Re: [Haskell-cafe] Fair diagonals (code golf)
On Wed, Nov 04, 2009 at 07:01:50PM +0100, Sjoerd Visscher wrote: To: Haskell Cafe haskell-cafe@haskell.org From: Sjoerd Visscher sjo...@w3future.com Date: Wed, 4 Nov 2009 19:01:50 +0100 Subject: Re: [Haskell-cafe] Fair diagonals (code golf) The code by Twan can be reduced to this: diagN = concat . foldr f [[[]]] f :: [a] - [[[a]]] - [[[a]]] f xs ys = foldr (g ys) [] xs g :: [[[a]]] - a - [[[a]]] - [[[a]]] g ys x xs = merge (map (map (x:)) ys) ([] : xs) merge :: [[a]] - [[a]] - [[a]] merge [] ys = ys merge xs [] = xs merge (x:xs) (y:ys) = (x++y) : merge xs ys But my feeling is that this can still be simplified further. Or at least refactored so it is clear what actually is going on! i wrote another solution: diag2 xs ys = join . takeWhile (not . null) . map f $ [1..] where f i = zip xs' ys' where xs' = take i $ drop (i - length ys') xs ys' = reverse $ take i ys diag [] = [] diag [q] = [q] diag qs = foldr f (map (:[]) $ last qs) (init qs) where f q' = map (uncurry (++)) . diag2 (map (:[]) q') diag is the recursion step over the dimensions; diag2 is the base case with two dimensions. i can see that it's less efficient on (partially) finite inputs, since i keep dropping increasing prefixes of xs and ys in the local f in diag2), and there are probably other issues. but it was fun staring at this problem for a while. :) matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Merging modules
On Fri, Oct 16, 2009 at 11:42:22AM +0100, pat browne wrote:
To: haskell-cafe@haskell.org
From: pat browne patrick.bro...@comp.dit.ie
Date: Fri, 16 Oct 2009 11:42:22 +0100
Subject: [Haskell-cafe] Merging modules
Hi,
I want to establish the strengths and weakness of the Haskell module
system for the ontology merging task (I know it was not designed for
this!). I wish to make a new module (MERGEDONTOLOGY) from three input
modules one of which is common to the other two.
The desired merge should contain the following data types:
Woman FinancialBank HumanBeing RiverBank
Which are all identifiable without any qualifying module names.
Below is the detailed requirement and my first attempt at this task in
Haskell. I would be grateful for any information on how to merge these
modules giving a set of unique unqualified types (i.e. without reference
to their originating modules).
Regards,
Pat
Informal Specification
The diagram and text below explain the requirement
MERGEDONTOLOGY
{ Woman, RiverBank, FinancialBank, HumanBeing}
/\ /\
/ \
/\
/ \
/ \
/ \
/ \
ONTOLOGY1 ONTOLOGY2
{Woman, Bank, Person} {Woman, Bank, Human}
/\ /\
\ /
\ /
\ /
\ /
\ /
\ /
\ /
{Woman , Person}
COMMMON
This example includes both synonyms and homonyms.
1)The Woman sort (or data type) should be the same in all modules, there
is only one Woman sort and it is named as such in each module. Hence
there should be only one MERGEDONTOLOGY.Woman.
2)There is only one sort MERGEDONTOLOGY.HumanBeing, but there are 3
synonyms for it called ONTOLOGY2.Human, ONTOLOGY1.Person, and
COMMON.Person. The last sentence considers ONTOLOGY1.Person and
COMMON.Person as synonyms; they have different qualifiers but the
intention is that they represnt the same thing. Hence should be mapped
to same MERGEDONTOLOGY.HumanBeing. To do this (in Maude) COMMON.Person
was renamed to ONTOLOGY2.Human which in turn was renamed to
MERGEDONTOLOGY.HumanBeing.
3)The homonyms are ONTOLOGY1.Bank and ONTOLOGY2.Bank should become
distinct sorts MERGEDONTOLOGY.RiverBank and
MERGEDONTOLOGY.FinancialBank in the final ontology at the top of the
diagram.
My first attemt at merging using Haskell modules
=
module COMMON where
data Woman = WomanC
data Person = PersonC
module ONTOLOGY1 where
import COMMON
data Bank = BankC
module ONTOLOGY2 where
import COMMON
data Bank = BankC
module MERGEDONTOLOGY where
import ONTOLOGY1
import ONTOLOGY2
If I use qualified names all the constructors are interpreted correctly
MERGEDONTOLOGY :t COMMON.WomanC
COMMON.WomanC :: COMMON.Woman
MERGEDONTOLOGY :t COMMON.PersonC
COMMON.PersonC :: COMMON.Person
MERGEDONTOLOGY :t ONTOLOGY2.BankC
ONTOLOGY2.BankC :: ONTOLOGY2.Bank
MERGEDONTOLOGY :t ONTOLOGY1.BankC
ONTOLOGY1.BankC :: ONTOLOGY1.Bank
MERGEDONTOLOGY :t COMMON.Woman
However, I wish that these types and constructors be fully defined in
the context of the MERGEDONTOLOGY. I have tried type synonyms and newtypes.
type RiverBank = ONTOLOGY1.Bank
type FinancialBank = ONTOLOGY2.Bank
newtype RiverBank = BankC Int
I have not explored import modes or qualified imports.
