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From: Graham Perkins <gperkins@dmu.ac.uk>
Subject: Re: Software landmines (loops)
Date: 1998/10/05
Message-ID: <36188B41.72F9@dmu.ac.uk>#1/1
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Organization: De Montfort University Milton Keynes
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Date: 1998-10-05T00:00:00+00:00
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Robert C. Martin wrote:
> >> >loop
> >> >    ... stuff
> >> >    exit when ;
> >> >    ... stuff
> >> >end loop;
> ...
> The question that the post was addressing had to do with the definition of
> structured programming.  A mid exit loop does not fall within the bounds
> defined by structured programming because the loop body does not then have a
> single entry and a single exit.

I beg to differ.

The construct as a whole has single entry and exit points.  So I
think we could be entitled to regard it as a structured programming
construct.  Try slicing a CASE flowchart across the middle .. you
get more than one flow line crossing the cut!

Crucially, other parts of the program may not transfer control
to any intermediate point between LOOP-EXIT, nor gain control
from any such point.

----------------------------------------------------------------
Graham Perkins, De Montfort University, Milton Keynes
http://www.mk.dmu.ac.uk/~gperkins/