- Haskell - Haskell.org

Happy InstallShield update
by Reuben Thomas 04 Jan '01

04 Jan '01

I just noticed that the Happy 1.9 InstallShield contained a dynamically linked executable for Happy. This was a Bad Idea, so I've replaced it with a statically linked executable. This should work for more people. -- http://sc3d.org/rrt/ | maxim, n. wisdom for fools

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Learning Haskell and FP
by Doug Ransom 04 Jan '01

04 Jan '01

I have read "The Craft of Functional Programming" by Simon Thompson and a few paper on the web. "The Craft" is a good book, but it is an introduction to FP. It seems to me it there are a lot of books on OO design I can pick up at the bookstore, but in the FP world, one must worm their way through all sorts of papers. I have seen papers on Catamorphisms, Monads, Programming with Barbed Wire, folds, etc. I think these papers are hard to understand if you don't have the acadademic/mathematical background -- being papers and not textbooks these papers assume a fair bit of base knowledge. I know I can design a fold function to use in place of primitive recursion for most data structures -- I just don't know if I should. It is pretty easy to get through "The Craft of Functional Programming" without understanding what Category Theory , a Catamorphism , or a Kleisli Composition is. I can see lots of real Software Engineering oppurtunities for these various techniques if I could just put them together. Is there a good textbook on Functional Programming which starts from a base point similar to "The craft of Functional Programming" but more advanced in terms of introducing necessary topics like Category theory, catamorphisms, monads, etc? I would find such a book very useful, especially if it concentrated on lazy functional programming. Doug Ransom Systems Engineer Power Measurement Ltd. http://www.pml.com 250-652-7100 office 250-652-0411 fax mailto:doug_ransom@pml.com

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RE: Learning Haskell and FP
by Simon Peyton-Jones 04 Jan '01

04 Jan '01

| > 1. How the #$!? do I read some data from a file. Good, I've | > got the data, now I can work on it. Nope, now I have an "IO | > thingie" whatever that is, but all of the standard functions want | > a regular "thingie" now what? Perhaps this would be a good moment to advertise the revised version of Tackling the Tackling the Awkward Squad: monadic input/output, concurrency, exceptions, and foreign-language calls in Haskell http://research.microsoft.com/~simonpj/#marktoberdorf (Concerning the thread I'm responding to, it gives an introduction to monadic input/output.) I've revised and extended this tutorial quite a bit since I announced it last year, with a lot of help from people on the Haskell mailing list: thank you! Further suggestions are most welcome. Simon Abstract Functional programming may be beautiful, but to write real applications we must grapple with awkward real-world issues: input/output, robustness, concurrency, and interfacing to programs written in other languages. These lecture notes give an overview of the techniques that have been developed by the Haskell community to address these problems. I introduce various proposed extensions to Haskell along the way, and I offer an operational semantics that explains what these extensions mean.

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RE: Learning Haskell and FP
by Simon Peyton-Jones 04 Jan '01

04 Jan '01

| There is a definite lack of "Getting Started" material in the ghc | distribution. I'm sure that's right. Trouble is, we're the last people qualified to write one! Here's a suggestion: would someone like to write such a guide, from the point of view of a beginner, leaving blanks that we can fill in, when you come across a task or issue you don't know the answer to? That is, you provide the skeleton, and we fill in the blanks. Simon

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GHC/Happy on MacOS X/Darwin
by Atze Dijkstra 03 Jan '01

03 Jan '01

On http://www.cs.uu.nl/~atze/Programming/index.html a version of ghc (4.08.1) and happy (still 1.8) for MacOS X/Darwin can be downloaded. However, a few remarks do apply: this version of ghc is not a completely ported version but built with generic settings and meant as a bootstrapping compiler. It also is distributed as binaries for a specific location (/usr/local/{ghc,happy}) in the UNIX directory structure. The main reasons for distributing it in this unfinished form are: - The MacOS X cc (c compiler) has some (blocking) bugs (for example, problems with asm statements) which hinder progress. - I consider 'unfinished' availability now of greater importance than 'perfect' availability later, so people can play with it. - The compiler seems to run ok, that is, after minimal testing (compiling ghc libraries and a local AG + parsercombinator system). -- - Atze - Atze Dijkstra, Dept. of Computer Science, Utrecht University /|\ Tel.: +31-30-2534093/1454 | WWW : http://www.cs.uu.nl/~atze / | \ Fax : +31-30-2513971 | Email: atze(a)cs.uu.nl /--| \ atze.dijkstra(a)hetnet.nl / |___|

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RE: Learning Haskell and FP
by Simon Peyton-Jones 03 Jan '01

03 Jan '01

| PS: are the members of the list expecting to get replies by | private mail? The thing to do is to switch the thread to haskell-cafe(a)haskell.org haskell@haskell-org is meant for openers; longer threads should move to haskell-cafe. That way people can control how inundated they get. You can "move" by simply adding "-cafe" into the address when you reply. Simon

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Re: Learning Haskell and FP
by Ketil Malde 03 Jan '01

03 Jan '01

"Karl M. Syring" <syring(a)web.de> writes: >> Mind if I "me too" a bit? I had just read the SICP, and I too found >> that the Gentle Introduction served well as an introduction to the >> Haskell syntax. > If you start out with zero knowledge in functional programming, as I do, the > GITH is really not very helpful. Exactly. It's "gentle" if you know functional programming, but probably not otherwise. > PS: are the members of the list expecting to get replies by private mail? Expecting? I'd have no qualms about replying to people privately, but then perhaps I am the obnoxious kind of person. :-) Negative feedback is scarce (although this thread might favorably diverge to -cafe? Followup-To: set). -kzm -- If I haven't seen further, it is by standing in the footprints of giants

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(no subject)
by kh0ndor＠aeiou.pt 03 Jan '01

03 Jan '01

somebody can tell me where I can find some ideas that help me in the construction of a minesweeper programmed in haskell I thank any type of help because I am a little confused __________________________________________________________ Mensagem enviada pelo Xekmail: webmail grátis do AEIOU http://xekmail.aeiou.pt

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Re: Learning Haskell and FP
by Ketil Malde 03 Jan '01

03 Jan '01

George Russell <ger(a)tzi.de> writes: > I think Paul is being unduly modest. I found it very useful when I first learnt > Haskell. But I did already know ML, so maybe the "Gentle Introduction" would be > harder going for someone who didn't know anything about functional programming. Mind if I "me too" a bit? I had just read the SICP, and I too found that the Gentle Introduction served well as an introduction to the Haskell syntax. I think it'd be fine if the title were a bit less ambitious - it isn't really aimed at the novice, I think. It's been a while since I read it tho' -kzm -- If I haven't seen further, it is by standing in the footprints of giants

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RE: List.partition a bit too eager
by Simon Peyton-Jones 02 Jan '01

02 Jan '01

It's a bug in the defn of 'partition' in the Haskell 98 report. I have (still) failed to publish this as an errata, let alone revise the report itself, so the buggy defn stands at present, I'm afraid. I really plan to get to the revision in early '01. Simon | -----Original Message----- | From: George Russell [mailto:ger@tzi.de] | Sent: 22 December 2000 15:57 | To: haskell(a)haskell.org | Subject: List.partition a bit too eager | | | I think the following program | | import List | main = putStr . show . fst . (partition id) . cycle $ [True,False] | | should display [True,True,True,...]. But instead, for both | GHC and Hugs, | you get a stack overflow. Is this a bug, or could someone | explain it to me? | | _______________________________________________ | Haskell mailing list | Haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell |

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