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: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,9a0ff0bffdf63657 X-Google-Attributes: gidf43e6,public From: "Robert C. Martin" Subject: Re: Software landmines (loops) Date: 1998/10/05 Message-ID: <6vam60$ot0$1@hirame.wwa.com>#1/1 X-Deja-AN: 397921754 References: <6qfhri$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$1@winter.news.erols.com> <6v4d5l$blb$1@hirame.wwa.com> <6v5en9$d46$1@winter.news.erols.com> X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Organization: Object Mentor Inc. Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-10-05T00:00:00+00:00 List-Id: John I. Moore, Jr. <70672.1744@compuserve.com> wrote in message <6v5en9$d46 >2. Mills construct of do-while-do has a single entry and single exit, > as do all of the other structured programming constructs. Using > an Ada-like syntax, consider the following: > > loop > get x; > exit when x satisfies some condition; > process x; > end loop; > > I contend that this logic is natural, that the loop has only a > single entry and exit, and that it doesn't violate any of the > structured programming guidelines. Of course, one can rewrite > it by using a standard while-loop, just as one can rewrite any > repeat-until loop using a while-loop, but in order to do so you > must repeat some part of the logic outside of the loop. Ooops. Sorry, I was mistaking mid-exit loops for loops with extra exits in them. Yes, a pure mid-exit loop (e.g. Mills' do-while-do *is* compatible with structured programming. Sorry for the fuss. You were right and I was wrong. 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