From: Cesar Rabak <csrabak@yahoo.com.br>
Subject: Re: Alternatives to C: ObjectPascal, Eiffel, Ada or Modula-3?
Date: Tue, 21 Jul 2009 11:45:30 -0300
Date: 2009-07-21T11:45:30-03:00 [thread overview]
Message-ID: <h44kaf$tbs$1@aioe.org> (raw)
In-Reply-To: 19vb3fanruozp.kpikpepa685o.dlg@40tude.net
Dmitry A. Kazakov escreveu:
> On Mon, 20 Jul 2009 22:33:59 -0300, Cesar Rabak wrote:
>
>> Ludovic Brenta escreveu:
>>> Cesar Rabak wrote on comp.lang.eiffel, comp.lang.ada:
>>>> Nicholas Paul Collin Gloucester escreveu:
>>> [...]
>>>>> In this case there is a reason for having more types. An angle and a
>>>>> length are simply not interchangable, so they should not be
>>>>> represented both by Float. The amount of money equal to U.S.$1.00 is
>>>>> not equal to the amount of money equal to 1.00 Canadian dollar, but
>>>>> they are both written with the number 1.00.
>>>> I disagree strongly: an angle in radians is a real number as any other
>>>> there is not any intrinsic difference in its *type* on ordinary
>>>> Mathematics. Dimensionally they are 'pure numbers' with no unit
>>>> atached, your example on monetary units being fallacious, so non
>>>> sequitur.
>>> Ada is not a language for mathematicians (mathematicians would rather
>>> use e.g. Octave), it is a language for engineers. In engineering,
>>> there are very few pure numbers and quite a lot of dimensioned
>>> numbers. As an engineer, I certainly view angles, frequencies and
>>> dimensionless constants (e.g. correction factors) as all having
>>> different dimensions.
>> Nice you bring this, Ludovic! However, remember the OP question:
>> <quote>
>> I'm a CS student and I often need to write number-crunching code dealing
>> with combinatorial optimization problems.
>> What I do usually is implementing ad-hoc algorithms and testing their
>> performance against other previously-known solutions, including general
>> solvers.
>> </quote>
>>
>> So your suggestion is to steer from Ada?
>
> I don't think that Ludovic's example with dimensioned values was a good
> argument. In fact there is no language with a good support of units. Ada is
> not an exception here.
>
I agree.
> As for mathematics, Ada's type system is exactly right thing because it
> supports ADTs. Mathematician would never talk about floats, but reals,
> fields, rings etc. These mathematical structures are ADTs. An individual
> number without specifying the structure where it belongs to is meaningless
> in mathematics.
The support for ADTs in Ada is appropriate for its primary use but for
mathematics it is not enough, except if you don't care of coding a lot
of boilerplate code to have all the consistency you'll need (see
Ludovic's reply to my observation about I/O for example).
> The property of 1 of real and 1 of integer are different.
> This is what the notion of type is about.
You did choose a very peculiar example :-) anyway for an [infinity] of
values your assertion is reasonable true.
>
> For number crunching it is even more important, because numerical methods
> deal with different models of numbers. Even if the domain set is say real
> (R), you might wish to consider to use something different than Long_Float,
> because Long_Float is just a model of R, which might turn unsuitable for
> your needs. Ada allows you to use various models, develop models of your
> own, and design algorithms in terms of a specific model, as well as generic
> ones in terms of some set of models.
Ada here is not as suitable as other languages, which Lisp is a better
example because Floats ultimately map to the underlying HW (a case of
premature optimization), whereas it could store the number as rationals
increasing accuracy and avoiding numerical instability.
However, I agree if the OP is willing to develop the number crunching
algorithms for similar languages (someone wrote in this thread 'Pascal
like') them Ada is OK.
>
> Another important aspect is strong typing, which allows you to concentrate
> on the problem rather than on debugging. Sometimes it is very difficult to
> debug scientific applications like number crunching, because in many cases
> you cannot tell whether the result is right. After all, the task of the
> application is to give a result. If you knew it, you would not need to
> crunch anything...
