--- Comment #12 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Fri, Feb 09, 2018 at 09:15:00PM +0000, mecej4 at outlook dot com wrote:
> > I cannot find a prohibition in F2018 standard.
> > AFAICT, gfortran always supported keywords, and
> > I've developed a patch to retain that behavior.
> I cannot find an explicit prohibition, either, but please consider these
> related statements from F2003:
I found where the prohibition occurs in F95, F2003, and F2018.
If you want to get a headache, read F2018, 15.5. It's a little
convoluted to chase down all the terms because of the wonderful
OOP language, but one has
R1520 function-reference is procedure-designator ( [ actual-arg-spec-list ] )
C1523 (R1520) The procedure-designator shall designate a function.
R1523 actual-arg-spec is [ keyword = ] actual-arg
C1530 (R1523) The 'keyword =' shall not appear if the interface of
the procedure is implicit.
The first thing to chase down is 'procedure' in C1530 means 'function
or subroutine'. Then one needs to chase down that 'function' means
'function (in a Fortran subprogram sense) or statement function.'