Re: [Haskell-cafe] question regarding Data.Array.Accelerate
Nevermind, I just realised I got something mixed up. Sorry to bother you. -- View this message in context: http://haskell.1045720.n5.nabble.com/question-regarding-Data-Array-Accelerate-tp5476144p5476586.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
[Haskell-cafe] question regarding Data.Array.Accelerate
Hi, I have read the papers about the accelerate package that provides a high-level interface to nvidia's cuda library and am very intrigued. However, I have some start-up problems. Is this the right place for such questions? In particular, I'm having trouble with lifting and unlifting. From what I understood, I should be able to use unlift to get an Int from an Exp (Plain Int), but when I try, for example, (unlift . lift) (1::Int) :: Int ghci complains with No instance for (Unlift Int). I have the latest versions of accelerate (accelerate-0.9.0.1) and ghc (version 7.4.1). I think I'm missing something obvious, so if any of you could point it out to me I would be glad. Thanks, Philipp -- View this message in context: http://haskell.1045720.n5.nabble.com/question-regarding-Data-Array-Accelerate-tp5476144p5476144.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
Re: [Haskell-cafe] Poll: Do you want a mascot?
@Wolfgang Jeltsch: I'm sorry, that was indeed my intension. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Poll: Do you want a mascot?
And also: Yes! (sorry for double post) On 24 November 2011 20:51, philipp siegmantel philipp.siegman...@googlemail.com wrote: @Wolfgang Jeltsch: I'm sorry, that was indeed my intension. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] overloading show function
On 06/30/2011 02:36 PM, Holger Siegel wrote: Am 29.06.2011 um 23:50 schrieb Philipp Schneider: Hi cafe, in my program i use a monad of the following type newtype M a = M (State - (a, State)) i use the monad in two different ways. The type variable a can be a pair as in interp :: Term - Environment - M (Value,Environment) and it can be just a value as in type Environment = [(Name, Either Value (M Value))] Simple rule: Never return an environment! An environment contains local variable bindings, so no subcomputation will ever need to return its environment. I don't know anything about the language your program interprets, but I'm sure that you can rewrite function interp as interp :: Term - Environment - M Value The structure of the interpreter will become clearer and your problem will vanish. Hello Holger, I'm giving two lambda interpreters. The first one is a call by value interpreter, the second one a call by name interpreter which are described in Philip Wadler's paper The essence of functional programming page 4 and 12. Now my task is to write a lazy lambda interpreter. The exercise is more playful than serious since Wadler's call by value interpreter is, since written in lazy Haskell, already a lazy lambda interpreter. (To get true call by value one would need to force evaluations of the arguments with the seq function.) For both of Wadler's interpreters the type of the interpertation function is: interp :: Term - Environment - M Value Now to simulate lazy interpretation i need to do the following: Decide is the value I need already evaluated or is it still a computation. In the later case I need to evaluate it and save its value in the environment. This is the reason I changed the type of the interpretation function to: interp :: Term - Environment - M (Value,Environment) I appened my full interpreter. If you can find a more elegant way to save the newly interpreted values, you are more than welcome to show my how to do it. Cheers, Philipp ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] overloading show function
On 06/30/2011 08:25 PM, Philipp Schneider wrote:
On 06/30/2011 02:36 PM, Holger Siegel wrote:
Am 29.06.2011 um 23:50 schrieb Philipp Schneider:
Hi cafe,
in my program i use a monad of the following type
newtype M a = M (State - (a, State))
i use the monad in two different ways. The type variable a can be a
pair as in
interp :: Term - Environment - M (Value,Environment)
and it can be just a value as in
type Environment = [(Name, Either Value (M Value))]
Simple rule: Never return an environment!
An environment contains local variable bindings, so no subcomputation will
ever need to return its environment. I don't know anything about the
language your program interprets, but I'm sure that you can rewrite function
interp as
interp :: Term - Environment - M Value
The structure of the interpreter will become clearer and your problem will
vanish.