>
After years working with both strong (and static) typed and more
'dynamic' ones, I disagree on this. Strong static typing plus the need
of the signatures as we're discussing here brings a lot of artifacts
that do not anything to do with the problem to be solved.
For doing experimental work (here as opposed to, say, writing a library
for publishing) I suggest all be done in a dynamic language.
next prev parent reply other threads:[~2009-07-21 14:45 UTC|newest]
Thread overview: 285+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-18 14:19 Alternatives to C: ObjectPascal, Eiffel, Ada or Modula-3? Andrea Taverna
2009-07-18 14:42 ` Richard Harter
2009-07-18 14:53 ` Francois PIETTE
2009-07-18 15:23 ` Ludovic Brenta
2009-07-18 18:27 ` Andrea Taverna
2009-07-18 18:46 ` Pascal Obry
2009-08-04 20:09 ` Hendrik Boom
2009-08-04 21:35 ` Jon Harrop
2009-07-18 18:57 ` Andrea Taverna
2009-07-18 15:18 ` Pascal J. Bourguignon
2009-07-19 13:50 ` Andrea Taverna
2009-07-19 14:06 ` Pascal J. Bourguignon
2009-07-20 10:13 ` Nicholas Paul Collin Gloucester
2009-08-04 20:12 ` Hendrik Boom
2009-07-21 12:03 ` Jon Harrop
2009-07-21 13:25 ` Mark T.B. Carroll
2009-07-18 15:50 ` Ludovic Brenta
2009-07-18 16:31 ` Hibou57 (Yannick Duchêne)
2009-07-18 19:48 ` Georg Bauhaus
2009-07-20 10:34 ` Nicholas Paul Collin Gloucester
2009-07-23 22:58 ` A few Ada questions Andrea Taverna
2009-07-24 0:28 ` Ludovic Brenta
2009-07-24 9:07 ` AdaMagica
2009-07-28 9:48 ` Making a nonlimited type controlled by means of a controlled component Ludovic Brenta
2009-08-14 22:21 ` Randy Brukardt
2009-08-14 22:51 ` Adam Beneschan
2009-07-24 7:00 ` A few Ada questions Dmitry A. Kazakov
2009-07-24 15:26 ` Colin Paul Gloster
2009-07-24 15:01 ` Dmitry A. Kazakov
2009-07-18 16:27 ` Alternatives to C: ObjectPascal, Eiffel, Ada or Modula-3? BGB / cr88192
2009-07-18 17:41 ` Ben Bacarisse
2009-07-20 10:39 ` Nicholas Paul Collin Gloucester
2009-07-20 16:17 ` Ben Bacarisse
2009-07-21 12:10 ` Jon Harrop
2009-07-21 14:40 ` Colin Paul Gloster
2009-07-22 0:25 ` Andrew Reilly
2009-07-19 1:04 ` Andrew Reilly
2009-07-19 13:14 ` mockturtle
2009-07-19 13:35 ` Andrea Taverna
2009-07-19 15:28 ` Pascal J. Bourguignon
2009-07-19 17:30 ` Hibou57 (Yannick Duchêne)
2009-07-19 18:02 ` Georg Bauhaus
2009-07-19 19:09 ` Hibou57 (Yannick Duchêne)
2009-07-19 19:14 ` Pascal J. Bourguignon
2009-07-19 19:51 ` Georg Bauhaus
2009-07-19 19:52 ` tm
2009-07-20 9:57 ` Jean-Pierre Rosen
2009-07-20 13:42 ` Hibou57 (Yannick Duchêne)
2009-07-20 14:37 ` tm
2009-07-20 15:14 ` Jean-Pierre Rosen
2009-07-24 7:26 ` tm
