December 2002 - Haskell

Oops, another H'98 report error.
by Malcolm Wallace 04 Dec '02

04 Dec '02

I know it is no far too late to do anything about it, but I just discovered another error in the Haskell'98 Libraries Report. The Time module exports all but one of the fieldnames of the CalendarTime datatype, bizarrely omitting ctSec. Regards, Malcolm

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RE: ANNOUNCE: GHC version 5.04.2 released
by Simon Marlow 04 Dec '02

04 Dec '02

> ============================================================== > The (Interactive) Glasgow Haskell Compiler -- version 5.04.2 > ============================================================== > > We are pleased to announce a new patchlevel release of the Glasgow > Haskell Compiler (GHC), version 5.04.2. This is a bugfix-only > release. For all the changes since 5.02.3, see the release notes: > > > http://www.haskell.org/ghc/docs/latest/users_guide/release-5-04.html Oops, that URL should be http://www.haskell.org/ghc/docs/latest/html/users_guide/release-5-04.htm l Cheers, Simon

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Re: The Haskell 98 Report
by cwitty＠newtonlabs.com 04 Dec '02

04 Dec '02

"Claus Reinke" <claus.reinke(a)talk21.com> writes: > So, as a small token, I've revised my original plan and will now buy one > of the printed versions (I shall also place higher priority on submitting > to JFP in the future;-). Let's support forward-looking publishers! > > Thanks, Simon, and thanks, Conrad Guettler & CUP! I agree totally (I wasn't going to buy a copy, but now I will). Please let us know when the book becomes available through online bookstores... Thanks, Simon and Conrad! Carl Witty

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AW: slide: useful function?
by Markus.Schnell＠infineon.com 03 Dec '02

03 Dec '02

Thanks for the comments. It seems the function is not really needed (at least not predefined), although I use it fairly often. > Read more in > > T Uustalu, V Vene. The dual of substitution is redecoration. > In K Hammond, S Curtis, eds, Trends in Functional Programming > 3, pp 99-110. Intellect, > Bristol / Portland, OR, 2002. - .ps.gz, 46K (© Intellect) > > http://www.cs.ioc.ee/~tarmo/papers/sfp01-book.ps.gz , > > if you want to be bothered with categorical nonsence ;-) There's too much mathematics in it, I'm only an engineer... ;-) Thanks, Markus -- Markus Schnell, Infineon Technologies AG

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Mathematics and Software Engineering (was slide: useful function? )
by Markus.Schnell＠infineon.com 03 Dec '02

03 Dec '02

> > There's too much mathematics in it, I'm only an engineer... ;-) Perhaps I should rephrase: > There's too much mathematics in it, I'm not a mathematician > reminds of what I think is one of the biggest problems with > conventional > software development: the lack of appreciable mathematics in the > specification, design, coding, or implementation of programs. In this While this is surely true, I think, there is also a lack of communication between software engineers. Civil, Mechanical or Electrical Engineers have well-established plans, while software engineers have not (see http://fmc.hpi.uni-potsdam.de/) One should not forget, that many practical problems are not solvable by a rigorous mathematical approach. German reading people may have a look at http://fmc.hpi.uni-potsdam.de/research/literature/wendt_1998-kommunikationsp roblem_der_informatiker.pdf, where some problems are pointed out (with an edge to it). > sense there is a huge contrast between conventional software > development > practice and other engineering disciplines. Definitely. But software development is probably not old enough... It's like the difference between somebody bying some Radio Shack stuff and putting it together until it works, and an engineer making informed decisions for layout and choice of elements for a circuit. This informedness relies partly on mathematics, but at least as much on experience and pragmatics. Most software people are still bying Radio Shack stuff... (and isn't it easy?) > I was once an electrical > engineer, and I used lots of mathematics (not just in school, but in > industry), and I know that most other engineering disciplines > also use a So you know that to use diracs and fourier you don't necessarily need to understand what functionals are about. Likewise, it's not necessary to understand category theory to use monads and the like. > lot of mathematics. One of the things I like about FP is that it > demands more mathematical sophistication of its practitioners, which, > contrary to some opinions, I think is a Good Thing. I'm fully with you there, but - as someone already pointed out - I don't want to need a math major to read a paper regarding programming. This doesn't mean there is something wrong with these papers, it's just that I wished there would be more accessible versions. Hope to got my point across, Markus -- Markus Schnell, Infineon Technologies AG

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Calling ghc dll's with MSVC++ code
by Mauricio Carvalho 03 Dec '02

03 Dec '02

Hey! I need to call haskell DLL's from a c++ program, and this C++ is written in Microsoft's Visual C++ 6.0 I created the DLL sing the directives given at ghc user's guide (11.3 and 11.4) and created the dll. To create a .lib import file, I linked with the option -optdll--output-lib -optdllMyDll.lib I can compile and link my C++ problem, but when I run it, it crashes. I tried even to create a DLL from a C source I'm sure it works (as I created the DLL before with MSVC++ environment, and I could make it work out), and even this DLL crashes whe its functions are accessed. I'm using GHC 5.0.4.1 Is there some special command lines that must be used to create DLLs to be used with windows? Or is there some known difficulty doing it? Someone that succeded can please tell me exactly how was it done? If more info is needed, I can send the sources and command lines I used to compile. ps: I'm not using cygwin (i don't have it installed in my computer actually), but as far as I understood, it shouldn't be a problem ´Thanks for help! Mauricio

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The Haskell 98 Report
by Simon Peyton-Jones 01 Dec '02

01 Dec '02

Folks, As you know, Cambridge University Press are doing us the huge service of publishing the Haskell 98 report, both as a special issue of the Journal of Functional Programming (Jan 2003) and as a hardback book (it'll cost around £35). I'm very, very, very happy to say that, following discussion with CUP, the copyright and reproduction arrangements for the report will remain unchanged; i.e. exactly as they are at: http://research.microsoft.com/~simonpj/haskell98-revised/haskell98-report-h… I'm signing a letter that grants CUP a *non-exclusive* license to publish the Report, but it places no limitations on what else may be done with it. The copyright will still be (c) Simon Peyton Jones (as it has for some while; it has to be attached to someone or some thing), and the existing notice that says "you can do what you like with this Report" will stay unchanged. No "non-commercial only" caveats. In my view this is extremely generous of CUP, and I am particularly grateful to Conrad Guettler for making it happen. As a thank-you to CUP, perhaps you can all go out and buy a copy! Simon

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