(j3.2006) C interoperability idea from a colleague

[Bill Long]

On Apr 13, 2015, at 7:53 PM, Van Snyder <van.snyder at jpl.nasa.gov> wrote:

> A colleague would like to reference a Fortran subroutine that has
> several optional arguments from C.
> 
> I referred him to the "Further Interoperability" TS.
> 
> He asked if he had to provide a descriptor for every argument, not just
> the ones that are present.

Optional arguments that are not present are represented by a NULL pointer, not a descriptor.   

Cheers,
Bill


> 
> I said that's the way it is.
> 
> He suggested that the descriptor ought to include the Fortran argument
> name, and the called Fortran subroutine ought to work out which
> arguments are present.
> 
> I don't know whether that's practical, or not incompatible with what we
> did, but it is interesting.
> 
> 
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Bill Long                                                                       longb at cray.com
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Bioinformatics Software Development                     fax:  651-605-9142
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