[Rd] Re: Packages and Libraries (was: Re: lme4 "package" etc ..)

[Kurt Hornik]

>>>>> Peter Dalgaard writes:

> Kurt Hornik <Kurt.Hornik at wu-wien.ac.at> writes:
>> >>>>> A J Rossini writes:
>> 
>> > But I don't see a problem with "package("package")", though I'm sure
>> > I'm missing something.
>> 
>> package() [sic] might be the creator for package objects, provided we
>> can decide on what they are (and what kind of packages [source,
>> installed, ...] they are used for).
>> 
>> usePackage() or use_package() otoh would indicate to "use" a package
>> (i.e., load and attach it).  The tricky part is deciding about the
>> interface (e.g., finally disallowing non-standard evaluation as it is a
>> programmer's nightmare) and what it should return.  And that is work in
>> progress ...

> Any information on the rate...? (I still vote for usepackage() btw.)

Why not use(), as the GCD?

> It would be good if we could at least have an outline of the intended
> functionality and see if we could forge ahead and get a preliminary
> version done in time for 2.1.x

Help us out.

	use <- function(package, pos = 2, lib.loc, ...)

where 'package' is either a character string or some sort of package
object/reference, to be specified later.  And 'lib.loc' needs to have a
different name if we rename libraries into stores or whatever ...

What should this return?  Currently, 'library' returns the list of
loaded (or available) packages by default, as a list of names, which is
not good enough.  So we need something like the DLLInfoList returned by
getLoadedDLLs() (and the docs should actually mention that class), or
something usable by the package management tools ... and this is under
redesign as well.

But why should this really return info on all loaded/attached packages?
An alternative might be just returning the package meta-data in some
form.  Or nothing, which would fit into the idea that it really does
nothing apart from loading and attaching a package.

(And maybe a condition object inheriting from packageLoadAndAttachError
in case of failure? :-))

-k