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: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public From: doylep@ecf.toronto.edu (Patrick Doyle) Subject: Re: Software landmines (loops) Date: 1998/09/06 Message-ID: #1/1 X-Deja-AN: 388471997 X-Nntp-Posting-Host: spark23.ecf Sender: news@ecf.toronto.edu (News Administrator) References: <6ssnp6$hv3$1@hirame.wwa.com> <35F20EA6.A0F7EFB8@s054.aone.net.au> <35F246E3.4424EF94@earthlink.net> Organization: University of Toronto, Engineering Computing Facility Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-09-06T00:00:00+00:00 List-Id: In article <35F246E3.4424EF94@earthlink.net>, Charles Hixson wrote: > >Now, I obviously haven't checked these with a compiler, but baring typos >I think that is is obvious that these pieces of code are all isomorphic, >so it seems TO ME unreasonable to claim that some of them are structured >and others of them aren't. > >I would like to hear about why others would find it reasonable. Dijkstra's structures are Turing equivalent, given a basic block at least as powerful as assignment. Thus, saying that a program is structured because a structured program can be transformed into it makes every conceivable program structured. So, unless we want to dilute the term to meaninglessness, I think we ought to disallow such transformations. Remember, structured programming is about the relationship between the text of a program and its dynamic behaviour. Thus, one can't neglect the text as you have done, and claim that transformations lead to equivalent programs, any more than you could alter the dynamic behaviour and consider it equivalent. -PD -- -- Patrick Doyle doylep@ecf.toronto.edu