The way you import ONTOLOGY* and COMMON without qualified, you can
use any name that you import without qualifier, as long as the name is
unique over all imported modules.
Where names would conflict, you can list the names to be imported
explicitly, and omit the names that cause conflicts:
import ONTOLOGY1 (Woman (..), Person (..))
or list the names to be omitted:
import ONTOLOGY1 hiding (Bank (..))
In your example, you want both banks (from both ontologies), and name
them differently. If this is a common thing in your application,
perhaps you want to use type classes instead of plain data types, or
one of the other many extensions
Re: [Haskell-cafe] Merging modules
On Fri, Oct 16, 2009 at 12:56:30PM +0100, pat browne wrote: To: haskell-cafe@haskell.org From: pat browne patrick.bro...@comp.dit.ie Date: Fri, 16 Oct 2009 12:56:30 +0100 Subject: Re: [Haskell-cafe] Merging modules This is all pretty basic stuff. Not sure any of it is very helpful. (Why do you want to spread an ontology over several Haskell modules?) -matthias Yes it is very helpful, I have limited time to study Haskell. excellent (: The reason for spreading the information over modules is to simulate actual ontologies and the mappings to other ontologies. My next step is, as you suggested, to use type classes. My overall thesis is the study of current algebraic specification and programming techniques. another thing you may want to know about is template haskell (what haskellers use instead of lisp macros). instead of creating trivial type instances for hundrets or thousands of type classes, you can call one macro for each class / data pair that unfolds into both. this may make your source code a lot more concise and elegant. please post the outcome of this if you can find the time. cheers, matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] statistics package and randomness
i'll try a very non-technical explanation that has worked for me so far. (is it correct? does it make sense?) IO and ST are quite similar. the difference is that whereas IO gives you a concept of time in the world surrounding your code, ST lets you create a little bubble inside your code in which you can maintain state, while the bubble as a whole acts all pure and lazy. for example, if you want to implement an algorithm that writes to and reads from a matrix, you use ST: you want to control the order in which you read from and write to it, but not the order in which access events to that data structure mixes with user interaction events. -matthias On Mon, Oct 12, 2009 at 12:25:43AM -0700, Michael Mossey wrote: To: Haskell Cafe Haskell-Cafe@haskell.org Cc: From: Michael Mossey m...@alumni.caltech.edu Date: Mon, 12 Oct 2009 00:25:43 -0700 Subject: [Haskell-cafe] statistics package and randomness I'm trying to learn how to use randomness in Haskell and it seems very non-straightforward and complex. I could do a lot of things using 'split' from System.Random, but apparently it's broken. There is the statistics package here: http://hackage.haskell.org/package/statistics Is this a better solution? It uses the ST monad in the RandomVariate module. Can someone point me to a tutorial explaining ST, and/or a tutorial in the RandomVariate module? Pseudorandomness seems like one case where it would just be a hell of a lot simpler to have a global generator--never split the state. Is the ST monad some way to accomplish this? Thanks, Mike ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 5.5394 Best match to file #0 (nonspam.css) prob: 1. pR: 5.5394 Total features in input file: 2960 #0 (nonspam.css): features: 758386, hits: 2888631, prob: 1.00e+00, pR: 5.54 #1 (spam.css): features: 1683715, hits: 3150692, prob: 2.89e-06, pR: -5.54 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do I get this done in constant mem?
On Sat, Oct 10, 2009 at 11:11:24PM +0200, Daniel Fischer wrote: To: haskell-cafe@haskell.org From: Daniel Fischer daniel.is.fisc...@web.de Date: Sat, 10 Oct 2009 23:11:24 +0200 Subject: Re: [Haskell-cafe] How do I get this done in constant mem? Am Samstag 10 Oktober 2009 22:14:38 schrieb mf-hcafe-15c311...@etc-network.de: On Sat, Oct 10, 2009 at 09:33:52AM -0700, Thomas Hartman wrote: To: Luke Palmer lrpal...@gmail.com Cc: mf-hcafe-15c311...@etc-network.de, haskell-cafe@haskell.org From: Thomas Hartman tphya...@gmail.com Date: Sat, 10 Oct 2009 09:33:52 -0700 Subject: Re: [Haskell-cafe] How do I get this done in constant mem? Yes, you should not do this in IO. That requires the entire computation to finish before the result can be used. Not really the entire computation though... whnf, no? In that example, yes. But readFile takes the entire file into a strict String before it gives you the first Char, right? (Sorry again for my misleading code simplification.) No, readFile reads the file lazily. hm? oh, you are right, now that i fixed all the other problems in my code readFile isn't a problem any more either... (-: (but then how does it know when to close the handle? gotta go read the code i guess.) thanks! -m ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do I get this done in constant mem?