Hello Holger,
I'm giving two lambda interpreters. The first one is a call by value
interpreter, the second one a call by name interpreter which are
described in Philip Wadler's paper The essence of functional
programming page 4 and 12. Now my task is to write a lazy lambda
interpreter. The exercise is more playful than serious since Wadler's
call by value interpreter is, since written in lazy Haskell, already a
lazy lambda interpreter. (To get true call by value one would need to
force evaluations of the arguments with the seq function.)
For both of Wadler's interpreters the type of the interpertation
function is:
interp :: Term - Environment - M Value
Now to simulate lazy interpretation i need to do the following: Decide
is the value I need already evaluated or is it still a computation. In
the later case I need to evaluate it and save its value in the
environment. This is the reason I changed the type of the interpretation
function to:
interp :: Term - Environment - M (Value,Environment)
I appened my full interpreter. If you can find a more elegant way to
save the newly interpreted values, you are more than welcome to show my
how to do it.
Cheers,
Philipp
I forgot to add the interpreter.
{-# LANGUAGE OverlappingInstances #-}
import Prelude hiding (lookup, fail)
import Control.Monad
-- Basiswerte
data Value= WrongAd
| WrongAp
| WrongL
| Num Int
| Fun (Either Value (M Value) - M Value)
instance Show Value where
show WrongAd= wrong add
show WrongAp= wrong app
show WrongL= wrong lookup
show (Num i) = show i
show (Fun f) = function
-- Terme
data Term = Var Name
| Con Int
| Add Term Term
| Lam Name Term
| App Term Term deriving Show
-- Interpretation der Terme (Lazy evaluation)
interp :: Term - Environment - M (Value,Environment)
interp (Var x) e = lookup x e
interp (Con i) e = return (Num i,e)
interp (Add u v) e = do
(a,e) - interp u e
(b,e) - interp v e
s - add a b
return (s,e)
interp (Lam x v) e = return (Fun (\m - (interp v ((x, m):e)) = return . fst) , e)
interp (App t u) e = do
(f,e) - interp t e
a - (apply f (Right ((interp u e) = return . fst)))
return (a,e)
add :: Value - Value - M Value
add (Num i) (Num j) = tick = (\() - return (Num (i+j)))
add a b = return WrongAd
apply :: Value - Either Value (M Value) - M Value
apply (Fun k) a= tick = (\() - k a)
apply notFun a = return WrongAp
-- Umgebung
type Environment = [(Name, Either Value (M Value))]
type Name = String
lookup :: Name - Environment - M (Value,Environment)
lookup x eComplete = lookup_h x eComplete
where
lookup_h x []= return (WrongL,[])
lookup_h x e@((y,b):etl) =
if x==y then case b of
-- schon ausgewertet
Left a - return (a,e)
-- noch nicht ausgewertet (speichere den ausgewerteten Wert)
Right a - (a = (\x- return (x, (y,Left x):eComplete)))
else lookup_h x etl
-- Lazy-Interpreter zaehlt die Reduktionen (Wadler: Beispiel 9)
type State = Int
newtype M a = M (State - (a, State))
tick = M (\s - ((), s+1))
instance (Show a,Show b) = Show (M (a,b)) where
show (M f) = let ((v,_), s) = f 0 in
Value: ++ show v ++ Count: ++ show s
instance Show a = Show (M a) where
show (M f) = let (v, s) = f 0 in
Value: ++ show v ++ Count: ++ show s
instance Monad M where
return a = M (\s - (a, s))
(M m) = k = M (\s0 - let (a, s1) = m s0
(M m') = k a
in m' s1
)
fail s = error s -- wird nicht aufgerufen
-- Beispiele:
-- test :: Term - String
test t = (interp t [])
term0 = (Con 10)
term0' = (Var x)
term1 = (Add (Con 10) (Con 11))
term2 = (Lam x (Add (Var x) (Con 10)))
term3 = (App term2 (Con 11))
term4 = (Lam x (Add (Var x) (Var x)))
term5 = (App term4 term1)
term6 = (Lam x (Lam y (Add (Var x) (Var y
term7 = (App term6 (Con 10))
term8
Re: [Haskell-cafe] overloading show function
