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=1.1 required=5.0 tests=BAYES_20,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,ef0074ec236ba6e3 X-Google-Attributes: gid109fba,public X-Google-Thread: 1014db,ef0074ec236ba6e3 X-Google-Attributes: gid1014db,public X-Google-Thread: 103376,b19fa62fdce575f9 X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,ef0074ec236ba6e3 X-Google-Attributes: gid1108a1,public X-Google-Thread: 108717,ef0074ec236ba6e3 X-Google-Attributes: gid108717,public X-Google-ArrivalTime: 1994-12-05 08:46:41 PST Path: bga.com!news.sprintlink.net!howland.reston.ans.net!gatech!hubcap.clemson.edu!hubcap!mjs From: mjs@hubcap.clemson.edu (M. J. Saltzman) Newsgroups: comp.lang.ada,comp.lang.c,comp.programming,comp.lang.c++,comp.object Subject: Re: Why don't large companies use Ada? Date: 5 Dec 94 16:11:18 GMT Organization: Clemson University Message-ID: References: <3aa7jo$7j@Starbase.NeoSoft.COM> <3bd06n$kbt@felix.seas.gwu.edu> <3bldlu$84r@gnat.cs.nyu.edu> <3bo402$23a@felix.seas.gwu.edu> <3bvc4k$1lla@watnews1.watson.ibm.com> NNTP-Posting-Host: hubcap.clemson.edu Xref: bga.com comp.lang.ada:8285 comp.lang.c:33416 comp.programming:5623 comp.lang.c++:39634 comp.object:9437 Date: 1994-12-05T16:11:18+00:00 List-Id: ncohen@watson.ibm.com (Norman H. Cohen) writes: >In article <3bo402$23a@felix.seas.gwu.edu>, mfeldman@seas.gwu.edu >(Michael Feldman) writes: >|> In general I agree, and find that subtypes give the needed range checks >|> without getting the programmer into type-compatibility stew, but there >|> are these persistent "urban myths" about Fortran codes whose mangled >|> dimension analysis sent space probes off the wrong way, etc. >The urban myth about the space probe is not concerned with strong typing >of data, but with what we could call strong typing of lexical elements! Right enough. On the other hand, in the late 80's there was a "Star Wars" test involving a mirror on the Space Shuttle and a laser on the ground. At test time, it turned out that the Shuttle was oriented with the mirror pointing *away* from the earth. I believe that the error was indeed traced to faulty dimensional analysis (a distance in feet passed to a module that expected miles, or something similar). -- Matthew Saltzman Clemson University Math Sciences mjs@clemson.edu