On Fri, Oct 09, 2009 at 05:48:15PM -0600, Luke Palmer wrote: To: mf-hcafe-15c311...@etc-network.de Cc: From: Luke Palmer lrpal...@gmail.com Date: Fri, 9 Oct 2009 17:48:15 -0600 Subject: Re: [Haskell-cafe] How do I get this done in constant mem? On Fri, Oct 9, 2009 at 2:05 PM, mf-hcafe-15c311...@etc-network.de wrote: Hi all, I think there is something about my use of the IO monad that bites me, but I am bored of staring at the code, so here you g. The code goes through a list of records and collects the maximum in each record position. -- test.hs import Random import System.Environment (getArgs) import System.IO (putStr) samples :: Int - Int - IO [[Double]] samples i j = sequence . replicate i . sequence . replicate j $ randomRIO (0, 1000 ** 3) Yes, you should not do this in IO. That requires the entire computation to finish before the result can be used. This computation should be pure and lazy. Yeah. I also got an excellent reason via private mail why sequence has to be strict: sequence [Maybe 3, Maybe 4, Nothing] = Nothing sequence [Maybe 3, Maybe 4] = Just [3, 4] maxima :: [[Double]] - [Double] maxima samples@(_:_) = foldr (\ x y - map (uncurry max) $ zip x y) (head samples) (tail samples) FWIW, This function has a beautiful alternate definition: maxima :: [[Double]] - [Double] maxima = map maximum . transpose Beautiful indeed! But see below. To be honest, I don't really roll dice, but I am reading from a file. I just thought that randomRIO would be more concise, but now the discussion has gone totally in that direction. Sorry... (-: reading the random number code is more fun, though! Anyhow, I fixed my example to do lazy file processing where before I used readFile (which has to be strict, as I can see now). First, I generate a file with the samples, and then I read that file back (this is the phase I'm interested in, since my real data is not really random numbers). import List import Monad import Random import System.Environment import System.IO samples :: Int - Int - IO [[Int]] samples i j = sequence . replicate i . sequence . replicate j $ randomRIO (0, 1000 * 1000 * 1000) maxima :: [[Int]] - [Int] maxima samples@(_:_) = foldr (\ x y - map (uncurry max) $ zip x y) (head samples) (tail samples) lazyProcess :: ([[Int]] - a) - FilePath - IO a lazyProcess f fileName = do h - openFile fileName ReadMode v - fmap (f . map read . lines) $ hGetContents h v `seq` hClose h return v mkSamples = do args - getArgs x - samples (read (head args)) 5 putStr . (++ \n) . join . intersperse \n . map show $ x -- main = mkSamples -- ghc --make -O9 test.hs -o test ./test 1 test.data main = lazyProcess length test.data = putStr . show lazyProcess (What would be a better name? foldSampleFile perhaps?) is where the IO happens, but the computation is located in a pure function. And yet, only those lines are read that are relevant, and GC on previous lines is allows if the pure function allows it. This program has constant memory usage. Unfortunately, if I replace the length function with implementation of maxima, it explodes again. I tried a few things, such as maxima'3 :: [[Int]] - [Int] maxima'3 (h:t) = foldr (\ x y - let v = map (uncurry max) $ zip x y in sum v `seq` v) h t with no luck so far. Tricky business, that! But much more curiously, if I replace maxima'3 in main with this maxima'4 :: [[Int]] - [Int] maxima'4 = map maximum . transpose (with explicit type signature in both definitions), I get a 'no parse' error from Prelude.read. maxima'3 with the same file gives me a result. How can there be a difference if the type signatures are identical?! Probably something about don't use Prelude.read :-)? I have to play with this some more... matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How do I get this done in constant mem?
On Sat, Oct 10, 2009 at 09:33:52AM -0700, Thomas Hartman wrote: To: Luke Palmer lrpal...@gmail.com Cc: mf-hcafe-15c311...@etc-network.de, haskell-cafe@haskell.org From: Thomas Hartman tphya...@gmail.com Date: Sat, 10 Oct 2009 09:33:52 -0700 Subject: Re: [Haskell-cafe] How do I get this done in constant mem? Yes, you should not do this in IO. That requires the entire computation to finish before the result can be used. Not really the entire computation though... whnf, no? In that example, yes. But readFile takes the entire file into a strict String before it gives you the first Char, right? (Sorry again for my misleading code simplification.) main = do let thunks :: IO [Int] thunks = (sequence . replicate (10^6) $ (randomRIO (0,10^9))) putStrLn . show . head = thunks -- prints putStrLn . show . last = thunks -- overflows Meaning that the entire list needs to be kept? Is there a reason (other than it's easier to implement and it's legal :-) why the elements that have been traversed by last can't be garbage collected? -m ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] How do I get this done in constant mem?
