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From: Tim Ottinger <ottinger@oma.com>
Subject: Re: Software landmines (loops)
Date: 1998/09/01
Message-ID: <35EBF28B.FD4F38EC@oma.com>#1/1
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Date: 1998-09-01T00:00:00+00:00
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Robert Martin wrote:
> The the invariants of the loop body are different depending on whether the
> iteration is the last or not.  Also, a programmer must be aware that the
> last statement in the loop body will not be executed on the last iteration.

Of course, the example is "in the small". Very small things tend to be
fairly easy to understand. To really appreciate the rules, you have to
have a moderately complex loop with if/then/else or switch/case in the
middle, preferably nested three levels deep or more ;-)

I personally like checking rules at the front of a function, and
returning
early if conditions aren't met... at least for checking invariants.
Assert 
is better if you want to abort when the condition isn't met.

But the question I have is what happens when we have exceptions. Those
are
most certainly an early exit and may occur at unpredicted times. How
do
the rules for single entry/exit apply in an exception-supporting
language?


Tim