2009-07-24 8:10 ` Dmitry A. Kazakov
2009-07-25 17:39 ` Frank J. Lhota
2009-07-25 18:12 ` Dmitry A. Kazakov
2009-07-24 21:15 ` Wolfgang Ehrhardt
2009-07-24 22:29 ` bartc
2009-07-26 10:55 ` tm
2009-07-26 12:14 ` bartc
2009-07-26 13:21 ` Pascal J. Bourguignon
2009-07-26 15:43 ` bartc
2009-07-20 15:46 ` Georg Bauhaus
2009-07-20 16:08 ` Ben Bacarisse
2009-07-20 19:48 ` Tetrahedral Quartz
2009-07-26 2:26 ` wwilson
2009-07-20 12:15 ` Nicholas Paul Collin Gloucester
2009-07-20 12:59 ` Mark T.B. Carroll
2009-07-20 13:18 ` Nicholas Paul Collin Gloucester
2009-07-20 13:21 ` Mark T.B. Carroll
2009-07-20 14:49 ` Nicholas Paul Collin Gloucester
2009-07-20 18:33 ` Cesar Rabak
2009-07-20 18:49 ` Hibou57 (Yannick Duchêne)
2009-07-20 19:35 ` Cesar Rabak
2009-07-20 21:54 ` Georg Bauhaus
2009-07-21 7:39 ` Dmitry A. Kazakov
2009-07-21 14:30 ` Cesar Rabak
2009-07-21 15:17 ` Martin
2009-07-20 19:23 ` Georg Bauhaus
2009-07-20 19:55 ` Cesar Rabak
2009-07-21 12:49 ` Colin Paul Gloster
2009-07-20 19:44 ` Nicholas Paul Collin Gloucester
2009-07-20 20:14 ` Cesar Rabak
2009-07-20 22:22 ` Ludovic Brenta
2009-07-21 1:33 ` Cesar Rabak
2009-07-21 7:54 ` Ludovic Brenta
2009-07-21 7:59 ` Dmitry A. Kazakov
2009-07-21 13:08 ` Colin Paul Gloster
2009-07-21 12:43 ` Dmitry A. Kazakov
2009-07-21 14:48 ` Cesar Rabak
2009-07-21 14:45 ` Cesar Rabak [this message]
2009-07-21 15:46 ` Dmitry A. Kazakov
2009-07-21 17:34 ` Colin Paul Gloster
2009-07-21 8:56 ` Jean-Pierre Rosen
2009-07-21 9:31 ` Georg Bauhaus
2009-07-21 15:02 ` Cesar Rabak
2009-07-21 16:42 ` Georg Bauhaus
2009-07-21 18:00 ` Cesar Rabak
2009-07-22 14:10 ` Colin Paul Gloster
2009-07-22 14:54 ` Cesar Rabak
2010-03-24 2:46 ` Robert Love
2010-03-25 15:51 ` Colin Paul Gloster
2009-07-21 17:37 ` Colin Paul Gloster
2009-07-21 14:08 ` Hibou57 (Yannick Duchêne)
2009-07-21 13:38 ` Colin Paul Gloster
2009-07-21 15:25 ` Cesar Rabak
2009-07-21 17:48 ` Colin Paul Gloster
2009-07-23 18:47 ` Jon Harrop
2009-07-23 19:20 ` Colin Paul Gloster
2009-07-23 21:51 ` Jon Harrop
2009-07-24 1:08 ` Cesar Rabak
2009-07-24 7:04 ` Dmitry A. Kazakov
2009-07-22 19:29 ` sjw
2009-07-22 20:05 ` Dmitry A. Kazakov
2009-07-23 12:01 ` Colin Paul Gloster
2009-07-24 1:19 ` Cesar Rabak
2009-07-24 8:50 ` Georg Bauhaus
2009-07-24 15:56 ` Colin Paul Gloster
2009-07-24 16:52 ` Colin Paul Gloster
2009-07-24 18:36 ` Cesar Rabak
2009-07-24 21:46 ` Robert A Duff
2009-07-25 14:32 ` jimmaureenrogers
2009-07-25 17:31 ` Cesar Rabak
2009-07-21 12:25 ` Jon Harrop
2009-07-21 11:41 ` Martin
2009-07-21 14:09 ` Jon Harrop
2009-07-21 13:41 ` Martin
2009-07-21 13:45 ` Martin
