From ripley at stats.ox.ac.uk  Mon Jul  4 14:08:38 2011
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Mon, 4 Jul 2011 13:08:38 +0100 (BST)
Subject: [Rd] Recent and upcoming changes to R-devel
Message-ID: <alpine.OSX.1.00.1107041124460.59432@tystie.local>

There was an R-core meeting the week before last, and various planned 
changes will appear in R-devel over the next few weeks.

These are changes planned for R 2.14.0 scheduled for Oct 31.  As we 
are sick of people referring to R-devel as '2.14' or '2.14.0', that 
version number will not be used until we reach 2.14.0 alpha.  You will 
be able to have a package depend on an svn version number when 
referring to R-devel rather than using R (>= 2.14.0).

All packages are installed with lazy-loading (there were 72 CRAN 
packages and 8 BioC packages which opted out).  This means that the 
code is always parsed at install time which inter alia simplifies the 
descriptions.  R 2.13.1 RC warns on installation about packages which 
ask not to be lazy-loaded, and R-devel ignores such requests (with a 
warning).

In the near future all packages will have a name space.  If the 
sources do not contain one, a default NAMESPACE file will be added. 
This again will simplify the descriptions and also a lot of internal 
code.  Maintainers of packages without name spaces (currently 42% of 
CRAN) are encouraged to add one themselves.

R-devel is installed with the base and recommended packages 
byte-compiled (the equivalent of 'make bytecode' in R 2.13.x, but done 
less inefficiently).  There is a new option
R CMD INSTALL --byte-compile
to byte-compile contributed packages, but that remains optional. 
Byte-compilation is quite expensive (so you definitely want to do it 
at install time, which requires lazy-loading), and relatively few 
packages benefit appreciably from byte-compilation.  A larger number 
of packages benefit from byte-compilation of R itself: for example AER 
runs its checks 10% faster.  The byte-compiler technology is thanks to 
Luke Tierney.

There is support for figures in Rd files: currently with a first-pass
implementation (thanks to Duncan Murdoch).

-- 
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



[Rd] Recent and upcoming changes to R-devel
Prof Brian Ripley