[plt-scheme] debugging [mini rant]

From: Eli Barzilay (eli at barzilay.org)
Date: Wed Jul 29 12:14:09 EDT 2009

Sorry to contribute another post on this, but just to clarify:

On Jul 29, Robby Findler wrote:
> On Wed, Jul 29, 2009 at 7:50 AM, Mike Eggleston<mikeegg1 at mac.com> wrote:
> >
> > Not bogus for me. I perform this type of debugging often on
> > production systems. I like to know I have made no changes to a
> > system I'm trying to find the error in, that I've not introduced
> > another issue by changing the code to add printf()s (stdout or
> > file).

What I described had nothing to do with Scheme, it was a C++ project
on Windows.  But in general my point was that Robby's comment:

> No to belabor the obvious here, but debuggers change the behavior of
> your program (perhaps even more than printfs, depending on what
> you're doing).

is wrong in using "perhaps".  Debuggers (including the one that I used
and the one in PLT) always change code in a way that is much more
intense than adding some printfs.  So an argument in favor of a
debugger of adding some printouts because you want to avoid the
printouts from modifying your program is bogus as printouts are less
likely to do so.

          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                    http://barzilay.org/                   Maze is Life!

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