[petsc-dev] Fortran source format

Satish Balay balay at mcs.anl.gov
Sat Jan 23 14:04:40 CST 2010

On Sat, 23 Jan 2010, Jed Brown wrote:

> On Sat, 23 Jan 2010 13:51:16 -0600 (CST), Satish Balay <balay at mcs.anl.gov> wrote:
> > Note 3.10 of the Fortran 2003 standard describes a way to write
> > Fortran include files so that they can be used with either free form
> > or fixed form source.
> Perfect.  The draft of the standard can be downloaded here (the real
> thing costs money).
>   http://j3-fortran.org/doc/2003_Committee_Draft/ISO_IEC_1539-1.pdf

Great! Page 46 had the 'note 3.10'

NOTE 3.10
In some circumstances, for example where source code is maintained in an INCLUDE file for use in programs whose
source form might be either fixed or free, observing the following rules allows the code to be used with either source
        (1)   Confine statement labels to character positions 1 to 5 and statements to character positions 7 to 72;
        (2)   Treat blanks as being significant;
        (3)   Use only the exclamation mark (!) to indicate a comment, but do not start the comment in character
              position 6;
        (4)   For continued statements, place an ampersand (&) in both character position 73 of a continued line
              and character position 6 of a continuing line.

I've assumed the ampersand (&) can be in any location after 72 - not just 73rd char. Oh well..


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