[J3] Limitations of SELECT RANK?

[Bill Long]

If you call  generic SUB without knowing the rank of arr at compile time, which of the 3 specifics do you call? 

I don’t see how the IF version could work. 



> On Oct 19, 2020, at 9:38 PM, Malcolm Cohen via J3 <j3 at mailman.j3-fortran.org> wrote:
> 
> It’s exactly identical to
>  
>    IF (RANK(arr)>=1 .AND. RANK(arr)<=3) CALL SUB(arr)
>  
> There is no “limitation” in SELECT RANK here.
>  
> Cheers,
> -- 
> ..............Malcolm Cohen, NAG Oxford/Tokyo.
>  
> From: J3 <j3-bounces at mailman.j3-fortran.org> On Behalf Of Clune, Thomas L. (GSFC-6101) via J3
> Sent: Tuesday, October 20, 2020 1:24 AM
> To: General J3 interest list <j3 at mailman.j3-fortran.org>
> Cc: Clune, Thomas L. (GSFC-6101) <thomas.l.clune at nasa.gov>
> Subject: [J3] Limitations of SELECT RANK?
>  
> I recall that when J3 was discussing one of the SELECT RANK papers for F2018,  I had asked whether something like this was possible:
>  
> Consider the construct:
>  
> SELECT RANK (arr)
> RANK (1)
>     CALL SUB(arr))
> RANK (2)
>     CALL SUB(arr))
> RANK (3)
>     CALL SUB(arr))
> RANK DEFAULT
> END SELECT RANK
>  
> where SUB() is a generic interface that is  suitably overloaded for the relevant ranks.
>  
> Could the feature be extended to allow the equivalent:
>  
> SELECT RANK (arr)
> RANK(1:3)
>     CALL SUB(arr)
> RANK DEFAULT
> END SELECT RANK
>  
> My memory is that there was a resounding “NO” in the room (presumably mostly by the vendors).       I would very much appreciate it if someone knowledgable about why that is not workable could respond on the thread below.       
>  
> https://github.com/j3-fortran/fortran_proposals/issues/185
>  
> Or if preferred, they could respond to me directly and I can summarize in the GitHub discussion.  (With or without attribution depending on preference.)
>  
> Thanks,
>  
> - Tom
>  
>  
>  
>  
>  
> 
>  
>  
> 
> Disclaimer
> The Numerical Algorithms Group Ltd is a company registered in England and Wales with company number 1249803. The registered office is: Wilkinson House, Jordan Hill Road, Oxford OX2 8DR, United Kingdom. Please see our Privacy Notice for information on how we process personal data and for details of how to stop or limit communications from us.
> 
> This e-mail has been scanned for all viruses and malware, and may have been automatically archived by Mimecast Ltd, an innovator in Software as a Service (SaaS) for business.

Bill Long                                                                       longb at hpe.com
Engineer/Master , Fortran Technical Support &   voice:  651-605-9024
Bioinformatics Software Development                      fax:  651-605-9143
Hewlett Packard Enterprise/ 2131 Lindau Lane/  Suite 1000/  Bloomington, MN  55425