Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/5/84; site reed.UUCP
Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!whuxl!houxm!vax135!cornell!uw-beaver!tektronix!reed!alexis
From: alexis@reed.UUCP (Alexis Dimitriadis)
Newsgroups: net.lang.c
Subject: Re: C bites Dog!
Message-ID: <1835@reed.UUCP>
Date: Sun, 25-Aug-85 01:25:22 EDT
Article-I.D.: reed.1835
Posted: Sun Aug 25 01:25:22 1985
Date-Received: Tue, 27-Aug-85 06:47:09 EDT
References: <872@brl-tgr.ARPA>
Reply-To: alexis@reed.UUCP (Alexis Dimitriadis)
Organization: Reed College, Portland, Oregon
Lines: 70
Summary: 

> > > > 		if (sv > score);   <----- note extraneous semi-colon
> > > > 			score = sv;
> > ICK ICK ICK! I hate languages that do that. Ever considered using "cb" as a
> > debugging tool? I have an MS-DOS version if anyone wants it...
> [...]  What
> would you do, compare the output of `cb' with the original? Takes
> lots of time & can be visually overlooked.

  Here is an idea I've had on the back burner for while: How about a
program that checks the formatting of the source code for consistency?
  - Take a C beautifier.  
  - Modify the lexical analyzer so it passes the amount of indentation
    preceding the line each input statement is on.
  - Now for each statement, check the _relative_ indentation.  A normal
    statement should be indented exactly as far as the previous statement;
    the subordinate part of an "if" or a loop should be further indented,
    or be on the same line; lines that contain continuation of an expression
    can start anywhere, and do not affect the expected indent; etc.
  - If the input disagrees, give a diagnostic.

  This should catch things like
    if (tv.set == junk);
	turn(off);
or even
    while (cat == away)
	mice(dance);
	cheese--;
since the "while" should be aligned with the "cheese".  Of course,
it would be powerless with
    if (procter & gamble); chips++;
unless you put in a rule about multiple equal-level statements on the
same line, which would create problems with macro expansion, etc.

  Now I haven't started work on this yet, (first I finish my thesis),
but it seems it could be made to work consistently, and without a lot
of false alarms.  However, a friend who may know better disagrees.
Are there really impossible obstacles to the task?  I know the lexical
analyzer would have to keep track of the offset, and probably line
number, of every token, but that's no big deal.

  Could it cope with the thousands of indenting styles?  I think the
test is general anough to cope with anything.  Since there are so many
places braces can be, they could be just ingored.

  Is it a pipe dream? Has it been done before?  (If it has, it must be
a well kept secret!).  What should I watch out for? Whose code would
it gag on?  If you have the answers to any of this, (or even some good
questions), I would appreciate hearing from you.

  Finally, I apologize for the length of this, and please! none of the
above condones of condemns any particular style of indenting, the
subject has been trashed to death anyway.  I have kept the results of
the indenting style survey, I will mail them to anyone interested.

Thanks for your attention,
Alexis Dimitriadis 

  PS. I have lost the name of the person who conducted the survey.  If
you still have the "other style" answers, could you send me a list?
-- 
_______________________________________________
  As soon as I get a full time job, the opinions expressed above
will attach themselves to my employer, who will never be rid of
them again.

             alexis @ reed

                 ...teneron! \
...seismo!ihnp4! - tektronix! - reed.UUCP
     ...decvax! /