[Rd] Change in grep behavior from 1.9.0 to R-patched

[Prof Brian Ripley]

On Fri, 11 Jun 2004, Martin Maechler wrote:

> >>>>> "Roger" == Roger D Peng <rpeng at jhsph.edu>
> >>>>>     on Fri, 11 Jun 2004 10:43:57 -0400 writes:
> 
>     Roger> I've noticed a change in the way grep() behaves between the 1.9.0 
>     Roger> release and a recent R-patched.  On 1.9.0 I get the following output:
> 
>     >> x <- dget(file = url("http://www.biostat.jhsph.edu/~rpeng/names.R"))
>     >> length(grep("^l\\w+tmean", x, perl = TRUE, value = TRUE))
>     Roger> [1] 84
> 
>     Roger> And on R-patched (2004-06-11) I get
> 
>     >> x <- dget(file = url("http://www.biostat.jhsph.edu/~rpeng/names.R"))
>     >> length(grep("^l\\w+tmean", x, perl = TRUE, value = TRUE))
>     Roger> [1] 13
> 
> I can reproduce this exactly.

Are you using a clean build of the current sources?

>     <....>
> 
>     Roger> I didn't find anything in the NEWs file that would indicate a change 
> 
> yes: The src/extras/pcre/ (Perl Compatible Regular Expressions)
>      library was upgraded, and since we assumed that wouldn't
>      have any effect --- as we now see, a too optimistically ---
>      it wasn't documented in NEWS

Eh?  It was upgraded before 1.9.0, and it is documented there as

INSTALLATION CHANGES

    o	The defaults for configure are now --without-zlib
	--without-bzlib --without-pcre.

	The included PCRE sources have been updated to version 4.5 and
	PCRE >= 4.0 is now required if --with-pcre is used.

The files date from 2004 Jan 11.

-- 
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