From: "Peter C. Chapin" <pcc482719@gmail.com>
Subject: Re: SPARK
Date: Sat, 15 May 2010 09:09:08 -0400
Date: 2010-05-15T09:09:08-04:00 [thread overview]
Message-ID: <4bee9bea$0$2405$4d3efbfe@news.sover.net> (raw)
In-Reply-To: op.vcnkzltoule2fv@garhos
Yannick Duchêne (Hibou57) wrote:
>>
>> f(g(I) + f(f(g(I)))**2,
>>
>> or to
>>
>> f(f(g(I))) + f(g(I))**2.
> A function optimized (which save computing of already computed inputs)
> using memoisation, does not exposes this behavior.
If it works properly, yes, but what if it doesn't?
> How to make it formal : may be giving the proof the function is the only
> one to access memoisation storage between function invokation, so, that
> this data are mechanically private to the function. Then, demonstrate
> there is two paths to the result : one which is the basic computation and
> one which retrieve the result of a similar previous computation. This
> latter step could rely on the computation of a key to access this data.
> Then demonstrate that for a given input, the computed key is always the
> same (input <-> key association). Now, the hard part may be to demonstrate
> the key is used to access the result which was computed previously for the
> same input that the one which was used to compute the key.
>
> Obviously, the function should be the only one to access this data.
>
> There is a concept in SPARK, the one of variable package and
> state-machines. May be there could be some room for a concept which could
> be something like function-package ?
While this might be possible, it does sound rather complicated. I can see why
SPARK doesn't currently go down this path.
Peter
next prev parent reply other threads:[~2010-05-15 13:09 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-12 22:55 SPARK Yannick Duchêne (Hibou57)
2010-05-13 0:52 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 3:06 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 9:28 ` SPARK stefan-lucks
2010-05-13 16:48 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 13:09 ` Peter C. Chapin [this message]
2010-05-14 22:55 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 4:00 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 16:54 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 17:15 ` SPARK Rod Chapman
2010-05-13 19:43 ` SPARK Yannick Duchêne (Hibou57)
2010-05-13 20:05 ` SPARK Rod Chapman
2010-05-13 21:43 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 14:47 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 1:20 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 4:15 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 8:17 ` SPARK Phil Thornley
2010-05-14 9:32 ` SPARK Rod Chapman
2010-05-14 14:20 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 3:07 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 3:26 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 8:11 ` SPARK Phil Thornley
2010-05-14 14:28 ` SPARK Yannick Duchêne (Hibou57)
2010-05-14 21:45 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 16:41 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 18:00 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 18:14 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 19:08 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 20:23 ` SPARK Yannick Duchêne (Hibou57)
2010-05-16 18:13 ` SPARK Peter C. Chapin
2010-05-17 0:59 ` SPARK Yannick Duchêne (Hibou57)
2010-05-16 18:17 ` SPARK Phil Thornley
2010-05-17 1:24 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 18:43 ` SPARK Phil Clayton
2010-05-15 19:12 ` SPARK Yannick Duchêne (Hibou57)
2010-05-15 21:02 ` SPARK Phil Clayton
2010-05-15 22:48 ` SPARK Yannick Duchêne (Hibou57)
2010-05-16 1:48 ` SPARK Yannick Duchêne (Hibou57)
2010-05-16 1:53 ` SPARK Yannick Duchêne (Hibou57)
2010-05-16 5:28 ` SPARK Yannick Duchêne (Hibou57)
2010-05-18 18:01 ` SPARK Yannick Duchêne (Hibou57)
2010-05-19 8:09 ` SPARK Phil Thornley
2010-05-19 20:38 ` SPARK Simon Wright
2010-05-19 21:27 ` SPARK Yannick Duchêne (Hibou57)
2010-05-20 6:21 ` SPARK Simon Wright
2010-05-20 6:58 ` SPARK Yannick Duchêne (Hibou57)
2010-05-20 21:51 ` SPARK Simon Wright
2010-05-19 21:35 ` SPARK Yannick Duchêne (Hibou57)
-- strict thread matches above, loose matches on Subject: below --
2009-06-10 9:47 SPARK Robert Matthews
2004-08-18 23:46 timeouts Brian May
2004-08-19 3:40 ` timeouts Steve
2004-08-22 4:18 ` timeouts Brian May
2004-08-22 12:54 ` timeouts Jeff C,
2004-08-26 1:28 ` timeouts Brian May
2004-08-26 13:34 ` timeouts Steve
2004-08-26 14:02 ` timeouts Georg Bauhaus
2004-08-26 23:03 ` SPARK Brian May
2004-08-27 10:11 ` SPARK Georg Bauhaus
2001-08-08 9:46 SPARK Soeren.Henssel-Rasmussen
2001-08-08 20:04 ` SPARK McDoobie
2001-08-06 16:49 SPARK programmer
2001-08-07 7:04 ` SPARK Hambut
2001-08-07 7:18 ` SPARK Hambut
2001-08-07 8:37 ` SPARK Peter Amey
2001-08-07 14:42 ` SPARK McDoobie
2001-08-09 12:36 ` SPARK Peter Amey
2001-08-14 3:14 ` SPARK Prof Karl Kleine
2001-08-14 10:25 ` SPARK Rod Chapman
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