R devel - Jun 2008 - Splus/R typedef for C equivalent of S "integer"

We've been working on making it easier to write
packages that work in both R and Splus.  One issue
is that R and Splus use different internal representations
of integers and this makes a difference on their 64-bit
versions: R uses ints (32 bits on 32-bit and 64-bit versions
of R) and Splus uses longs (32 bits on 32-bit Splus and
64 bits on 64-bit Splus).  The obvious ways to deal with
the difference are to use a typedef or a #define to map
those to a common name.  I think it would be handy to
put this definition into R.h or some other R header file
(Splus now has an R.h and other header files with the R
names that we recommend for all package work.)

Should this be a typedef or a #define?  What should its
name be?

There is a file, RSCommon.h (from omegahat?), that I've seen
in a few packages which uses a typedef, RSInt, for this.
Repeated typedefs, even with the same definition, are illegal
so putting typedef ... RSInt into R.h would break those packages.
(C doesn't yet have an if-typedef-exists or untypedef construct,
does it?)

I like XXXinteger, since it refers to the R/Splus name of
the class, "integer", instead of the C-like name.  Should
the "XXX" prefix be "RS" or "RSplus" or
"S"?

I like typedefs since you can use them in the debugger.
Should a typedef be accompanied by a #define XXXinteger_defined
so one can write code that works on older versions of R or
Splus without the typedef?

I think R.h would be a good place for it, but I don't
have strong feeling about that one.

If we can come to a consensus on the name, typedef/#define,
and which *.h file, I can put it into Splus.

----------------------------------------------------------------------------
Bill Dunlap
Insightful Corporation
bill at insightful dot com

 "All statements in this message represent the opinions of the author and
do
 not necessarily reflect Insightful Corporation policy or position."

Bill,

R's R.h already has

typedef double Sfloat;
typedef int Sint;
#define SINT_MAX INT_MAX
#define SINT_MIN INT_MIN

for this purpose, and it is used in a lot of packages.

It goes back a long way, and I don't remember its origins but 'S 
Programming' is one source.

Brian

On Wed, 4 Jun 2008, Bill Dunlap wrote:
> We've been working on making it easier to write
> packages that work in both R and Splus.  One issue
> is that R and Splus use different internal representations
> of integers and this makes a difference on their 64-bit
> versions: R uses ints (32 bits on 32-bit and 64-bit versions
> of R) and Splus uses longs (32 bits on 32-bit Splus and
> 64 bits on 64-bit Splus).  The obvious ways to deal with
> the difference are to use a typedef or a #define to map
> those to a common name.  I think it would be handy to
> put this definition into R.h or some other R header file
> (Splus now has an R.h and other header files with the R
> names that we recommend for all package work.)
>
> Should this be a typedef or a #define?  What should its
> name be?
>
> There is a file, RSCommon.h (from omegahat?), that I've seen
> in a few packages which uses a typedef, RSInt, for this.
> Repeated typedefs, even with the same definition, are illegal
> so putting typedef ... RSInt into R.h would break those packages.
> (C doesn't yet have an if-typedef-exists or untypedef construct,
> does it?)
>
> I like XXXinteger, since it refers to the R/Splus name of
> the class, "integer", instead of the C-like name.  Should
> the "XXX" prefix be "RS" or "RSplus" or
"S"?
>
> I like typedefs since you can use them in the debugger.
> Should a typedef be accompanied by a #define XXXinteger_defined
> so one can write code that works on older versions of R or
> Splus without the typedef?
>
> I think R.h would be a good place for it, but I don't
> have strong feeling about that one.
>
> If we can come to a consensus on the name, typedef/#define,
> and which *.h file, I can put it into Splus.
>
>
----------------------------------------------------------------------------
> Bill Dunlap
> Insightful Corporation
> bill at insightful dot com
>
> "All statements in this message represent the opinions of the author
and do
> not necessarily reflect Insightful Corporation policy or position."
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
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