(j3.2006) Proposals 13 and 17 in 13-244r1

[Malcolm Cohen]

>Proposal 13 in 13-244r1 deals with conditional expressions.  The second
>functionality is a form that allows to compute whether an actual
>argument is present.  This should be extended to specifiers in I/O
>statements, ALLOCATE, DEALLOCATE, LOCK, ....  The easiest way to do so
>is to change the nomenclature for those specifiers from "appear" to
>"present".  This would have the additional salubrious effect of allowing
>optional arguments to specify their values.

Proposing to allow absent optional arguments as i/o specifiers has nothing to do 
with proposal 13.  It is a new proposal.

Given that i/o specifiers are few in number there is also no great motivation, 
though I agree that it would be more convenient... but I think it will only be 
useful in a vanishingly small number of cases; I can count the number of times I 
have seen IF (PRESENT(...)) THEN around alternative i/o statements, except for 
UNIT=* vs UNIT=N where this would not help anyway, on the fingers of one foot.

>Proposal 17 deals with allowing a rank-1 extent-R explicit-shape array
>with constant bounds to specify the bounds of a rank-R array in a
>specification statement.  This should be extended to include the bounds
>in an ALLOCATE statement.

This is a plausible extension of proposal 17.

(I will note that if the intent is to copy the bounds of another array of the 
same type and type parameters, Fortran 2008 already provides that functionality 
with the MOLD= specifier.  But there is no help for copying the bounds of 
another array of different type.)

Cheers,
-- 
................................Malcolm Cohen, Nihon NAG, Tokyo.