Software Quality in Science
in [ADA]
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From: Georg Bauhaus on 15 Feb 2010 07:19 Colin Paul Gloster schrieb: > On Wed, 10 Feb 2010, Stephen Leake wrote: > > |---------------------------------------------------------------------| > |"[..] | > | | > |The programmers still have to specify the right switches, and pay | > |attention to the results, and know how to fix them, which is a | > |political/management/skill issue, not a language design issue. | > | | > |I know from personal experience that there is a satellite about to be| > |launched who's control code has many remaining C warnings. Sigh." | > |---------------------------------------------------------------------| > > Yes, people are idiots. For making decisions (e.g. about ignoring warnings), programmers just have a proven set of rules. This set is defined by a certain rationality, which is bounded, and not just technical: it is also imposed by tradition, knowledge, and management. It does sometimes make sense ---post hoc at least. If this situation helps you live a peaceful life with your family and friends, why bother with messy warnings at work? At work, if the leading staff, adequately payed, thinks you should not ignore warnings, then have them say when, and when not, to treat warnings as errors. Or, at least have them delegate responsibility for defects to you. OK, the latter is an unrelated issue.
From: Colin Paul Gloster on 15 Feb 2010 07:18 On Thu, 11 Feb 2010, Brian Drummond wrote: |-----------------------------------------------------------------------------| |"[..] | |> | |>I surprised (if confirmed) that FORTRAN (which I've never experienced) | |>is even less safe than C. | | | |It certainly can be. | | | |Mis-spell a variable name, and you have just declared a new one, not accessed| |the one you expected... (There are usually ways to turn implicit declarations| |off, or make them compile time errors or warnings.)" | |-----------------------------------------------------------------------------| Some compilers for Fortran are better than Fortran. There is no way in Fortran to enforce these sanity checks. Unlike the Ada standards, the Fortran standards do not require illegal programs to be rejected by the compilers: merely that legal programs be run correctly.
From: Hibou57 (Yannick Duchêne) on 15 Feb 2010 09:43 Le Mon, 15 Feb 2010 12:08:11 +0100, Colin Paul Gloster <Colin_Paul_Gloster(a)acm.org> a écrit: > I am a nuclear scientist, and I confirm that software used for > supposedly simulating nuclear reactions is dangerous. For example, > HTTP://HyperNews.SLAC.Stanford.edu/HyperNews/geant4/get/phys-list/545.html Strange, he looks hesitating -- No-no, this isn't an oops ...or I hope (TM) - Don't blame me... I'm just not lucky
From: Maciej Sobczak on 15 Feb 2010 09:52 On 15 Lut, 12:20, Colin Paul Gloster <Colin_Paul_Glos...(a)ACM.org> wrote: > if (condition) statement; In Ada that would be: if Condition then Statement; end if; which is equally ugly. Could you clarify your point? -- Maciej Sobczak * www.msobczak.com * www.inspirel.com Database Access Library for Ada: www.inspirel.com/soci-ada
From: Colin Paul Gloster on 15 Feb 2010 13:48
On Wed, 10 Feb 2010, Florian Weimer wrote: |-------------------------------------------------------------------| |"[..] | | | |even lines of code) vary as much among programmers [..]" | |-------------------------------------------------------------------| Colin Paul Gloster responded: |----------------| |"Of course. [..]| | | |[..]" | |----------------| On Mon, 15 Feb 2010, Maciej Sobczak wrote: |------------------------------------------------------------------| |"On 15 Lut, 12:20, Colin Paul Gloster <Colin_Paul_Glos...(a)ACM.org>| |wrote: | | | |> if (condition) statement; | | | |In Ada that would be: | | | |if Condition then Statement; end if; | | | |which is equally ugly. | |Could you clarify your point?" | |------------------------------------------------------------------| Of course <=> Yes. Yes even #lines of code vary among programmers. Given one programmer and C++ then if (condition) statement; would result whereas changing the language but not the programmer would result in if Condition then Statement; end if; A different programmer would produce if (condition) { statement; } or if Condition then Statement; end if; depending on language. Yet a different programmer would produce if (condition { statement; } or if Condition then Statement; end if; depending on language. |