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From: sakkinen@jyu.fi (Markku Sakkinen)
Newsgroups: comp.lang.misc
Subject: Re: Run-time Type Errors in Smalltalk
Message-ID: <1991Apr16.121135.1761@jyu.fi>
Date: 16 Apr 91 12:11:35 GMT
References: <1917@optima.cs.arizona.edu>
Reply-To: sakkinen@jytko.jyu.fi (Markku Sakkinen)
Organization: University of Jyvaskyla, Finland
Lines: 37

In article <1917@optima.cs.arizona.edu> gudeman@cs.arizona.edu (David Gudeman) writes:
>In article  <1991Apr15.065146.16680@tkou02.enet.dec.com> Norman Diamond writes:
>]In article <4243.2805b94a@iccgcc.decnet.ab.com> klimas@iccgcc.decnet.ab.com writes:
>]>	Some info that I picked up from a company doing a lot of big
>]>	project work with C++ (i.e. strong type checking language) was
>]>	that postmortems on their project revealed only 10% of their
>]>	errors were captured by strong type checking.
>]...
>]In any other field of engineering, a 10% increase in safety would always
>]be applied.  To reject it would be grounds for lawsuits, at least.
>
>How do you get a 10% increase in safety from the above?  If they
>hadn't caught those errors by static typing they would have caught
>them by testing -- the same way the found the other 90% of the errors.

It is very wishful thinking that all errors would be found by testing.
"Testing can only prove the presence of errors, never their absence."
But I think this quote is from Hoare, whom you probably would not
believe anyway.

>This logic error combined with the strident tone of the article
>suggests that your convictions are affecting your thinking.
>--
>					David Gudeman

Look who's talking!  When you have a difference of opinion with Diamond,
you call his opinion a "logic error" and then accuse him of "strident tone".
BTW, it would be a queer conviction indeed that wouldn't affect a person's
thinking at all.

Markku Sakkinen
Department of Computer Science and Information Systems
University of Jyvaskyla (a's with umlauts)
PL 35
SF-40351 Jyvaskyla (umlauts again)
Finland
          SAKKINEN@FINJYU.bitnet (alternative network address)