From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,9a0ff0bffdf63657 X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,9a0ff0bffdf63657 X-Google-Attributes: gidf43e6,public X-Google-Thread: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public From: "Robert C. Martin" Subject: Re: Software landmines (loops) Date: 1998/10/03 Message-ID: <6v4d5l$blb$1@hirame.wwa.com>#1/1 X-Deja-AN: 397280584 References: <6qfhri$gs7$1@nnrp1.dejanews.com> <35cb8058.645630787@news.ne.mediaone.net> <902934874.2099.0.nnrp-10.c246a717@news.demon.co.uk> <6r1glm$bvh$1@nnrp1.dejanews.com> <6r9f8h$jtm$1@nnrp1.dejanews.com> <6renh8$ga7$1@nnrp1.dejanews.com> <6rf59b$2ud$1@nnrp1.dejanews.com> <6rfra4$rul$1@nnrp1.dejanews.com> <35DBDD24.D003404D@calfp.co.uk> <6sbuod$fra$1@hirame.wwa.com> <35f51e53.48044143@news.erols.com> <6sdiav$e0g$1@hirame.wwa.com> <6sfcft$70p$1@hirame.wwa.com> <1dg8p3r.vfredh1aou58iN@n207167116191.inetworld.net> <6v2nr9$t8l$1@hirame.wwa.com> <6v39i0$fte$1@winter.news.erols.com> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Organization: Object Mentor Inc. Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-10-03T00:00:00+00:00 List-Id: John I. Moore, Jr. <70672.1744@compuserve.com> wrote in message <6v39i0$fte$1@winter.news.erols.com>... >Robert C. Martin wrote in message <6v2nr9$t8l$1@hirame.wwa.com>... >>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'm sorry, Martin. I usually agree with your posts, but I will have to >object to this one. Whose definition are you using for structured >programming? Some of the earliest articles and books on structured >programming were written by Harlan Mills of IBM, and he always >defined a loop with a middle exit as an integral part of structured >programming. He called it a do-while-do loop. Yes, Mills did make this definition. However, I am referring to the work of Dijkstra in the late 60's and early 70's. Dijkstra was very clear about the notion of single entry and single exit within the body of a loop. I believe that Mills' do-while-do loop is an unauthorized addition to Dijkstra's work. Robert C. Martin | Design Consulting | Training courses offered: Object Mentor | rmartin@oma.com | Object Oriented Design 14619 N Somerset Cr | Tel: (800) 338-6716 | C++ Green Oaks IL 60048 | Fax: (847) 918-1023 | http://www.oma.com