Hi all, I think there is something about my use of the IO monad that bites me, but I am bored of staring at the code, so here you g. The code goes through a list of records and collects the maximum in each record position. -- test.hs import Random import System.Environment (getArgs) import System.IO (putStr) samples :: Int - Int - IO [[Double]] samples i j = sequence . replicate i . sequence . replicate j $ randomRIO (0, 1000 ** 3) maxima :: [[Double]] - [Double] maxima samples@(_:_) = foldr (\ x y - map (uncurry max) $ zip x y) (head samples) (tail samples) main = do args - getArgs x - samples (read (head args)) 5 putStr . (++ \n) . show $ maxima x I would expect this to take constant memory (foldr as well as foldl), but this is what happens: $ ghc -prof --make -O9 -o test test.hs [1 of 1] Compiling Main ( test.hs, test.o ) Linking test ... $ ./test 100 +RTS -p [9.881155955344708e8,9.910336352165401e8,9.71000686630374e8,9.968532576451201e8,9.996200333115692e8] $ grep 'total alloc' test.prof total alloc = 744,180 bytes (excludes profiling overheads) $ ./test 1 +RTS -p [9.996199711457872e8,9.998928358545277e8,9.99960283632381e8,9.999707142123885e8,9.998952151508758e8] $ grep 'total alloc' test.prof total alloc = 64,777,692 bytes (excludes profiling overheads) $ ./test 100 +RTS -p Stack space overflow: current size 8388608 bytes. Use `+RTS -Ksize' to increase it. $ so... does sequence somehow force the entire list of monads into evaluation before the head of the result list can be used? what can i do to implement this in constant memory? thanks! matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Network.Curl and posting XML data
Hi Erik, I am not aware of any SSL implementation in haskell either (even though I think it should go not into HTTP but into Crypto (which is a neat piece of code, but needs a lot more work)). I can think of two quick solutions if you need your Haskell code to use an SSL link: run stunnel.org and make your application connect to that, or write a Haskell wrapper around openssl.org. As for the latter, I don't know your requirements and resources so this may be possible, but from what i've seen of openssl i wouldn't want to have to do that. good luck, matthias On Wed, Oct 07, 2009 at 02:38:05PM +1100, Erik de Castro Lopo wrote: To: haskell-cafe@haskell.org From: Erik de Castro Lopo mle...@mega-nerd.com Date: Wed, 7 Oct 2009 14:38:05 +1100 Subject: Re: [Haskell-cafe] Network.Curl and posting XML data Dmitry Olshansky wrote: Hi, Erik, Did you try Network.HTTP? Is it not enough? Apparently not. Now I need to do a post to a HTTPS server and Network.HTTP does not seem to support HTTPS. Is that really right? Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Network.Curl and posting XML data
I stand corrected. The answer was 'cabal install HsOpenSSL'. On Wed, Oct 07, 2009 at 09:37:38PM +1100, Erik de Castro Lopo wrote: To: haskell-cafe@haskell.org From: Erik de Castro Lopo mle...@mega-nerd.com Date: Wed, 7 Oct 2009 21:37:38 +1100 Subject: Re: [Haskell-cafe] Network.Curl and posting XML data mf-hcafe-15c311...@etc-network.de wrote: I am not aware of any SSL implementation in haskell either (even I really find this rather surprising. Ocaml has a very decent wrapper around Openssl that works rather well so it can't be that hard. Does this mean something that has been done in Ocaml can't be tedious and/or difficult? I'm just saying that openssl has a very complex (and IMHO not very efficient) API, and that I am not at all certain whether writing a wrapper is better for your project than adding the functionality you need to Crypto. But I may be wrong. though I think it should go not into HTTP but into Crypto (which is a neat piece of code, but needs a lot more work)). But why shouldn't it should go into Network.HTTP? All I want to do is a HTTP POST of text/xml data to a HTTPS server and retrieve the text/xml data response and the HTTP response code. Whether that URL is HTTP vs HTTPS shouldn't matter. With a sane API I should just be able to change from a HTTP url to a HTTPS url and have it JustWork (tm). To have to use a different library depending on whether I'm doing http vs https is just horrible. As Magnus has pointed out (thanks), that's not what I mean. I am just saying that hacking SSL into an HTTP library is wrong, since SSL is something different. For instance, it is also commonly used for POP, IMAP, SMTP, and generic TCP tunneling. I can think of two quick solutions if you need your Haskell code to use an SSL link: run stunnel.org Sorry, thats way too cludgy for my application. and make your application connect to that, or write a Haskell wrapper around openssl.org. I've used openssl directly from C and C++ so I know its doable, but I consider openssl a real blemish on the FOSS world. agreed! There is however this: http://hackage.haskell.org/packages/archive/HsOpenSSL/0.6.5/doc/html/OpenSSL-Session.html I really should look at hackage next time I am about to claim something doesn't exist. I just assumed you already had. :) Anyway, until somebody finds the time to put all these little related libraries together, this is probably what you want to use. cheers, Matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to generate random string?
