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: f43e6,9a0ff0bffdf63657 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public From: Charles Hixson Subject: Re: Software landmines (loops) Date: 1998/09/06 Message-ID: <35F2F058.89D67D24@earthlink.net>#1/1 X-Deja-AN: 388493295 Content-Transfer-Encoding: 7bit References: <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$1@hirame.wwa.com> <904556531.666222@miso.it.uq.edu.au> <6sgror$je8$3@news.indigo.ie> <6sh3qn$9p2$1@hirame.wwa.com> <35ece7ee.1489912@news.erols.com> <35ED7082.1889@hfl.tc.faa.gov> <8SeH1.542$495.132579351@newsreader.digex.net> <35EDAC92.538A@hfl.tc.faa.gov> <6sknla$7so$1@hirame.wwa.com> X-Posted-Path-Was: not-for-mail Content-Type: text/plain; charset=us-ascii X-ELN-Date: Sun Sep 6 13:25:14 1998 Organization: Mandala Fluteworks Mime-Version: 1.0 Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-09-06T00:00:00+00:00 List-Id: I feel it important to call attention to the fact that the returns are occuring BEFORE and non-temporary effects happen. There are different things that multiple returns can be. I feel this form to be BENEFICIAL, and analogous to the pre-conditions of Eiffel. OTOH, a return from within the body of "now do the real work" would be an ill-structured added return. The problem is that we are calling different program structures by the same name. And our languages don't support the early-return with a different syntax, so it is very easy to confuse them. Robert Martin wrote: > > Robert Oliver wrote in message <35EDAC92.538A@hfl.tc.faa.gov>... > > > > >I am not arguing against all use of multiple returns in a procedure or > >function. I often write a function like this: > > > >void AFunction(...) > >{ > > if (SomeCondition) return; > > if (AnotherCondition) return; > > if (AThirdCondition) return; > > > > // now do the real work... > > > > return; > >} > > > >I think this makes sense when AFunction is called from many places and > >the > >conditions need to be tested each time. I can look at the beginning of > >the > >function and know that there will be nothing done in these three > >circumstances. > >It's not without danger as RCM has pointed out, but I often choose to > >live > >with the risk. > > *Deciding* to live with the risk is perfectly legitimate. There is no way > to eliminate all risk. Thus we must choose the risks we live with. But it > is important that the risks be understood. > > > >Of course, it could also be written as: > > > >void AFunction(...) > >{ > > if not (SomeCondition) and > > not (AnotherCondition) and > > not (AThirdCondition) then > > > > // now do the real work... > > > > endif > > return; > >} > > Which is usually how I would choose to write it. (Active voice instead of > passive voice. ;^) > > 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 > > "One of the great commandments of science is: > 'Mistrust arguments from authority.'" -- Carl Sagan