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From: "John G. Volan" <johnvolan@sprintmail.com>
Subject: Re: Software landmines (loops)
Date: 1998/09/03
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Date: 1998-09-03T00:00:00+00:00
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Charles Hixson wrote:
> 
> In order for that to be an equivalently obvious form one would need to
> adopt an indentation convention that caused the exit test to stand-out
> as well as the top and the bottom of the loop do. 

Sure, why not?  See my post on another branch of this thread (gads, such
metaphor mixing!), describing a possible Eiffel extension that would
satisfy your criterion ("Mid-Loop 'Until' Proposal").

> Probably not hard,
> especially with colored-syntax editors (environments?), but not a
> current standard. (Well, at least not one that I know.)
> 
> Patrick Doyle wrote:
> ...
> > How would you feel about a loop...exit_when...end_loop structure?
> > It has only one exit point.  You could still add something to
> > the end of every iteration by putting it before the exit_when.
> >
> > This seems pretty safe to me.  Do you see any reason this would
> > be less manageable than a top- or bottom-exit loop?

I think the key question is whether one can devise a reasonable
semantics for such a construct such that important principles like
Design By Contract are upheld.  (Again, cf. my "Mid-Loop 'Until'
Proposal" post.)

-- 
indexing
   description: "Signatures for John G. Volan"
   self_plug: "Ex Ada guru", "Java 1.1 Certified", "Eiffelist wannabe"
   two_cents: "Java would be even cooler with Eiffel's assertions/DBC, %
              %generics, true MI, feature adaptation, selective export, %
              %uniform access, expanded types, etc., etc..."
class JOHN_VOLAN_SIGNATURE inherit SIGNATURE invariant
   disclaimer: not (opinion implies employer.opinion)
end -- class JOHN_VOLAN_SIGNATURE