does this compile at all? i don't think i understand the first line. anyway, a few hints: - if you want to have all numbers between 0..n in your output for some n, just in random order, google for permutation. - perhaps you can generate the output in an ordered fashion first, eg. into an array, and then shuffle the list by plucking elements from it at random into a new list. - do not use unsafePerformIO. it may reduce the entropy (randomness) of the results, but even if it doesn't, the code is prettier without. good luck! if you get stuck again, just post more code. matthias On Fri, Sep 18, 2009 at 10:14:53AM -0700, Snouser wrote: To: haskell-cafe@haskell.org From: Snouser linusolean...@gmail.com Date: Fri, 18 Sep 2009 10:14:53 -0700 (PDT) Subject: Re: [Haskell-cafe] How to generate random string? Snouser wrote: I need to generate a random string from 1 to 30. This is the parts I've done so far. unikString xs | let x = unsafePerformIO (randomRIO (1,30)) elem x xs = x : unikString xs | otherwise = unikString xs How do I proceed? I need the string/list to look like this: [1,9,3,6,2] et.c with only unik numbers. Thanks! I wasnt added to the mailinglist, but now I'm. -- View this message in context: http://www.nabble.com/How-to-generate-random-string--tp25512293p25512298.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 6.3668 Best match to file #0 (nonspam.css) prob: 1. pR: 6.3668 Total features in input file: 2688 #0 (nonspam.css): features: 758386, hits: 2881904, prob: 1.00e+00, pR: 6.37 #1 (spam.css): features: 1686754, hits: 3078784, prob: 4.30e-07, pR: -6.37 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] trouble compiling Crypto-4.2.0 / trouble with cabal
Hi, Cabal is still fighting me all the time. Its latest move is to be oblivious of some of the installed packages: $ cabal unpack crypto Unpacking Crypto-4.2.0... $ cd Crypto-4.2.0/ $ runghc ./Setup.hs configure --prefix=/tmp2/ Configuring Crypto-4.2.0... Setup.hs: At least the following dependencies are missing: HUnit -any, QuickCheck -any $ ghc-pkg list | grep -i -e '\(cabal\|hunit\)' Cabal-1.6.0.3, array-0.2.0.0, base-3.0.3.1, base-4.1.0.0, HTTP-4000.0.8, HUnit-1.2.2.0, ObjectName-1.0.0.0, OpenGL-2.3.0.0, My ghc version is 6.10.4.20090719. (Perhaps I should go get myself a more stable version?) How does Cabal find its packages other than by ghc-pkg? I read the documentation, and did a quick search, but came up empty-handed. thanks, matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] [Solved] Re: trouble compiling Crypto-4.2.0 / trouble with cabal
works, thanks! (: actually, what i did in the end is this (installing everything for my user locally): runghc ./Setup.hs configure --user --prefix=/tmp2/ runghc ./Setup.hs build ... (I first did the 'cabal install crypto', but for ghc-6.10.4 that didn't work. will start debugging now.) matthias On Sun, Sep 13, 2009 at 11:26:50AM -0700, Thomas DuBuisson wrote: To: mf-hcafe-15c311...@etc-network.de Cc: haskell-cafe@haskell.org From: Thomas DuBuisson thomas.dubuis...@gmail.com Date: Sun, 13 Sep 2009 11:26:50 -0700 Subject: Re: [Haskell-cafe] trouble compiling Crypto-4.2.0 / trouble with cabal Cabal, the library you are using when manuallying running Setup.hs, assumes you are doing a global installation and will ignore locally installed libraries (iirc). If you do 'cabal install crypto', cabal-install defaults to user installs and will use the user libraries. Thomas On Sun, Sep 13, 2009 at 10:54 AM, mf-hcafe-15c311...@etc-network.de wrote: Hi, Cabal is still fighting me all the time. Its latest move is to be oblivious of some of the installed packages: $ cabal unpack crypto Unpacking Crypto-4.2.0... $ cd Crypto-4.2.0/ $ runghc ./Setup.hs configure --prefix=/tmp2/ Configuring Crypto-4.2.0... Setup.hs: At least the following dependencies are missing: HUnit -any, QuickCheck -any $ ghc-pkg list | grep -i -e '\(cabal\|hunit\)' Cabal-1.6.0.3, array-0.2.0.0, base-3.0.3.1, base-4.1.0.0, HTTP-4000.0.8, HUnit-1.2.2.0, ObjectName-1.0.0.0, OpenGL-2.3.0.0, My ghc version is 6.10.4.20090719. (Perhaps I should go get myself a more stable version?) How does Cabal find its packages other than by ghc-pkg? I read the documentation, and did a quick search, but came up empty-handed. thanks, matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 9.9721 Best match to file #0 (nonspam.css) prob: 1. pR: 9.9721 Total features in input file: 3072 #0 (nonspam.css): features: 758386, hits: 2510804, prob: 1.00e+00, pR: 9.97 #1 (spam.css): features: 1686754, hits: 2531046, prob: 1.07e-10, pR: -9.97 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Re[Haskell-cafe] [2]: memoization