On 06/30/2011 09:49 PM, Holger Siegel wrote: Am 30.06.2011 um 20:23 schrieb Philipp Schneider: On 06/30/2011 02:36 PM, Holger Siegel wrote: Am 29.06.2011 um 23:50 schrieb Philipp Schneider: Hi cafe, in my program i use a monad of the following type newtype M a = M (State - (a, State)) i use the monad in two different ways. The type variable a can be a pair as in interp :: Term - Environment - M (Value,Environment) and it can be just a value as in type Environment = [(Name, Either Value (M Value))] Simple rule: Never return an environment! An environment contains local variable bindings, so no subcomputation will ever need to return its environment. I don't know anything about the language your program interprets, but I'm sure that you can rewrite function interp as interp :: Term - Environment - M Value The structure of the interpreter will become clearer and your problem will vanish. Hello Holger, I'm giving two lambda interpreters. The first one is a call by value interpreter, the second one a call by name interpreter which are described in Philip Wadler's paper The essence of functional programming page 4 and 12. Now my task is to write a lazy lambda interpreter. The exercise is more playful than serious since Wadler's call by value interpreter is, since written in lazy Haskell, already a lazy lambda interpreter. (To get true call by value one would need to force evaluations of the arguments with the seq function.) Hello Philipp, that's a nice exercise. For both of Wadler's interpreters the type of the interpertation function is: interp :: Term - Environment - M Value Now to simulate lazy interpretation i need to do the following: Decide is the value I need already evaluated or is it still a computation. In the later case I need to evaluate it and save its value in the environment. This is the reason I changed the type of the interpretation function to: interp :: Term - Environment - M (Value,Environment) But that won't work: After you have evaluated an entry of the environment, you store the resulting value but you throw away its updated environment. That means, you lose the results of all subcomputations instead of propagating them to all other copies of the environment. Consider the following expression: let x = big_computation in let y = x in y + x First, big_computation is bound to the name x, resulting in an environment [(x, big_computation)]. Then a closure consisting of this environment together with the right hand side 'x' is bound to the name y. Now y+x is evaluated: The closure is entered, and from its environment the content of x - a call to big_computation - is looked up. Now big_computation is evaluated and the result is bound to x in this environment. After that, this result is also returned as the value of y. But when returning from the evaluation of y, the environment with the updated value of x is lost and you have to re-evaluate it in order to calculate x+y! Hello Holger, Can you give me an example of a lambda term in which this would be an issue? Evaluating the following works just fine in my implementation. interp (App (Lam x (Add (Var x) (Var x))) big_computation) [] When the first variable x is evaluated my interp function returns the value and the updated environment. Then to evaluate the second variable the value is just looked up from this environment. Of course in the following big_computation would be evaluated twice (App (Lam x (App (Lam y (Add (Var x) (Var y))) big_computation)) big_computation) But i simply don't have a concept like let x=y. And that is why I say never return an environment. It is either wrong or unnecessary or the resulting semantics of the interpreter is hard to comprehend. In order to implement lazy evaluation correctly, you have to maintain some global state in which the thunks are updated. For example, your environment could bind IORefs that contain unevaluated thunks to variable names and update them when the thunk is evaluated. But then your interpreter has to run in the IO monad. I agree that this would be the proper way to do it, but I was trying to minimize the use of monads since they have just been introduced in the course. By the way, do you already know Peter Sestoft's paper Deriving a lazy abstract machine? I haven't read is so far, but thanks for pointing it out. Cheers, Holger Cheers, Philipp ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] overloading show function
