do ... while loop

[Cameron Laird]

In article <000701bf17bf$ee71efe0$3e2d153f at tim>,
Tim Peters <tim_one at email.msn.com> wrote:
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>[Tim]
>> Those are never necessary, although it's amazing how often
>> people fall into believing they are.  The usual Python idiom ...
>
>[Cameron Laird]
>> It amazes me less than you.
>
>Are you picking a fight again <wink>?
Just reporting, as usual.  If I were to pick
a fight, 'twould probably be over the styl-
istic nihilism (or is it solipsism?  I always
have trouble with those field identifications)
you express nearby.  'You really believe
coding is so Expressionist?
>
>> Surely you remember the pedagogic fashion--is it still in bloom?--of
>> preferring "single-exit" control structures.
>
>It's alive and well, at least in Eiffel.  No "early exit" loops there!  If
>there's only one exit, the conjunction of the sole exit condition and the
>loop invariant must establish the loop postcondition, and that makes the
>proof framework as simple as possible.  That's a Great Good, so far as it
>goes.  Which is, alas, approximately nowhere:  the day serious reasoning
>about programs becomes widespread is the day most programmers abandon their
>craft to resume drug trafficking <wink>.
In fact, I'd argue this one, too.

Roughly, I've always assumed that, given
sufficient motivation and time, I could
work up a program-proving model which en-
compasses multiple-exit constructs, and
in fact demonstrates their relative de-
sirability when compared to the
multiple-artificial-boolean alternative.
I recognize that I must label this belief
purely speculative.  Has the academic
community truly not pushed this frontier
yet?  *That* surprises me.
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>Well, they will lose points, and they should.  But they also gain points for
>not ending up with a single exit condition choked with six artificial
>Boolean vrbls -- trading control complexity for data complexity may fool the
>automated complexity-checker, but the code is still a mess.  Let's see ...
>there are 856 gotos in Python's source code -- Guido must agree <wink>.
!  Fascinating.  You know what a sucker I am
for anything like measurement.
>(Odd!  Before counting, I would have sworn there were only a handful ...
>hmm, over 216 in almodule.c alone ... it's a *very* lumpy distribution.)
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>of anything changing here in Python1 is zero.  The only thing that ever got
>close to having a fighting chance (largely thanks to introducing no new
>keywords) was the "and while" statement; and that committed hypergeneralized
>suicide when it got expanded to the truly eccentric "and if" stmt.  This is
>why Guido so rarely has to squash a suggestion <0.5 wink>.
>
>leave-'em-alone-and-they-inflate-themselves-to-absurdity-ly y'rs  - tim
Is *that* what happens to parents?  Should the
stakeholders always toss out the original founders
and bring in seasoned operations people after grad-
uation from startup-hood (presumably around age
three, when they're making their own friends)?
-- 

Cameron Laird           http://starbase.neosoft.com/~claird/home.html
claird at NeoSoft.com      +1 281 996 8546 FAX