On Thu, Sep 10, 2009 at 05:23:26AM -0700, staafmeister wrote: To: haskell-cafe@haskell.org From: staafmeister g.c.stave...@uu.nl Date: Thu, 10 Sep 2009 05:23:26 -0700 (PDT) Subject: Re: Re[Haskell-cafe] [2]: memoization Hi Bulat, Bulat Ziganshin-2 wrote: Hello staafmeister, Thursday, September 10, 2009, 3:54:34 PM, you wrote: What do you think about such a function? This function is a bit of refactoring -- global variable in haskell way cache = unsafePerformIO $ newIORef M.empty memo f x = unsafePerformIO$ do m - readIORef cache case M.lookup x m of Just y - return y Nothing - do let res = f x writeIORef cache $ M.insert x res m return res memo2 = curry . memo . uncurry This doesn't work and is exactly what I'm afraid the compiler is going to do. Cache needs to be associated with the function f. Otherwise one would get conflicts then make the cache object store functions together with values. cache = unsafePerformIO $ newIORef M.empty memo f x = unsafePerformIO$ do m - readIORef cache case M.lookup (mkKey f, x) m of Just y - return y Nothing - do let res = f x writeIORef cache $ M.insert (mkKey f, x) res m return res memo2 = curry . memo . uncurry This leaves mkKey. Since functions are neither Ord nor Show, you'd have to hack something together yourself. Perhaps an explicit argument to memo? memo :: (Ord a) = String - (a - b) - a - IO b memo fname f x = unsafePerformIO$ do m - readIORef cache case M.lookup (fname, x) m of Just y - return y Nothing - do let res = f x writeIORef cache $ M.insert (fname, x) res m return res there is probably a better and more elegant solution, but this should at least work. right? matthias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: ForeignFunPtr
You are right, I forgot about callbacks. freeHaskellFunPtr is only for Haskell functions packaged for usage by the foreign code. Example from the FFI specification, Section 5.4.2: type Compare = Int - Int - Bool foreign import ccall wrapper mkCompare :: Compare - IO (FunPtr Compare) If you, say, x = mkCompare () and at some point decide x is not needed in your foreign code any more, it has to be freed by hand. This is the only case in which you are allowed to use freeHaskellFunPtr. The (much less interesting) case that I was thinking about, where FunPtr is used for foreign C functions, usually requires no finalization. ForeignPtr is used for foreign objects used by Haskell. The garbage collector (gc) can decide whether the object is still in use and, if it's not, finalize it. A Haskell function wrapped in a FunPtr is used in the foreign world. Haskell gc cannot be made responsible for finalizing it. In fact, (unless the foreign world has some gc of its own) there is no way for any compiler of deciding when to finalize at all. The programmer needs to decide this by calling freeHaskellFunPtr, just like she needs to decide when to free mallocked memory in C. Does that make more sense? Please kick me again if you are still not buying it. :-) cheers, matthias On Sun, Sep 06, 2009 at 02:53:52PM -0300, Maur??cio CA wrote: To: haskell-cafe@haskell.org From: Maur??cio CA mauricio.antu...@gmail.com Date: Sun, 06 Sep 2009 14:53:52 -0300 Subject: [Haskell-cafe] Re: ForeignFunPtr Isn't freeHaskellFunPtr a required finalization procedure? Maurício the purpose of ForeignPtr is to attach a finalization procedure to the object behind the pointer. for example, you can have close called aimplicitly whenever the garbage collector finds you don't need a file handle any more. function pointers do not need finalization. We have ForeignPtr. Why isn't there a corresponding ForeignFunPtr? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 5.6531 Best match to file #0 (nonspam.css) prob: 1. pR: 5.6531 Total features in input file: 2752 #0 (nonspam.css): features: 758386, hits: 2838587, prob: 1.00e+00, pR: 5.65 #1 (spam.css): features: 1686574, hits: 3088399, prob: 2.22e-06, pR: -5.65 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ForeignFunPtr
the purpose of ForeignPtr is to attach a finalization procedure to the object behind the pointer. for example, you can have close called aimplicitly whenever the garbage collector finds you don't need a file handle any more. function pointers do not need finalization. cheers, matthias On Sat, Sep 05, 2009 at 07:51:59PM -0300, Maur??cio CA wrote: To: haskell-cafe@haskell.org From: Maur??cio CA mauricio.antu...@gmail.com Date: Sat, 05 Sep 2009 19:51:59 -0300 Subject: [Haskell-cafe] ForeignFunPtr Hi, We have ForeignPtr. Why isn't there a corresponding ForeignFunPtr? Thanks, Maurício ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 0. pR: 4.1765 Best match to file #0 (nonspam.css) prob: 0. pR: 4.1765 Total features in input file: 2256 #0 (nonspam.css): features: 758386, hits: 2818973, prob: 1.00e+00, pR: 4.18 #1 (spam.css): features: 1686574, hits: 3077879, prob: 6.66e-05, pR: -4.18 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] greencard error message
