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: 1108a1,9a0ff0bffdf63657 X-Google-Attributes: gid1108a1,public X-Google-Thread: f43e6,9a0ff0bffdf63657 X-Google-Attributes: gidf43e6,public X-Google-Thread: fac41,9a0ff0bffdf63657 X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,4b06f8f15f01a568 X-Google-Attributes: gid103376,public From: doylep@ecf.toronto.edu (Patrick Doyle) Subject: Re: Software landmines (loops) Date: 1998/09/03 Message-ID: #1/1 X-Deja-AN: 387377541 X-Nntp-Posting-Host: spark19.ecf Sender: news@ecf.toronto.edu (News Administrator) References: <35f51e53.48044143@ <904556531. Organization: University of Toronto, Engineering Computing Facility Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.lang.ada Date: 1998-09-03T00:00:00+00:00 List-Id: In article , Matthew Heaney wrote: > >My argument concerns the complexity of the decision table for the loop >predicate. Adding a flag doubles the number of states. I don't get this. Who enumerates the states? Who really finds this necessary to understand a loop? The termination condition is always the disjunction of the normal termination condition and the flags. A disjunction is a very simple, straightforward logical operation, and I believe that the effort in comprehending a disjunction is O(n), not O(2^n), in the number of terms. Look at this: from x := 1 until x > maximum or error_detected or user_interruption or list_is_sorted loop ... end This has four conditions. Do you really think it's 16 times harder to understand than just "until x > maximum"? I'd believe it's 4 times harder. -PD -- -- Patrick Doyle doylep@ecf.toronto.edu