On 06/30/2011 11:46 PM, Holger Siegel wrote: Am 30.06.2011 um 22:57 schrieb Philipp Schneider: On 06/30/2011 09:49 PM, Holger Siegel wrote: (...) But that won't work: After you have evaluated an entry of the environment, you store the resulting value but you throw away its updated environment. That means, you lose the results of all subcomputations instead of propagating them to all other copies of the environment. Consider the following expression: let x = big_computation in let y = x in y + x First, big_computation is bound to the name x, resulting in an environment [(x, big_computation)]. Then a closure consisting of this environment together with the right hand side 'x' is bound to the name y. Now y+x is evaluated: The closure is entered, and from its environment the content of x - a call to big_computation - is looked up. Now big_computation is evaluated and the result is bound to x in this environment. After that, this result is also returned as the value of y. But when returning from the evaluation of y, the environment with the updated value of x is lost and you have to re-evaluate it in order to calculate x+y! Hello Holger, Can you give me an example of a lambda term in which this would be an issue? Evaluating the following works just fine in my implementation. interp (App (Lam x (Add (Var x) (Var x))) big_computation) [] When the first variable x is evaluated my interp function returns the value and the updated environment. Then to evaluate the second variable the value is just looked up from this environment. Of course in the following big_computation would be evaluated twice (App (Lam x (App (Lam y (Add (Var x) (Var y))) big_computation)) big_computation) But i simply don't have a concept like let x=y. App (Lam x (App (Lam y (Add (Var y) (Var x))) (Var x ))) (Con 2) takes three reduction steps, which is correct, but App (Lam x (App (Lam y (Add (Var y) (Var x))) (Var x ))) (Add (Con 1)(Con 1)) takes five reduction steps although it should take only four. Ok, I now see the problem. Thanks for pointing it out to me. And that is why I say never return an environment. It is either wrong or unnecessary or the resulting semantics of the interpreter is hard to comprehend. In order to implement lazy evaluation correctly, you have to maintain some global state in which the thunks are updated. For example, your environment could bind IORefs that contain unevaluated thunks to variable names and update them when the thunk is evaluated. But then your interpreter has to run in the IO monad. I agree that this would be the proper way to do it, but I was trying to minimize the use of monads since they have just been introduced in the course. That shouldn't be too hard. Just change your definition of monad M to newtype M a = M (State - IO (a, State)) and define the corresponding monad instance as an exercise :) (or ask me by private mail if you like). I'll try to implement it tomorrow. Hopefully I'll succeed without your help. ;) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] overloading show function
Hi cafe, in my program i use a monad of the following type newtype M a = M (State - (a, State)) i use the monad in two different ways. The type variable a can be a pair as in interp :: Term - Environment - M (Value,Environment) and it can be just a value as in type Environment = [(Name, Either Value (M Value))] now in any case when i print the monad, i just want to print the value and never the environment. More specific i want to use somthing like the following instance (Show a,Show b) = Show (M (a,b)) where show (M f) = let ((v,_), s) = f 0 in Value: ++ show v ++ Count: ++ show s instance Show a = Show (M a) where show (M f) = let (v, s) = f 0 in Value: ++ show v ++ Count: ++ show s however this gives me the following error message: Overlapping instances for Show (M (Value, Environment)) arising from a use of `print' Matching instances: instance (Show a, Show b) = Show (M (a, b)) -- Defined at /home/phil/code/haskell/vorlesung/ue09/ue09-3c3.hs:78:10-42 instance Show a = Show (M a) -- Defined at /home/phil/code/haskell/vorlesung/ue09/ue09-3c3.hs:82:10-29 In a stmt of an interactive GHCi command: print it Any ideas how to fix it? Thanks! Philipp ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] overloading show function
Thank you very much, this worked.