greetings, greencard is confusing me: I copied an example from the command line and was hoping to look at some generated Haskell code to understand what's going on, but got this instead: | $ cat M1.gc | module M1 where | %enum PosixError Int [EACCES, ENOENT] | $ greencard M1.gc | greencard: user error (unknown, line unknown: | Don't know how to unmarshall (int res1) | | unknown, line unknown: | Don't know how to unmarshall (int res1) | | ) (is there any live code out there that i could use as an example to study? most of the links from haskell.org/greencard are dead. anybody agree to earlier comments that greencard is obsolete? i really like it so far and would be glad to hear otherwise.) thanks, mattias ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to preload the module of my own
echo ':load ~/money/Money.hs' ~/.ghci works for me. this adds a line to the startup script that loads a file that is not in any package. if this module loads other modules, you may need to play with ':cd' in addition to ':load'. hope this helps, matthias On Fri, Sep 04, 2009 at 06:14:50PM -0700, Alexander Dunlap wrote: To: zaxis z_a...@163.com, Haskell Cafe haskell-cafe@haskell.org Cc: From: Alexander Dunlap alexander.dun...@gmail.com Date: Fri, 4 Sep 2009 18:14:50 -0700 Subject: Re: [Haskell-cafe] How to preload the module of my own On Fri, Sep 4, 2009 at 6:08 PM, zaxisz_a...@163.com wrote: I want to preload the module automatically when starting ghci. The module located in ~/work directory contains some functions i use everyday. Now i use an alias: alias ghci='ghci -i ~/money/Money.hs' which works fine. However i feel there maybe are more elegant way. thanks! If the module is part of a package you can put 'import NameOfModule' in your ~/.ghc/.ghci file. That file contains commands that are run when ghci starts. I'm not sure if you can load a module that isn't installed. Alex ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 11.8869 Best match to file #0 (nonspam.css) prob: 1. pR: 11.8869 Total features in input file: 2936 #0 (nonspam.css): features: 758386, hits: 2835097, prob: 1.00e+00, pR: 11.89 #1 (spam.css): features: 1686574, hits: 2959087, prob: 1.30e-12, pR: -11.89 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] cannot build greencard
hi, i am stuck with a linker error in greencard, and haven't found anything online, so i am addressing you for fresh ideas. as soon as i get this sorted out, i will try to turn the answer into a patch that you can consider for the next release. SYMPTOMS: greencard 3.0.3 and 3.01 do not compile with ghc-6.8 (debian lenny package) and 6.10 (darcs copy, checked out yesterday). here is what happens: 4 (0) 19:27:19 m...@yoyo:/tmp2 $ tar xvpzf greencard-3.0.3.tar.gz greencard-3.0.3/ greencard-3.0.3/ANNOUNCE greencard-3.0.3/dist/ greencard-3.0.3/dist/build/ greencard-3.0.3/dist/build/greencard/ greencard-3.0.3/dist/build/greencard/greencard-tmp/ greencard-3.0.3/dist/build/greencard/greencard-tmp/Parse.hs greencard-3.0.3/examples/ greencard-3.0.3/examples/Gdbm/ greencard-3.0.3/examples/Gdbm/diffs greencard-3.0.3/examples/Gdbm/Gdbm.gc greencard-3.0.3/examples/Gdbm/gdbmplus.h greencard-3.0.3/examples/Gdbm/Main.hs greencard-3.0.3/examples/Gdbm/Makefile greencard-3.0.3/examples/Gdbm/README greencard-3.0.3/examples/Makefile greencard-3.0.3/examples/world/ greencard-3.0.3/examples/world/Main.hs greencard-3.0.3/examples/world/Makedefs.ghc greencard-3.0.3/examples/world/Makedeps greencard-3.0.3/examples/world/Makefile.ghc-linux greencard-3.0.3/examples/world/Makefile.ghc-win32 greencard-3.0.3/examples/world/Makefile.hugs-linux greencard-3.0.3/examples/world/Makefile.hugs-win32 greencard-3.0.3/examples/world/README.txt greencard-3.0.3/examples/world/World.gc greencard-3.0.3/greencard.cabal greencard-3.0.3/INSTALL greencard-3.0.3/lib/ greencard-3.0.3/lib/Foreign/ greencard-3.0.3/lib/Foreign/GreenCard.hs greencard-3.0.3/lib/GreenCard.gc greencard-3.0.3/lib/Makefile greencard-3.0.3/lib/package.conf.in greencard-3.0.3/LICENSE greencard-3.0.3/Makefile greencard-3.0.3/README greencard-3.0.3/Setup.hs greencard-3.0.3/src/ greencard-3.0.3/src/Casm.lhs greencard-3.0.3/src/Decl.lhs greencard-3.0.3/src/DIS.lhs greencard-3.0.3/src/ErrMonad.lhs greencard-3.0.3/src/ErrorHook.c greencard-3.0.3/src/FillIn.lhs greencard-3.0.3/src/FillInMonad.lhs greencard-3.0.3/src/GCToken.lhs greencard-3.0.3/src/greencard.ghc.in greencard-3.0.3/src/greencard.hugs.in greencard-3.0.3/src/GreenCard.lhs greencard-3.0.3/src/Lex.lhs greencard-3.0.3/src/LexM.lhs greencard-3.0.3/src/ListUtils.lhs greencard-3.0.3/src/Makefile greencard-3.0.3/src/MarshallMonad.lhs greencard-3.0.3/src/Name.lhs greencard-3.0.3/src/NameSupply.lhs greencard-3.0.3/src/Package.lhs greencard-3.0.3/src/Package.lhs.in greencard-3.0.3/src/Parse.ly greencard-3.0.3/src/PrettyUtils.lhs greencard-3.0.3/src/Proc.lhs greencard-3.0.3/src/Process.lhs greencard-3.0.3/src/Target.lhs greencard-3.0.3/src/Type.lhs 5 (0) 19:27:22 m...