(j3.2006) Select Rank
Van Snyder
van.snyder
Wed Feb 18 17:57:15 EST 2015
Bill Long wrote:
> On Feb 18, 2015, at 2:55 PM, Van Snyder <van.snyder at jpl.nasa.gov> wrote:
>
>
>> SELECT RANK would need two different forms if we were to allow it both for
>> assumed-rank and known-rank entities.
>>
>
> For SELECT TYPE, we allow only polymorphic selectors. I see no valid reason for allowing anything other than assumed-rank selectors for SELECT RANK. The current consensus to borrow from SELECT TYPE and use an associate name, and include the selector in a SELECT RANK statement in the list of allowed uses of assumed-rank, seems clean and simple. Lets keep it that way.
>
The only reason to allow SELECT RANK for known-rank entities is its
potential use in INCLUDE files, where one doesn't know the rank of
objects whose names appear within the file. I believe 04-195 is a
superior solution to these problems.
The case I had, where I need the first element of an object whose name
appears in an INCLUDE file, would be handled by allowing A(lbound(a)) as
a subscript. LBOUND(A) has the same extent as the rank of A, so (at
least in this case) one wouldn't even need a RANK intrinsic function.
Without 04-195, one needs different syntax for every rank, which brings
us back to SELECT RANK for known-rank objects.
That leaves the problem of specifying the shape of the <selector> in a
CASE block in a SELECT RANK construct -- if we decide to do it at all.
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