From: Hugh Sasse <hgs@...>
Date: 2006-10-13T00:41:12+09:00
Subject: Re: Debugging in the large, modern practice?

On Thu, 12 Oct 2006, Eivind Eklund wrote:

> Invariant checks ("Design by Contract"), mostly.  Adding invariant
> checks to your system will often unearth weird cases - making them
> easily reproducable and making them fail early.

Yes, this is something I need to know more about.  In Programming Pearls
I've seen lots of mention of invariants, e.g. for loops,  but though 
I think I understood what was being said, I found that I didn't 'grok'
the statements deeply.  I think I need to understand more about how to 
think in this way.  Some of this is probably covered by "What could
I put in an assert statement that would always succeed (for this loop
or whatever", but I suspect the concept runs deeper.
> 
> Testing (which has already been mentioned) can handle some of the same
> niche, by removing coupling and allowing you to externally check for
> invariants being kept.  However, it is usually much easier to add
> invariant checks to a system than to add tests.
> 
> Eivind.
> 
> 

        Thank you,
        Hugh