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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,b87849933931bc93 X-Google-Attributes: gidfac41,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public X-Google-Thread: 109fba,b87849933931bc93 X-Google-Attributes: gid109fba,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public X-Google-Thread: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public From: "Norman H. Cohen" Subject: Re: OO, C++, and something much better! Date: 1997/01/27 Message-ID: <32ED2DD3.76B4@watson.ibm.com>#1/1 X-Deja-AN: 212717477 references: <32DF458F.4D5C@concentric.net> <32DF94DC.6FF8@watson.ibm.com> <32DFD972.37E4@concentric.net> <32E4FC5B.242C@watson.ibm.com> <32E6862D.608B@parcplace.com> <32E788D4.4B91@watson.ibm.com> <32E8EB48.2C0C@parcplace.com> content-type: text/plain; charset=us-ascii organization: IBM Thomas J. Watson Research Center mime-version: 1.0 reply-to: ncohen@watson.ibm.com newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng x-mailer: Mozilla 3.0 (Win95; I) Date: 1997-01-27T00:00:00+00:00 List-Id: Eric Clayberg wrote: > If you say > that apps built with Ada are even more stable, then great. Do you have > any evidence that shows that deployed Ada apps are more stable in > practice than deployed Smalltalk apps? I have never seen anything beyond > supposition and guesses (usually offered up by folks who have never used > Smalltalk). No, I've such comparisons between Ada and C/C++ (see, for example http://sw-eng.falls-church.va.us/AdaIC/docs/reports/cada/cada_art.html, which shows the same programmers developing Ada code and C code, and producing the average Ada line for 60% of the cost of an average C line, with only 1/6 as many defects in the delivered code), but not between Ada and Smalltalk. I would certainly be interested in such comparisons. If there are any Smalltalk versus C comparisons, it would be interesting to observe whether the same factors are achieved (with the caveat that this is not as controlled an experiment as a direct comparison of Ada and Smalltalk code written by the same programmers). > Are you saying that Ada is incapable of propagating errors to the end > user? All errors are guaranteed to be fixed prior to deployment? That > would be remarkable. Of course I'm saying no such thing. I am saying that there is a large class of errors that (1) occur frequently in real programs and (2) could be caught at compile time in a language that allows many consistency properties to be encoded as type distinctions and enforces type distinctions. This class does not include all errors by any means, but it includes enough errors to make a huge difference in reliability. -- Norman H. Cohen mailto:ncohen@watson.ibm.com http://www.research.ibm.com/people/n/ncohen