Re: Relevant article
Daniel Bolgheroni wrote on Thu, Sep 10, 2009 at 05:09:09PM +: since Nick Holland touched on the DESIGN aspect in his e-mail regarding supporting OpenBSD, I think this article pretty much reflects the reality here. http://www.osnews.com/story/22135/The_Problem_with_Design_and_Implementation Just think it's worth reading. Hardly; it's wrong because the author considers trivial tasks only. By definition, for trivial tasks, specification and implementation roughly agree in size and content, and no design is involved. For a very small, yet non-trivial example, look at: Specification: * double sin(double x) - the sine function, x in radians * sin(Inf or NaN) is NaN Implementation: /usr/src/lib/libm/src/k_sin.c and s_sin.c Even if i add a proper mathematical definition to the specs, e.g. e^z := sum(k in N0) z^k/k!, z in C; sin(x) := Im(e^ix), x in R, the specification is still short and easy to understand, the implementation is tricky, and both are not trivial to convert to each other. I guess libcrypto contains more scary stuff. In any case, if that's what you were driving at, OpenBSD quality is not caused by confusing design and implementation, but by keeping the first simple and functional and the second correct and robust.
Relevant article
Hi, since Nick Holland touched on the DESIGN aspect in his e-mail regarding supporting OpenBSD, I think this article pretty much reflects the reality here. http://www.osnews.com/story/22135/The_Problem_with_Design_and_Implementation Just think it's worth reading. Teers, -- Daniel Bolgheroni FEI - Faculdade de Engenharia Industrial http://www.dbolgheroni.eng.br/mykey ASCII ribbon campaign ( ) against HTML e-mail X / \
Re: Relevant article
On Thu, Sep 10, 2009 at 17:09 +, Daniel Bolgheroni wrote: Hi, since Nick Holland touched on the DESIGN aspect in his e-mail regarding supporting OpenBSD, I think this article pretty much reflects the reality here. http://www.osnews.com/story/22135/The_Problem_with_Design_and_Implementation Just think it's worth reading. What came to my mind while reading this article is an almost 30yo tale from the times of my first encounter with Unix release 6 on PDP11. I was studying CS at TU Berlin then and we had a OS Prof Siggi Schindler (he's the reason why I use the 'y') who also led a course on the ISO 7 layer model with practical applications. AFAIR everything essentially boiled down to having a *precise specification language*. If you have such a language the only thing left to do is building a machine that accepts this language as it's programming language. In this sense implementing a specification in any existing programming language is equivalent to implementing a subset of said machine on top of an existing one. Siggy -- O ascii ribbon campaign - stop html mail - www.asciiribbon.org+ |36 days until|bsb-at-psycho-dot-informationsanarchistik-dot-de| |www.Ubucon.de|or:bsb-at-psycho-dot-i21k-dot-de| +--- ceterum censeo javascriptum esse restrictam + [demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc]
Re: Relevant article
On Thu, Sep 10, 2009 at 23:15 +0200, Bernd Siggy Brentrup wrote: [demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc] Oops, in general I gpg-sign my mails with a detached signature but if it's this list's policy not to do so I'll refrain from it. Siggy -- O ascii ribbon campaign - stop html mail - www.asciiribbon.org+ |36 days until|bsb-at-psycho-dot-informationsanarchistik-dot-de| |www.Ubucon.de|or:bsb-at-psycho-dot-i21k-dot-de| +--- ceterum censeo javascriptum esse restrictam +
