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

[Kurt Hornik]

>>>>> A J Rossini writes:

> On Tue, 8 Feb 2005 23:05:20 +0000 (GMT), Prof Brian Ripley
> <ripley at stats.ox.ac.uk> wrote:
>> On Tue, 8 Feb 2005 Ted.Harding at nessie.mcc.ac.uk wrote:
>> 
>> [...]
>> 
>> > But, a propos, is there an R entity called a "library"
>> > (other than the command) as distinct from a "package"?
>> 
>> Yes.  That is what the argument 'lib.loc' to library() and other functions
>> refers to.
>> 
>> A 'library' is a collection of packages stored in one directory.
>> 
>> library("pkg") means `go to one or more libraries, find package pkg and
>> load it up'

> And this is the problem, that the description doesn't clearly match
> the specification.

> One might easily expect that library("pkg") implies use library "pkg"
> for further package loading.

> It's almost too bad that libraries weren't books, with packages being
> chapters, or libraries being postOffices, with packages being
> packages, or packages being libraries, with libraries being cities or
> libraries being libraries, with packages being books.

> But the current mess wastes a good bit of time aggravating people who
> want things just so, responding to people who are just careless.

As I wrote earlier, we need to have alternatives to change this.

The R system is highly extensible through standardized add-ons called
*packages*.  That is one of its key strengths, and I don't think we
should stop referring to packages as packages.

Packages are made available by putting them into *libraries*, defined as
"places where R knows to find packages".  If we do not like this term,
we need a better one.

Packages are loaded and attached using library(), which in principle is
something for which a replacement is desired anyways.  But as Brian and
I [at least] said, we need not only a new name, but also a careful
redesign, and someone taking charge.

-k