On Thu, 12 Aug 2004, Deepayan Sarkar wrote: > On Thursday 12 August 2004 10:19, Prof Brian Ripley wrote: > > On Thu, 12 Aug 2004, Deepayan Sarkar wrote: > > > On Thursday 12 August 2004 07:34, Prof Brian Ripley wrote: > > > > In R-devel, the Depends: field in the DESCRIPTION file is now > > > > used by library() to load the named packages before the current > > > > package, and also to set up the environment to save images and > > > > prepare for lazy loading. > > > > > > How would this relate to namespaces? For instance, lattice imports > > > grid (and a few things from stats and graphics). If I keep grid in > > > the depends field, loading lattice does a require(grid), which > > > defeats one of the purposes of having namespaces. If I leave it > > > out, nothing bad seems to happen as long as grid is installed, but > > > there should be some indication in the DESCRIPTION that that grid > > > is a requirement. None of the other fields seem appropriate. > > > > It's a grey area. As all copies of R that you are using will have > > grid, leave it out of Depends: for lattice. > > > > Perhaps we need to invent another field such as UsesNamespaces? > > That should work. > > Writing R Extensions says that > > `Packages that are necessary to successfully load the package using > library(pkgname) must be listed in the Depends field.' > > which no longer remains true.
Well, it was never true in the sense that it was frequently broken with impunity! One could argue it is still true, as package != namespace. > Ideally, it probably would have been > better to keep the old behaviour of Depends, and add the new > functionality in a new field, but I guess this way the majority of > packages can remain unchanged while being able to avail the new > features. Yes. I originally suggested 'EssentialPackages' and 'RequiredPackages', but was persuaded otherwise. Even then, it would be good to make clear the difference between needing a namespace to be loadable and needing a package attached. I can't think of any other example of one package only needing the namespace of another (contributed) package. Thanks for raising the issue. -- Brian D. Ripley, [EMAIL PROTECTED] 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 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
