Re: [open-cobol-list] Fixed vs Free Format

[Brian Tiffin]

On Thu, 17 Nov 2011 16:12:07 -0500, Andrew Pennebaker  
<address@hidden> wrote:

> Honest questions from a newbie:
>
>    - Does free format allow arbitrarily indented code like Ruby, or
>    consistent indentation like Python, or farthest indentation like  
> Haskell?

Arbitrary.

>    - Does free format allow extra whitespace?

Yep.  By standard, FIXED form is converted to FREE form during  
preprocessing.  Try running various sources through cobc -E to see.  If I  
remember correctly, we are only limited by an internal 2048 character line  
buffer.

> Can we subsume fixed format into free and have the compiler
> *encourage*people to use free but never complain when we code in
> fixed?

I would say no to that one.  From the Draft standard

  6
  Reference format
  6.1
  General
  Reference format specifies the conventions for writing COBOL source text  
and library text. COBOL provides two
  reference formats: free-form reference format and fixed-form reference  
format. The two types of reference format
  may be mixed within and between source text and library text by use of  
SOURCE FORMAT compiler directives. The
  default reference format of a compilation group is fixed-form.

By standard, default format is fixed-form. And I would NOT encourage  
people to use free form.  Personal preference is always allowed but spec  
calls for FIXED default.

If you'd like a compiler for personal use, look to cobc/cobc.h and swap  
the 0 and 1 on CB_FORMAT_FREE and CB_FORMAT_FIXED.  For me, making changes  
to the sources and building a personal compiler is wicked cool and feels  
manly.  ;)

In reality, it might be better to just

$ alias cobc='cobc -free'

But if I had to maintain any code I'd still like to see   OCOBOL >>SOURCE  
FORMAT IS FREE  on line 1 if that was the intent.
(the OCOBOL is just a personal sequence number preference of mine).  And  
line one should ALWAYS be coded to FIXED form rules in my opinion.  A few  
simple tricks and FIXED form sources will compile -free.

> Whitespace is a good way to visually separate components of a larger
> system. Since code proceeds line by line, vertical whitespace is a  
> powerful
> way to make code more readable. Horizontal whitespace in the form of tabs
> and spaces helps to indicate nested blocks of code. I agree that  
> whitespace
> makes code much more readable.
>
> However, requiring seven spaces before each line of code is just silly.

I'll disagree.  :)  I might be biased, but the FIXED form samples in the  
OC FAQ seem pretty reasonable to me, and I'd say readable.  Even the  
single sentence procedure division in ocdoc.cob  
http://opencobol.add1tocobol.com/#what-is-ocdoc seems, to me, to be  
quickly grokable.


> It
> adds no whitespace; it just shifts all code over. You might as well drag  
> a
> text editor window over to the right; it's aesthetically identical and  
> adds
> just as much "readability". I realize the historicity of the extra
> characters, but tradition /= good practice. We have text editors to show
> line numbers, so we don't need that column any more.

Perhaps not need, but it's there and a LOT of existent shops that use the  
sequence number area for sanity control over large masses of source code.

> There is indeed the potential for breaking backwards compatibility, and  
> for
> alienation of people who prefer the spurious spaces. But computers exist  
> to
> automate; there's no technological reason that OpenCobol can't read a  
> .cob
> file, decide for itself which format is being used, fixed or free, and  
> run
> with it. One solution is to read the first line: If there are six spaces
> and a star, consider the file to be in fixed format. If there are no
> spaces, consider the file to be in free format. Or you could go so far as
> statistical analysis to determine which format is being used more often  
> in
> a file, and inform the coder of the exceptions. There are myriad ways to
> make fixed and free coders happy, all without requiring flags or setting
> defaults.

Harder than it may look.  Peruse cobc/pplex.l for some hints on how weird  
the guessing game would be.

I'm a FIXED fellow by nature, but code to both forms.  I'm already super  
happy with the flexibility in OpenCOBOL.

> Cheers,
>
> Andrew Pennebaker
> www.yellosoft.us

Cheers,
Brian

> On Thu, Nov 17, 2011 at 3:48 PM, john Culleton  
> <address@hidden>wrote:
>
> > On Thu, 17 Nov 2011 15:42:24 -0500
> > Andrew Pennebaker <address@hidden> wrote:
> >
> > > Can -free be the default in future versions?
> > >
> > > Cheers,
> > >
> > > Andrew Pennebaker
> > > www.yellosoft.
> > I prefer fixed as the default. COBOL is designed to be readable.
> > The fixed format aids in that.
> >
> > --
> > John Culleton
> > Free list of books for self-publishers:
> > http://wexfordpress.net/shortlist.html
> >
> > "Create Book Covers with Scribus"
> > http://www.booklocker.com/books/4055.html
> >
> >
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