- Haskell-Cafe - Haskell.org

example editrc
by brian 23 Dec '08

23 Dec '08

This is making ghci with editline nicer for me. It says to use the vi key mapping, tab for completion, C-l to clear the screen, and jj to go into vi command mode. $ cat ~/.editrc bind -v bind \\t rl_complete bind ^L ed-clear-screen bind jj vi-command-mode

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Initializing GHC from Python
by Ron de Bruijn 23 Dec '08

23 Dec '08

Hi, We have just published a small article on how one can initialize GHC from Python, with only optional use of C. You can read it at http://gamr7.com/blog/?p=65 . Best regards, Ron de Bruijn

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New Haskell logo contest
by Fritz Ruehr 23 Dec '08

23 Dec '08

I think this logo contest is a great idea. I submitted my "classy Haskell" logo from the merch. page, but I have to admit I like some of the other ones on the submission page a whole lot. Hey, *here's* an idea: maybe whoever wins the logo contest has to take over management of the Haskell merchandise page on CafePress! :) -- Fritz Ruehr

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cabal, multi-file applications
by Cetin Sert 23 Dec '08

23 Dec '08

Hi, I get the following error message: cetin@unique:~/lab/test/qths/hnm$ make configure runhaskell Setup.hs configure Configuring HNM-0.2... cetin@unique:~/lab/test/qths/hnm$ make build runhaskell Setup.hs build Preprocessing library HNM-0.2... Preprocessing executables for HNM-0.2... Building HNM-0.2... demo3.hs:4:7: Could not find module `HNM.WLAN': Use -v to see a list of the files searched for. make: *** [build] Error 1 when I try to build the following program: http://sert.homedns.org/hs/hnm/ http://sert.homedns.org/hs/hnm/hnm.cabal How can I tell in my cabal file that wlan.hs should be built first than settings.hs than demo3.hs? Best Regards, Cetin Sert

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[Byte8] <-> ByteString
by Galchin, Vasili 23 Dec '08

23 Dec '08

Hello, I have been reading through Data->ByteString. What is the is most elegant and efficient way to map/unmap [Byte8] <-> ByteString? Thanks, Vasili

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Cabal Install & Links to Source from Haddock Docs
by R Hayes 23 Dec '08

23 Dec '08

Is there a way I can get Haddock Docs WITH links to source (local) from modules installed with "cabal install xxx"? Getting the docs themselves is pretty easy by changing either ~/.cabal/ config or using --enable-documentation. Automatically generating the source (colourised or not) and integrated links eludes me. -r

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Re: understanding enumerator/iteratee
by oleg＠okmij.org 23 Dec '08

23 Dec '08

Artyom Shalkhakov wrote > I would say that it [iteratee] just tells us how to react to various forms of > input. :) This is much like the function you pass to foldr. Precisely. To sum up all elements of Data.Map, we do Map.fold (+) 0 mp to sum up all elements of a set we do Set.fold (+) 0 st ditto for any other foldable data structure. Clearly the function that sums the current element with the accumulator, (+), doesn't know or care from which collection the elements are coming from. The initial seed, 0, is again unaware of the collection. Iteratee is indeed the function that you pass to fold (combined with the seed for practical reasons). One may conceptually consider iteratee to be a pair of the function to feed to fold, and the initial seed (the accumulator in the above example). That achieves the separation of concerns: fold (aka, enumerator) has the intimate knowledge of the collection and how to get to the next element; iteratee knows what to do with the current element.

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Takusen
by Günther Schmidt 23 Dec '08

23 Dec '08

Hi all, where can I find some sample code or other examples to familiarize me with Takusen? Does Takusen use safe ccall only, or does it also use ccall unsafe? Günther

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A hell of a question
by Andrzej Jaworski 23 Dec '08

23 Dec '08

I just want to say Hello to let you know that there are some serious entities watching you besides monads and FBI:-) There has been a hell of a discussion recently about logos, languages and religion and I want to add to this. First let me disassociate Haskell from Taoism which to may taste has left us in an unhealthy climate. It suffices to say that Taoism is a school of clever trics and cute aphorisms but without the slightest attempt to explain or generalize let alone produce an abstract idea or a system. That is why its wisdom is non transferable in spite of majority of humans desending from it. Haskell on the contrary is a minority school that implements abstract ideas for problem solving in the most transferable way to date, so that other languages look into it for their share. But don't worry, thay will choke becouse it is them who practice Taoizm. Playing too many tricks will eventually trick them, even if some are powerful enough to brainwash dicent professors to preach interoperability or the like. Every viable complexity needs a single underlying concept to survive, including you and the universe. Microsoft and the like excluding;-) Haskell has all that: consistency, transparency and self-contained concept. However Haskell is also somehow asynchronic with the Bible as it is condemned to perpetual purity only to be saved from it via monads, which according to Spinoza "are arranged by God in a perfect order which ascends to God, the supreme monad!!!". Thus we can look at Haskell's purity as a kind of harmless attempt to play God by means of incapsulating the world only to ignor it. This could somehow put it in the same boat with the devil. They both prefer your brain to Turing machin:-) I would leave with the eternal question "what the hell Haskell is?" and with my Santa Close emphasising Haskell's purity and my simplicity. Here: http://haskell.org/sitewiki/images/7/79/WCF.Andrzej.Jaworski.gif Have fun, -Andrzej Jaworski

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OpenAL
by brian 22 Dec '08

22 Dec '08

Does the example code at http://articles.bluishcoder.co.nz/Haskell/OpenAL work for anyone? I added some putStrLns to see the device and context, and get $ ./Main2 Device (ALCdevice 0x08a744c8) Context (ALCcontext 0x08aabda0) AL lib: alSource.c:2291: alcDestroyContext(): 1 Source(s) NOT deleted AL lib: alBuffer.c:1097: exit() 2 Buffer(s) NOT deleted and no sound. I had more complex code using OpenAL working some time ago, but the sound was crackly because my distribution used the original OpenAL implementation. Now that people are switching to OpenAL Soft, Haskell's OpenAL seems to be acting strangely. I mailed Sven in September, but didn't hear back.

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