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Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct

Date 2012-03-17 21:59 -0500
From Evan Driscoll <driscoll@cs.wisc.edu>
Subject Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct
References <gR09r.22645$I33.16090@uutiset.elisa.fi>
Newsgroups comp.lang.python
Message-ID <mailman.773.1332040943.3037.python-list@python.org> (permalink)

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On 3/17/2012 9:03, Antti J Ylikoski wrote:
> 
> In his legendary book series The Art of Computer Programming,
> Professor Donald E. Knuth presents many of his algorithms in the form
> that they have been divided in several individual phases, with
> instructions to GOTO to another phase interspersed in the text of the
> individual phases.
> 
> 
> A1.  (Do the work of Phase A1.)  If <zap> then go to Phase A5,
> otherwise continue.
> 
> A2.  (Do some work.) If <zorp> go to Phase A4.
> 
> A3.  (Some more work.)
> 
> A4.  (Do something.)  If <condition ZZZ> go to Phase A1.
> 
> A5.  (Something more).  If <foobar> then go to Phase A2, otherwise
> end.

Clearly you just need the goto module (http://entrian.com/goto/):

  from goto import goto, label

  label .A1
  # do work of phase A1
  if <zap>: goto .A5

  label .A2
  # do some work
  if <zorp>: goto .A4

  # do some more work

  label .A4
  # do something
  if <condition zzz>: goto .A1

  label .A5
  # something more
  if <foobar>: goto .A2

Clearly the best solution of all.

(Note: do not actually do this.)

Evan

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Thread

Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Antti J Ylikoski <antti.ylikoski@tkk.fi> - 2012-03-17 16:03 +0200
  Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Mel Wilson <mwilson@the-wire.com> - 2012-03-17 10:39 -0400
  Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-17 15:45 +0100
    Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Michael Torrie <torriem@gmail.com> - 2012-03-17 09:01 -0600
      Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-17 16:12 +0100
        Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Michael Torrie <torriem@gmail.com> - 2012-03-17 09:53 -0600
          Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-17 18:55 +0100
            Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Michael Torrie <torriem@gmail.com> - 2012-03-17 17:28 -0600
              Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-18 01:54 +0000
                Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-18 11:03 +0000
              Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-19 02:02 +0100
                Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-03-19 01:02 -0400
                Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-19 11:24 +0100
  Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Roy Smith <roy@panix.com> - 2012-03-17 11:47 -0400
    Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Antti J Ylikoski <antti.ylikoski@tkk.fi> - 2012-03-17 18:31 +0200
      Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct John Nagle <nagle@animats.com> - 2012-03-17 11:44 -0700
  Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Evan Driscoll <driscoll@cs.wisc.edu> - 2012-03-17 21:59 -0500
  Re: Programming D. E. Knuth in Python with the Deterministic Finite Automaton construct Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-18 11:08 +0000

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