(j3.2006) IMPLICIT NONE in BLOCK

Robert Corbett rpcorbett
Fri Feb 23 03:32:55 EST 2018


If every BLOCK construct in an inclusive scope includes an IMPLICIT NONE statement, the problems I described in my e-mail last year cannot occur.? If there is a mix of BLOCK constructs that do and do not use IMPLICIT NONE, there can be problems.? I would like to include a copy of that e-mail, but I cannot find the e-mail archive.
Robert Corbett 

    On Friday, February 23, 2018 12:20 AM, Van Snyder <van.snyder at jpl.nasa.gov> wrote:
 

 On Fri, 2018-02-23 at 00:03 -0800, Robert Corbett wrote:
> If a user wants IMPLICIT NONE to be in effect within a BLOCK
> construct, he or she should put an IMPLICIT NONE statement in a
> non-BLOCK scoping unit containing the BLOCK construct.? Because it is
> good practice to always use IMPLICIT NONE, putting IMPLICIT NONE in
> one or more of the containing scoping units should not be too great a
> burden.

The situation that Vipul Parekh discussed, and that I repeated, involved
maintenance of a large antique legacy code.? It might not be
economically feasible to add IMPLICIT NONE at procedure scope and then
add explicit declarations for everything.? The primary reason for using
BLOCK constructs in this situation is to minimize labor cost.? Indeed,
the only reason for the existence of high-level programming languages is
to minimize labor cost.

So, to get back to the original question, rather than deflect discussion
of it toward new codes only, would it be feasible to allow IMPLICIT
NONE, and no other kind of IMPLICIT for the reasons we all understand,
in BLOCK constructs?? I don't see how it could affect existing codes.
The question boils down to the effect on processors and the standard.




   
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