2009-07-21 13:58 ` Dmitry A. Kazakov
2009-07-21 16:06 ` Jon Harrop
2009-07-21 15:54 ` Georg Bauhaus
2009-07-22 9:37 ` Jon Harrop
2009-07-22 9:19 ` Georg Bauhaus
2009-07-22 7:53 ` Martin
2009-07-22 9:18 ` Jon Harrop
2009-07-21 23:17 ` Robert A Duff
2009-07-21 14:12 ` Andrea Taverna
2009-07-21 14:14 ` Hibou57 (Yannick Duchêne)
2009-07-21 14:38 ` Hibou57 (Yannick Duchêne)
2009-07-21 15:29 ` Mark T.B. Carroll
2009-07-21 16:10 ` Jon Harrop
2009-07-22 8:16 ` Martin
2009-07-22 18:59 ` Jon Harrop
2009-07-24 8:15 ` tm
2009-07-24 9:31 ` Jon Harrop
2009-07-24 9:42 ` Georg Bauhaus
2009-07-24 13:03 ` Jon Harrop
2009-07-24 10:15 ` tm
2009-07-24 13:11 ` Jon Harrop
2009-07-24 13:01 ` tm
2009-07-24 14:42 ` Jon Harrop
2009-07-25 1:15 ` wwilson
2009-07-25 6:05 ` robertwessel2
2009-07-25 9:24 ` Dmitry A. Kazakov
2009-07-26 2:10 ` wwilson
2009-07-26 3:27 ` Andrew Reilly
2009-07-26 10:08 ` bartc
2009-07-27 11:28 ` Colin Paul Gloster
2009-07-28 5:01 ` wwilson
2009-07-28 10:13 ` Colin Paul Gloster
2009-07-28 12:29 ` Dave Seaman
2009-07-28 12:42 ` Peter Hermann
2009-07-28 18:35 ` wwilson
2009-07-21 13:09 ` parnell
2009-07-28 20:57 ` fft1976
2009-07-28 21:59 ` Georg Bauhaus
2009-07-28 22:01 ` Ludovic Brenta
2009-07-30 3:04 ` fft1976
2009-07-30 6:47 ` Martin
2009-07-28 23:14 ` Jon Harrop
2009-08-01 19:46 ` frankenstein
2009-08-01 21:56 ` Paul Rubin
2009-08-01 23:28 ` Jon Harrop
2009-08-02 10:07 ` frankenstein
2009-08-02 18:55 ` Jon Harrop
2009-08-02 9:48 ` frankenstein
2009-07-29 0:40 ` Oxide Scrubber
2009-07-29 2:52 ` fft1976
2009-07-29 4:46 ` Oxide Scrubber
2009-07-29 7:50 ` Elena
2009-07-29 15:06 ` Andrea Taverna
2009-07-29 8:11 ` Ray Blaak
2009-07-29 9:57 ` learn2code
2009-07-29 11:38 ` Oxide Scrubber
2009-07-29 14:03 ` learn2code
2009-07-29 14:35 ` Pascal J. Bourguignon
2009-07-29 17:02 ` Oxide Scrubber
2009-08-03 11:19 ` oxhiderubber
2009-07-29 21:10 ` Jon Harrop
[not found] ` <kctwcdo5pewe.1ut3dcff8axm0$.dlg@40tude.net>
2009-07-29 21:18 ` Jon Harrop
2009-07-29 16:36 ` Colin Paul Gloster
2009-07-29 17:22 ` Ray Blaak
2009-07-29 18:44 ` Martin
2009-07-29 20:58 ` Jon Harrop
2009-07-29 15:19 ` Andrea Taverna
2009-07-29 19:25 ` Jon Harrop
2009-07-30 2:11 ` tmoran
2009-07-30 2:34 ` fft1976
2009-07-30 2:48 ` Paul Rubin
2009-07-30 3:40 ` fft1976
2009-07-30 3:53 ` Paul Rubin
2009-07-30 6:51 ` Georg Bauhaus
2009-07-30 7:52 ` fft1976
2009-07-30 8:34 ` Ludovic Brenta
2009-07-30 16:10 ` Georg Bauhaus
2009-07-30 17:09 ` fft1976
2009-07-30 17:20 ` Pascal Obry
2009-07-30 17:28 ` fft1976
2009-07-30 17:47 ` Isaac Gouy
2009-07-31 10:48 ` Georg Bauhaus
2009-07-30 17:23 ` Ludovic Brenta