@yoyo:/tmp2 $ cd greencard-3.0.3 6 (0) 19:27:24 m...@yoyo:/tmp2/greencard-3.0.3 $ make prefix=/tmp2/ make[1]: Entering directory `/hime/tmp2/greencard-3.0.3/src' happy Parse.ly unused terminals: 1 rm -f .depend touch .depend ghc -M -optdep-f -optdep.depend -optdep-xFiniteMap -optdep-xPretty -recomp -O -fglasgow-exts Casm.lhs DIS.lhs Decl.lhs ErrMonad.lhs FillIn.lhs FillInMonad.lhs GCToken.lhs GreenCard.lhs Lex.lhs LexM.lhs ListUtils.lhs MarshallMonad.lhs Name.lhs NameSupply.lhs Package.lhs PrettyUtils.lhs Proc.lhs Process.lhs Target.lhs Type.lhs Parse.hs make[1]: Leaving directory `/hime/tmp2/greencard-3.0.3/src' make[1]: Entering directory `/hime/tmp2/greencard-3.0.3/src' ghc -recomp -O -fglasgow-exts -c Target.lhs -o Target.o ghc -recomp -O -fglasgow-exts -c PrettyUtils.lhs -o PrettyUtils.o ghc -recomp -O -fglasgow-exts -c Casm.lhs -o Casm.o Casm.lhs:544:1: Warning: Pattern match(es) are overlapped In a case alternative: _ - ... Casm.lhs:577:1: Warning: Pattern match(es) are overlapped In a case alternative: _ - ... Casm.lhs:616:4: Warning: Pattern match(es) are overlapped In a case alternative: _ - ... Casm.lhs:631:5: Warning: Pattern match(es) are overlapped In a case alternative: _ - ... ghc -recomp -O -fglasgow-exts -c ListUtils.lhs -o ListUtils.o ghc -recomp -O -fglasgow-exts -c ErrMonad.lhs -o ErrMonad.o ghc -recomp -O -fglasgow-exts -c Name.lhs -o Name.o ghc -recomp -O -fglasgow-exts -c DIS.lhs -o DIS.o ghc -recomp -O -fglasgow-exts -c Type.lhs -o Type.o ghc -recomp -O -fglasgow-exts -c Decl.lhs -o Decl.o ghc -recomp -O -fglasgow-exts -c FillInMonad.lhs -o FillInMonad.o ghc -recomp -O -fglasgow-exts -c NameSupply.lhs -o NameSupply.o ghc -recomp -O -fglasgow-exts -c FillIn.lhs -o FillIn.o ghc -recomp -O -fglasgow-exts -c GCToken.lhs -o GCToken.o ghc -recomp -O -fglasgow-exts -c MarshallMonad.lhs -o MarshallMonad.o ghc -recomp -O -fglasgow-exts -c Proc.lhs -o Proc.o ghc -recomp -O -fglasgow-exts -c LexM.lhs -o LexM.o ghc -recomp -O -fglasgow-exts -c Lex.lhs -o Lex.o ghc -recomp -O -fglasgow-exts -Onot -c Parse.hs -o Parse.o Parse.hs:1733:1: Warning: Pattern match(es) are overlapped In a case
Solved (Was: [Haskell-cafe] cannot build greencard)
Yes, it works: $ greencard -V greencard, version 3.00 (Daniel: You were right; I made the mistake of following the instructions in the README :). Now I've finally switched to Cabal, and that did the trick. Bulat: Yes, I am aware of all the other projects, but greencard seems to be a front-end to FFI, and it looks alive enough to me right now, right?) (Btw the report-bugs-to e-mail doesn't work.) (Btw2: diff -r cabal-install-0.6.2/bootstrap.sh cabal-install-0.6.2-/bootstrap.sh 166c166 dep_pkg parsec 2\. --- dep_pkg parsec 3\. shouldn't be a problem, right?) Thanks everybody, Cheers, Matthias On Wed, Sep 02, 2009 at 11:41:34PM +0200, Daniel Fischer wrote: To: haskell-cafe@haskell.org Cc: Dan Weston weston...@imageworks.com, mf-hcafe-15c311...@etc-network.de mf-hcafe-15c311...@etc-network.de From: Daniel Fischer daniel.is.fisc...@web.de Date: Wed, 2 Sep 2009 23:41:34 +0200 Subject: Re: [Haskell-cafe] cannot build greencard Am Mittwoch 02 September 2009 23:23:47 schrieb Dan Weston: Yet strangely, the last upload was Sun Apr 19 21:42:04 UTC 2009 and hackage claims it builds without failure with ghc-6.10. And in fact it builds just fine for me, so maybe it is worth finding out why it doesn't build for you. Are you using ghc-6.10.4 and the latest version of cabal? He used make, not cabal. My guess is that the makefiles haven't been updated because we now have Cabal and cabal. Formerly, Text.PrettyPrint.HughesPJ was in base, now it's in pretty, since --make is none of the HC_OPTIONS in the makefiles, ghc can't find HughesPJ, thus the linker errors. ** ACCEPT: CRM114 PASS osb unique microgroom Matcher ** CLASSIFY succeeds; success probability: 1. pR: 11.1886 Best match to file #0 (nonspam.css) prob: 1. pR: 11.1886 Total features in input file: 2456 #0 (nonspam.css): features: 758386, hits: 2553116, prob: 1.00e+00, pR: 11.19 #1 (spam.css): features: 1686574, hits: 2754260, prob: 6.48e-12, pR: -11.19 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