On 06/30/2011 12:03 AM, aditya siram wrote:
Try enabling OverlappingInstances extension by adding this to the top
of the file:
{-# LANGUAGE OverlappingInstances #-}
-deech
On Wed, Jun 29, 2011 at 4:50 PM, Philipp Schneider
philipp.schneid...@gmx.net wrote:
Hi cafe,
in my program i use a monad of the following type
newtype M a = M (State - (a, State))
i use the monad in two different ways. The type variable a can be a
pair as in
interp :: Term - Environment - M (Value,Environment)
and it can be just a value as in
type Environment = [(Name, Either Value (M Value))]
now in any case when i print the monad, i just want to print the value
and never the environment.
More specific i want to use somthing like the following
instance (Show a,Show b) = Show (M (a,b)) where
show (M f) = let ((v,_), s) = f 0 in
Value: ++ show v ++ Count: ++ show s
instance Show a = Show (M a) where
show (M f) = let (v, s) = f 0 in
Value: ++ show v ++ Count: ++ show s
however this gives me the following error message:
Overlapping instances for Show (M (Value, Environment))
arising from a use of `print'
Matching instances:
instance (Show a, Show b) = Show (M (a, b))
-- Defined at
/home/phil/code/haskell/vorlesung/ue09/ue09-3c3.hs:78:10-42
instance Show a = Show (M a)
-- Defined at
/home/phil/code/haskell/vorlesung/ue09/ue09-3c3.hs:82:10-29
In a stmt of an interactive GHCi command: print it
Any ideas how to fix it? Thanks!
Philipp
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Re: [Haskell-cafe] Data import from octave / text file
Hi, try Numeric.Container.loadMatrix. Regards, Philipp On 15.06.2011 14:59, kaffeepause73 wrote: Hey guys, thanks for the very quick help. The code works and looks like: (any tips regards speed and memory usage ?) import System.IO import Data.Array import Data.Packed.Matrix parse :: String - [[Double]] -- expects plainer syntax parse = map (map read . words) . lines main = do -- read and show plain text text- readFile ./log.txt putStrLn text -- read and show parsed list of lists putStrLn parsed list of lists let m = parse text putStrLn (show m) -- convert to matrix and show let a = fromLists m putStrLn (show a) -- cuts out first row to get signal let t = takeColumns 1 a putStrLn (show t) putStrLn Finish -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-import-from-octave-text-file-tp4490870p4491136.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
[Haskell-cafe] Possibility to port vshaskell to VS2008?
Because my university is in the MSNDAA-program I could download the new Visual Studio 2008 Professional, what I've done today. Now I tried to install the vshaskell-extension to start learning Haskell but the installer only quits with the message that (of course) VS2005 is not installed. Now is my question if I have to download the old VS2005 or if it is somehow possible to get this extension running with VS9.0? I already tried to use the EclipseFP-plugin so I already have (win)hugs, ghc and haddoc installed (if it helps for the problem above). The problem with this plugin was that Ctrl+Space does apparently not work for code hints and because I'm just started to learn the language, I don't know every keyword... So I have to look it up everytime somewhere, I want to implement something new. The fact that Prelude.hs and others are plain text are a great help, but what I have seen in the screenshot at http://www.haskell.org/visualhaskell/screenshots.html would be much better... ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] distinguish functions from non-functions in a class/instances
oleg-7 wrote: In fact, that distinction is possible. The following article How to write an instance for not-a-function http://okmij.org/ftp/Haskell/typecast.html#is-function-type specifically describes a method of writing an instance which is selected only when the type in question is NOT a function. The method is quite general and has been extensively used (for example, to implement deep monadic join). That's really incredible, and yet I don't quite understand how IsFunction works. Here is my very short but powerful solution (nary is renamed to wrap). http://www.nabble.com/file/p14220591/wrap.hs wrap.hs -- View this message in context: http://www.nabble.com/distinguish-functions-from-non-functions-in-a-class-instances-tf4952209.html#a14220591 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
