From mboxrd@z Thu Jan  1 00:00:00 1970
Mime-Version: 1.0 (Apple Message framework v619.2)
In-Reply-To: <Pine.GSO.4.58.0504012026300.14759@cps211.cps.cmich.edu>
References: <Pine.GSO.4.58.0504012026300.14759@cps211.cps.cmich.edu>
Content-Type: text/plain; charset=US-ASCII; format=flowed
Message-Id: <5ef017b602f99114e817ac37589aef3d@coraid.com>
Content-Transfer-Encoding: 7bit
From: Brantley Coile <brantley@coraid.com>
Subject: Re: [9fans] OT: programming style under Plan9??
Date: Fri,  1 Apr 2005 22:34:31 -0500
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Topicbox-Message-UUID: 30abb086-ead0-11e9-9d60-3106f5b1d025

Speaking as a semi old fart, some of the early structure of
programs into separate files was just to keep the file
small enough to compile quickly.  Dennis' pdp11 compiler
was a number of files that all essentially got cat'ed together.
Back when a MIP was a real MIP and you had only one,
having the source in small files really sped up compilation.
You could get a lot more work done in a given amount of time.
The first thing I noticed when I first saw the Plan 9 code in 1990
was how header definitions were combined into the same file.
This turned out to be a great win.

Of course, a more constructive answer would be to get a copy
of ``The Practice of Programming'' by Kerninghan and Pike.

I would make the remark that C doesn't have modules.  After
compiling the code type information is lost and you can link
to anything that will resolve a name.  For example I can treat
the name qsort(3) as an array of integers.  The loader will resolve
the name qsort and the code in main will just do what I told it to.
This in in contrast to Wirth's Oberon that does type checking
at compile, link and runtimes.


#include <stdio.h>

extern int qsort[10];

void
main(void)
{
         int i;

         for (i = 0; i < 10; i++)
                 printf("%08x\n", qsort[i]);
         exit(0);
}
   Brantley


On Apr 1, 2005, at 8:34 PM, I RATTAN wrote:

> I have observed that that the Plan9 C-code generally
> consists fo ALL modules of a program are in the same file.
> Is it deliberate or a matter of style? It does make life
> easier in terms of include files but seems a bit little off
> key in context that C supports separate compilation of modules
> and hence, each module could be in a file of its own! I was accused
> of being University type in comp.lang.python for asking how
> keep each modules in a separate file  and make the program
> work correctly.
>
> Thanks in advance.
> -ishwar
>