[Rd] couldn't find function "setClass"

[Martin Maechler]

>>>>> "BDR" == Prof Brian Ripley <ripley at stats.ox.ac.uk>
>>>>>     on Wed, 17 Sep 2003 07:05:57 +0100 (BST) writes:

    BDR> On Tue, 16 Sep 2003, John Chambers wrote:

    <..............>


      JMC> That (apparently) the problem arises in such a
      JMC> special situation is confusing for users.  At least
      JMC> for me, it's ONLY in the combination of saved image
      JMC> and no namespace.

      JMC> That the user does not need a require(methods) when
      JMC> testing the code directly but does (sometimes) when
      JMC> the source code is in package source is not a
      JMC> feature.  If we can avoid this complexity, that would
      JMC> encourage package developers.

     BDR> Unfortunately, it is not necessarily true that
     BDR> require(methods) is not needed when testing: site
     BDR> admins or "users" might have changed the default
     BDR> packages from the system default.

    JMC> Indeed, but then the user would always see things this
    JMC> way.  Consistency makes people feel more secure.

     BDR> Otoh, once we use --vanilla for the save image
     BDR> creation, it seems that this eliminates all
     BDR> (reasonable) possibilities for changing the default
     BDR> packages (or am I missing something?).  So we could
     BDR> use the system default rather than just base here.

    JMC> Intuitively, --vanilla means "the standard flavor", as opposed to
    JMC> --stripped, say, so it would seem more natural to have the system
    JMC> defaults wherever possible.

  BDR> As I have said before, --vanilla does not change the
  BDR> default packages, nor the possibility of setting the
  BDR> default packages at system level.

  BDR>	     gannet% env R_DEFAULT_PACKAGES=ts R --vanilla

  BDR> really does load only "package:ts".

  BDR> From ?Startup

  >> The command-line flag '--vanilla' implies
  >> '--no-site-file', '--no-init-file', '--no-restore' and
  >> '--no-environ'.

  BDR> and let me add, nothing else.  It is possible for
  BDR> sysadmins to change the system environment and profile
  BDR> files, and some do.

Agreed.  
So this means we should do more than just "--vanilla".
In some cases, we already do set environment variables such as
LANG=C and so we should also be allowed to set
R_DEFAULT_PACKAGES to the standard default (rather than the
local installation one).

Martin