Re: [Haskell-cafe] distinguish functions from non-functions in a class/instances
Ryan Ingram wrote: No, that doesn't work; it's close, but not quite. liftM doesn't have the right type signature. liftM :: Monad m = (a - r) - (m a1 - m r) What would work is if you could define a function liftLast :: Monad m = (a0 - a1 - ... - aN - r) - (a0 - a1 - ... - aN - m r) then nary' f = runIdentity . nary (liftLast f) -- ryan I don't see a way to implement liftLast or nary for functions like (a - b - ... - r) where r is not of the form (m s). Of course one can use the Identity Monad for m, but in either case you have to modify functions like (Int - Int) to something like (Int - m Int) for a fixed type m (e.g. Identity). -- philipp n. -- View this message in context: http://www.nabble.com/distinguish-functions-from-non-functions-in-a-class-instances-tf4952209.html#a14208302 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
[Haskell-cafe] distinguish functions from non-functions in a class/instances
Hello, i'm trying to wrap functions (a - b - ... - z) of any arity to functions of type ([String] - y), where list of strings replaces the typed arguments. one attempt looks like this (here written with type families, you can replace it by functional dependencies or what ever): type family Res x type instance Res x = x type instance Res (x-y) = Res y class Nary x where nary :: x - [String] - Res x instance Nary x where nary x [] = x instance Nary (x-y) where nary f (x:xs) = nary (f $ read x) xs i hope you can get the idea. the problem is, that you cannot distinguish type (x-y) from z, so these instances are overlapping. the odd thing is. you can get this to work, if you have a terminating type as result type (for example (IO x)). then you can work with all types (IO x), (a - IO x), (a - b - IO x), ... but i don't want this delimiter IO! any ideas? greetings Philipp N. -- View this message in context: http://www.nabble.com/distinguish-functions-from-non-functions-in-a-class-instances-tf4952209.html#a14180315 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
[Haskell-cafe] Coding Standards (Coding Conventions)
I wonder if there are any Coding Standards or Coding Conventions for Haskell. Does anybody know something about it? Kind regards, Philipp Volgger ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Random idea
For me it gives: 1 + 1 Maybe you meant: . v But the rest of the commands seems working ;) Andrew Coppin schrieb: Rodrigo Queiro wrote: http://lambdabot.codersbase.com/ Wait, what the hell...? 1 + 1 /usr/lib/ghc-6.4.2/package.conf: openFile: does not exist (No such file or directory) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Problems with Hs-Plugins
I tried following very simple program: module Main where import System.Eval.Haskell main = do i - eval 1 + 6 :: Int [] :: IO (Maybe Int) if isJust i then putStrLn (show (fromJust i)) else return () I compile it with ghc -c Main.hs and everything seems fine. When I run it with ghc Main.o I get following message: Main.o(.text+0x48):fake: undefined reference to `AltDataziTypeable_zdfTypeableInt_closure' Main.o(.text+0x4d):fake: undefined reference to `SystemziEvalziHaskell_eval_closure' Main.o(.text+0x36f):fake: undefined reference to `__stginit_SystemziEvalziHaskell_' Main.o(.rodata+0x0):fake: undefined reference to `SystemziEvalziHaskell_eval_closure' Main.o(.rodata+0x4):fake: undefined reference to `AltDataziTypeable_zdfTypeableInt_closure' collect2: ld returned 1 exit status When I run it with runhaskell Main I get: GHCi runtime linker: fatal error: I found a duplicate definition for symbol _GHCziWord_fromEnum1_closure whilst processing object file c:/ghc/ghc-6-4-2/ghc-6.4.2/HSbase1.o This could be caused by: * Loading two different object files which export the same symbol * Specifying the same object file twice on the GHCi command line * An incorrect `package.conf' entry, causing some object to be loaded twice. GHCi cannot safely continue in this situation. Exiting now. Sorry. So I did probably something totally wrong, but what? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Is Hs-Plugins dead?