2009-07-30 17:59 ` Isaac Gouy
2009-07-30 19:38 ` fft1976
2009-07-30 21:44 ` Isaac Gouy
2009-07-30 22:14 ` Paul Rubin
2009-07-31 10:27 ` Georg Bauhaus
2009-07-31 11:13 ` Georg Bauhaus
2009-07-31 11:29 ` Georg Bauhaus
2009-07-31 16:38 ` Isaac Gouy
2009-07-30 16:25 ` Isaac Gouy
2009-07-30 12:28 ` Colin Paul Gloster
2009-07-30 11:49 ` Martin
2010-03-23 12:31 ` balson
2010-03-23 12:56 ` balson
2010-03-23 13:24 ` Georg Bauhaus
2010-03-23 15:05 ` Maciej Sobczak
2010-03-23 17:52 ` Georg Bauhaus
2010-03-24 6:33 ` Martin Krischik
2010-03-24 8:31 ` Maciej Sobczak
2010-03-23 16:50 ` Warren
2010-03-23 20:29 ` Patrick Scheible
2010-03-24 15:07 ` Warren
2010-03-24 21:11 ` Patrick Scheible
2010-03-24 21:27 ` Pascal J. Bourguignon
2010-03-24 22:14 ` Adam Beneschan
2010-03-24 23:15 ` Patrick Scheible
2010-03-24 23:24 ` Adam Beneschan
2010-03-24 23:28 ` Patricia Shanahan
2010-03-25 1:52 ` John B. Matthews
2010-03-25 16:42 ` Andrew Haley
2010-03-26 23:54 ` Pascal J. Bourguignon
2010-03-24 21:36 ` Adam Beneschan
2010-03-26 7:58 ` Martin Krischik
2010-04-12 11:03 ` Ole-Hjalmar Kristensen
2010-03-24 6:28 ` Martin Krischik
2010-03-24 15:10 ` Warren
2010-03-25 2:19 ` Mike Sieweke
2010-03-25 13:48 ` Robert A Duff
2010-03-25 15:42 ` Colin Paul Gloster
2010-03-26 15:54 ` blmblm
2010-03-26 19:18 ` Warren
2010-03-27 0:03 ` Pascal J. Bourguignon
2010-03-23 17:12 ` J-P. Rosen
2010-03-23 17:41 ` Jim Balson
2010-03-23 17:54 ` Pascal Obry
2010-03-23 18:34 ` jpwoodruff
2010-03-23 20:34 ` Patrick Scheible
2010-03-23 20:33 ` Patrick Scheible
2010-03-23 20:39 ` Pascal Obry
2010-03-24 6:24 ` Martin Krischik
2010-03-23 19:33 ` Adam Beneschan
2010-03-23 22:02 ` Mensanator
2010-03-31 6:55 ` David Thompson
2010-03-31 8:08 ` Martin Krischik
2010-03-24 15:15 ` Warren
2010-03-25 15:46 ` Colin Paul Gloster
2010-03-27 0:53 ` Andrea Taverna
2010-03-27 6:19 ` Gautier write-only
2010-03-23 17:31 ` Patrick Scheible
-- strict thread matches above, loose matches on Subject: below --
2010-03-23 18:57 cbcurl
2010-03-23 20:27 ` John B. Matthews
2010-03-23 21:34 ` Adam Beneschan
2010-03-24 2:08 ` John B. Matthews
2010-03-24 15:23 ` Warren
2010-03-24 16:57 ` Adam Beneschan
2010-03-24 20:00 ` Warren
2010-03-24 20:48 ` Adam Beneschan
2010-03-25 13:45 ` Warren
2010-03-26 8:20 ` Martin Krischik
2010-03-26 19:21 ` Warren
2010-03-28 15:07 ` Martin Krischik
2010-03-29 13:28 ` Warren
2010-03-26 8:05 ` Martin Krischik
2010-03-26 8:02 ` Martin Krischik
2010-03-26 19:24 ` Warren
2010-03-28 14:54 ` Martin Krischik
2010-03-29 13:31 ` Warren
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox