[J3] Vector subscripts and INTENT(INOUT)

Malcolm Cohen malcolm at nag-j.co.jp
Thu May 17 21:23:52 EDT 2018

I wrote:

> You won’t be getting any rules that require time travel reinserted into the standard.

Bill claims:

>The current text … also appears to have a timing characteristic


Of course it does.  It is exactly the same “timing” characteristic that applies ALWAYS to dummy arguments with unspecified intent, that the definability depends on the actual argument.


This is not even a forward reference in time, but a reference to the current state; obviously that does not involve time travel and cannot violate causality.


> And that a different reference to the same procedure with a named array as the actual argument does not carry the requirement that the dummy be not definable. 

Well if that named array is a constant, or a non-definable variable such as a dummy array associated with an expression, the dummy argument is again, not definable.  This even applies to scalars, not just arrays!  So if you have a problem with referring to the actual argument “because timing”, you have a problem with bog-standard FORTRAN 77 rules.


However, obviously if the actual argument is not a vector-subscripted object, the text beginning “if the actual argument is a vector-subscripted array section” is not in play.  There is literally no other interpretation of “If condition then consequence” than that the consequence is not implied when the condition is false.


> This seems like more effort


There is no “more effort”.  You just have to keep doing the same things you’ve been doing for the last 25 years.  There is literally No Change to the Intention of the semantics, we’ve just said it without involving time travel!


Talk about making a mountain out of a perfectly flat plane; there is not even a molehill in sight.




..............Malcolm Cohen, NAG Oxford/Tokyo.


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