[J3] [EXTERNAL] an amusing mistake

Tue Aug 4 21:30:25 EDT 2020

I agree with Robert. Deleting it just sweeps the issue under the rug – it does not help anyone; not compiler writers, not users, not people trying to work out what was and was not allowed.

The fix is not terribly difficult – on the face of it, inserting “immediately before the entity-decl-list” before “in the” is sufficient.

Robert, could you write this up as an interp please? It will be F18/021.

Cheers,

-- 

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

From: J3 <j3-bounces at mailman.j3-fortran.org> On Behalf Of Robert Corbett via J3
Sent: Wednesday, August 5, 2020 3:29 AM
To: General J3 interest list <j3 at mailman.j3-fortran.org>
Cc: Robert Corbett <rpcorbett at att.net>
Subject: Re: [J3] [EXTERNAL] an amusing mistake

The optional comma was present in FORTRAN 77,

which is as far back as the CHARACTER data type

goes.  The constraint was added in Fortran 90,

when the form and function of declaration

statements were greatly expanded. In Fortran 90

and Fortran 95, the constraint was correct,

because the double-colon separator could not

appear in a expression.  The syntax for array

constructors was extended in Fortran 2003 to

include an optional double-colon separator.

The constraint should have been modified in

Fortran 2003, or a different syntax should have

been chosen for array constructors.

I am surprised I did not notice the mistake

before.  I studied the Fortran 2003 standard

very closely when I was still working.

Deleting the optional comma would make lots of

existing codes nonstandard.  I would rather not

do that.  I am slightly less opposed to doing

it now that I am retired and do not have to

field complaints from irate users.

Bob Corbett

On Tuesday, August 4, 2020, 9:21:36 AM PDT, Clune, Thomas L. (GSFC-6101) via J3 <j3 at mailman.j3-fortran.org <mailto:j3 at mailman.j3-fortran.org> > wrote: 

Ditto. 

On Aug 4, 2020, at 11:13 AM, Dan Nagle via J3 <j3 at mailman.j3-fortran.org <mailto:j3 at mailman.j3-fortran.org> > wrote:

Hi,

On Aug 4, 2020, at 09:10 , Bill Long via J3 <j3 at mailman.j3-fortran.org <mailto:j3 at mailman.j3-fortran.org> > wrote:

Perhaps a more reasonable solution would be to just move the optional comma to the Deleted List. (Hence deleting the constraint). 

I can agree.

--

Cheers!
Dan Nagle

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