[J3] [EXTERNAL] Re: USE statement – wish: permit specifying additionally the access-spec

[Robert Corbett]

My first thought was that C815
prohibits this case.  If the attributes
PRIVATE and PUBLIC are both
regarded as the accessibility
attribute, it is prohibited.  If not,
there seems to be a missing
restriction in the existing text of
the standard.

Bob Corbett

> On Nov 15, 2019, at 3:38 PM, Van Snyder via J3 <j3 at mailman.j3-fortran.org> wrote:
> 
>> On Fri, 2019-11-15 at 23:04 +0000, Bill Long via J3 wrote:
>> While I'm not part of the Data subgroup, I’m pretty sure that the
>> design for this feature was not an oversight.  Rather, it likely had
>> to do with the fact that public and private declarations are limited
>> to being only in a module, whereas USE statements (often) appear
>> outside modules. Sure, you could add in a constraint that the
>> access-spec cannot be specified in a USE statement that is outside a
>> module, but that is just one extra complication that is not needed
>> with the current design. 
>> 
>> That said, we already permit redundant ways to specify public and
>> private for many other situations. So I would not be opposed to this
>> idea.  Some comment from /Data would be informative.
> 
> Another reason not to put an access-spec on a USE statement is that a
> scoping unit can have more than one USE statement for the same module.
> What is the effect of
> 
>  use, private :: A
>  use, public :: A
> 
> 
>> 
>> Cheers,
>> Bill
>> 
>> 
>> 
>>> On Nov 15, 2019, at 3:02 PM, Vipul Parekh via J3 <j3 at mailman.j3-fortran.org> wrote:
>>> 
>>> On Fri, Nov 15, 2019 at 11:32 AM Tobias Burnus via J3
>>> <j3 at mailman.j3-fortran.org> wrote:
>>>> ..
>>>> I still believe that a use-stmt with access-spec is more readable than
>>>> use-stmt + access-stmt, but I agree that the functionality is already
>>>> covered. Hence, I think one should still (re)consider it – but with low
>>>> priority.
>>>> ..
>>> 
>>> Tobias makes a good point.
>>> 
>>> Is it possible to know whether there was a reason besides an oversight
>>> as to why access-spec with the USE statement was not introduced in
>>> Fortran 2018 itself when the deficiency with the default accessibility
>>> for entities accessed from a module was addressed?
>>> 
>>> If this is an oversight with Fortran 2018, then how can one exhort J3
>>> but importantly WG5 to include this and other such "Features that
>>> address deficiencies and discrepancies" on the Fortran 202X work-list?
>>> 
>>> Thanks,
>>> Vipul Parekh
>> 
>> Bill Long                                                                       longb at cray.com
>> Principal Engineer, Fortran Technical Support &   voice:  651-605-9024
>> Bioinformatics Software Development                      fax:  651-605-9143
>> Cray, a Hewlett Packard Enterprise company/ 2131 Lindau Lane/  Suite 1000/  Bloomington, MN  55425
>> 
>> 
>> 
> 
>