[Rd] Re: [R] Nothing can be pasted...

[Luke Tierney]

Peter Dalgaard BSA wrote:
> Prof Brian Ripley <ripley@stats.ox.ac.uk> writes:
> 
> > > which I didn't see with RH6.2. However,  R  seems to run just fine
> > > nevertheless. The offending line in config.h is
> > > 
> > > #define DYNLOADEXT  "." ## SHLIBEXT
> > > 
> > > I'm not too familiar with  C  programming, but if ## SHLIBEXT
> > > is meant as a comment, shouldn't it be surrounded by /* */?
> > 
> 
> > I wonder if this is a problem with using a beta compiler?
> 
> I certainly wouldn't put such a goof beyond RedHat, but it might be a
> question of tighter standards compliance. What happens if the spaces
> around ## are removed? (The error message might read as "can't paste
> onto a whitespace token")
> 

White space should be fine, from my reading of Harbison & Steele at least.
The old KR way of doing token concatenation was

#define CONCAT(x,y) x/**/y

and there leaving white space would not work, but with the ## operator

#define CONCAT(x,y) x##y

and

#define CONCAT(x,y) x ## y

should be equivalent.

Since the two bits are literal strings, it would also be possible to define

#define DYNLOADEXT  "." SHLIBEXT

My fear is that the preprocessor is complaining about SHLIBEXT being
defined but empty because of a configure problem.

luke


-- 
Luke Tierney
University of Minnesota                      Phone:           612-625-7843
School of Statistics                         Fax:             612-624-8868
313 Ford Hall, 224 Church St. S.E.           email:      luke@stat.umn.edu
Minneapolis, MN 55455 USA                    WWW:  http://www.stat.umn.edu
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._