Lazy-loaded data has not been part of the namespace for a long time:
they are directly in the package's environment. The reason is the
namespace scoping rules: if the package's datasets were in its
namespace, they would be found before any other dataset of that name by
the package's R functions.
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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