[Info-vax] Roadmap

[gezelter at rlgsc.com]

On Sunday, January 6, 2019 at 12:16:48 PM UTC-5, Arne Vajhøj wrote:
> On 1/6/2019 11:16 AM, gezelter at rlgsc.com wrote:
> > In the case of floating point, perhaps all (repeat ALL) OpenVMS
> > compilers should support a non-standard keyword "IEEE754" as an
> > adjunct to REAL and DOUBLE. A "C"-ish example would be:
> > 
> > IEEE754 float X; IEEE754 double Y;
> > 
> > in FORTRAN:
> > 
> > IEEE754 REAL*4 X; IEEE754 REAL*8 Y;
> > 
> > This would allow the clarity in documenting mixed representation
> > programs, e.g., programs which read/write one format while working
> > internally in another. Often, such situations are, as I have noted
> > elsewhere, not a voluntary choice. Historical data exists, libraries
> > expect certain formats, etc.
> > 
> > Doing this consistently across multiple compilers is, I admit, a
> > chore. However, it is also a problem best addressed in a consistent
> > manner, than ad hoc for each different compiler.
> > 
> > My apologies to John for adding to his work queue.
> 
> It would also make the code non-portable.
> 
> Probably not a problem for Basic, Pascal etc..
> 
> But for C, Fortran etc. then I see it as a problem.
> 
> Arne

Arne,

Having written a large amount of portable code over the years, I can assure you that portability (to different platforms) is not an issue in these cases. 

However, the need that I noted is very common. Data compatibility is frequently needed, and data morphing is a common need.

In some languages (e.g., C/C++) the portability issue can be handled with lexical macros.

- Bob Gezelter, http://www.rlgsc.com