Is Hs-Plugins still under develeopment; is there still somebody who is updating it? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] FIT for Haskell
Who wrote FIT for Haskell on http://darcs.haskell.org/FIT/? Does anybody know if the version is stable? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] IDE support
What IDE support is available for Haskell (Visuall Haskell, EclipseFP), anything else? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Installation of hs-plugins
I now used GHC 6.4 and mingw ( MSYS-1.0.11 ). Now it is possible to configure, build and install it. But on running the test ( out of a email from the list, source code see below) it crashes again without any information. I compiled the Test1.hs with ghc -c Test1.hs. Bayley, Alistair wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Philipp Volgger could somebody please tell me how hs-plugins has to be installed. I tried it with hs-plguin 1.0rc1 and I was unable to build it. I did runhaskell Setup.lhs configure runhaskell Setup.lhs build (Crash without any information) I tried it wiht GHC 6.4, 6.4.1 and 6.6. I am using Windows XP with SP2. I'm pretty sure you need to install under some kind of bash shell. I used mingw on WinXP, but I think it can be done with cygwin. I'd recommend mingw if you don't have either installed. Note that hs-plugins doesn't work with ghc-6.6 yet on Windows, so stick with 6.4.1 if you can. Alistair * Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. * Test: module Test1 where test1 = putStrLn test1 module Main where import Prelude hiding (catch) import Control.Exception import Data.List import System.Environment import System.Plugins instance Show (LoadStatus a) where show (LoadFailure errors) = LoadFailure - ++ (concat (intersperse \n errors)) show (LoadSuccess m p) = LoadSuccess main = do a - getArgs let modName = case a of (n:_) - n _ - Test1 let modPath = ./ ++ modName ++ .o let method = test1 fc - catch (load modPath [] [] method) (\e - return (LoadFailure [Dynamic loader returned: ++ show e])) case fc of LoadFailure errors - do fail (concat (intersperse \n errors)) LoadSuccess modul proc - do let p :: IO (); p = proc proc ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Installation of hs-plugins
Hello everybody, could somebody please tell me how hs-plugins has to be installed. I tried it with hs-plguin 1.0rc1 and I was unable to build it. I did runhaskell Setup.lhs configure runhaskell Setup.lhs build (Crash without any information) I tried it wiht GHC 6.4, 6.4.1 and 6.6. I am using Windows XP with SP2. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Function call by string
Hello everybody! Can me somebody say how I can call a function by string? Thus I want to have a function that has as argument a string (name of a function to call) and then tries to call that function, a kind of: functionCall :: String - [String] - RetVal functionCall functionName arguments = ... Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Function call by string
Well, the Haskell files are not the problem, they don't have to be built automatically. The point is that I want to call functions in a Haskell function if I get their names as strings. Isn't there any possibilty to do that? Eventually the interpreter reads also the console in to execute the input. Maybe it will be the best to look there (interpreter code of GHCi) Thank you :) Lennart Augustsson schrieb: It sounds like you need to generate some kind of Haskell stubs given the Java signatures. On Apr 8, 2007, at 11:16 , Philipp Volgger wrote: Well my problem is the following. I try to make Haskell work with FIT for Java. I would like to have a 1-to-1 corresondence between the Java methods and the functions in the corresponding module in Haskell, thus they would have to have the same name and arguments/parameters. From Java I could then run the Haskell Code (by a Server), but I would like to have the possiblity to name the module, the functionname and so on. Lennart Augustsson schrieb: In general, you can't do that. You can only do it if you restrict the functions that can be called somehow, e.g., by having a list of callable functions and their names. Why do you want to do this? Perhaps there is a more Haskelly solution to your problem. -- Lennart On Apr 8, 2007, at 11:01 , Philipp Volgger wrote: Hello everybody! Can me somebody say how I can call a function by string? Thus I want to have a function that has as argument a string (name of a function to call) and then tries to call that function, a kind of: functionCall :: String - [String] - RetVal functionCall functionName arguments = ... Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
