[Haskell-cafe] Compiling hugs - stop on missing symbol
Hello all, I don't know if this is the right place to ask about how to compile hugs, but I'll try. :-) My machine identifies this way: Linux mymachine 2.6.14 #1 SMP Mon Oct 31 10:55:16 CET 2005 i686 athlon i386 GNU/Linux I've downloaded this SRC package of hugs: hugs98-Mar2005-patched.tar.gz Download, unpack - OK ./configure --prefix=/mnt/data/FLP --enable-timer does not complain, suggests to perform make; make install Unfortunately, make stops with this error: gcc runhugs.o server.o builtin.o char.o compiler.o errors.o evaluator.o ffi.o goal.o input.o machdep.o machine.o module.o opts.o output.o plugin.o script.o static.o storage.o strutil.o subst.o type.o version.o -lreadline -lncurses -lm -ldl -o runhugs evaluator.o(.text+0x137): In function `evaluator': /mnt/data/FLP/Downloads/hugs98-Mar2005-patched/src/evaluator.c:98: undefined reference to `updateTimers' collect2: ld returned 1 exit status make: *** [runhugs] Error 1 Well, yes, the symbol is definitely missing, as timer.c, which defines the symbol, is included in hugs.c, which is not in the list of linked files. Nevertheless, I don't think including the file manually would help. Moreover, probably configure has produced a wrong Makefile. Any suggestions how to make it work? Dusan -- Dusan Kolartel: +420 54 114 1238 UIFS FIT VUT Brno fax: +420 54 114 1270 Bozetechova 2 e-mail: [EMAIL PROTECTED] Brno 612 66 Czech Republic -- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Vector/matrix arithmetic
On Wed, 2 Nov 2005, James McNeill wrote: On http://haskell.org/hawiki/FunDeps another approach is sketched out that looks far more appealing to me. This is to create Vector and Matrix types that can use overloaded arithmetic operators. It uses functional dependencies, and the resulting syntax looks a lot like what you can do using C++ or Matlab. Recently there was a long discussion about the design of a linear algebra library. As an answer to your mail I setup an overview of such discussions and related software packages. http://haskell.org/hawiki/LinearAlgebra ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Compiled hugs - on overload crashes
Hello again, without the --endable-timer option, I have managed to compile hugs. Nevertheless, I was not successfull with doc. OK, I don't care about it, but anyway... I've run serveral tests. One of them is appended - for trial just type cesty (1,1) - it's a kind of state-space search implementation (horse problem) made by a student long time ago, without any optimization, for testing very good. My older hugs interpreter stops with error: ERROR - Control stack overflow GHCi stops with the same error: *** Exception: stack overflow That's OK, really, that's correct behavior after printing some results. Nevertheless, the new hugs compilation stops with this: Segmentation Fault(coredump) And that's probably not the correct end. May I do something wrong? I've thought that configure + make + make install_all_but_docs (no doc compiled) should work. Sorry for bothering if this is trivial or off topic. Regards, hoping for help, Dusan -- Dusan Kolartel: +420 54 114 1238 UIFS FIT VUT Brno fax: +420 54 114 1270 Bozetechova 2 e-mail: [EMAIL PROTECTED] Brno 612 66 Czech Republic -- - -- Bohuslav Krena (xkrena00)2 IVT 23 -- FLP - Funkcionalni a logicke programovani -- Project 1 - Kun na sachovnici -- -- Zadani: -- --- -- Ze zadaneho pole najdete cestu tak, abyste prosli vsechna pole, -- ale na zadne pole nesmite vstoupit dvakrat. -- - type Pole = (Int,Int) type Cesta = [Pole] -- Test: z pole (1,1) - Pentium II Celeron 300 MHz. --1,2,3,4 ... 1s --5 ... 2 s --6 ... 15 s --7 ... 240 s --30 ... do 30 minut neskoncil. --50, 60, 61 ... control stack overflow po nekolika vysledcich. --62, 65 ... control stack overflow ihned. -- -- Vrati seznam vyhovujicich cest. cesty :: Pole - [Cesta] cesty (s,r) | pridej (s,r) [] == [] = error cesty: Zadane vychozi pole neni na sachovnici. | otherwise = hledej [[(s,r)]] -- Test: jako cesty. -- Hleda mozne cesty. hledej :: [Cesta] - [Cesta] hledej [] = [] hledej (xs:xss) | poli xs == 25 = xs : hledej xss | otherwise = hledej ( tahni xs (hledej xss) ) -- Test: OK. -- Vygeneruje tahy na pole, ktera nejsou v dosavadni ceste. tahni :: Cesta - [Cesta] - [Cesta] tahni [] ass = ass tahni (x:xs) ass = spoj (x:xs) (tah x) ass -- Test: OK. -- Propoji seznam moznych tahu s puvodni cestou. spoj :: Cesta - Cesta - [Cesta] - [Cesta] spoj _ [] ass = ass spoj xs (y:ys) ass | unikat xs y == [] = spoj xs ys ass | otherwise = (unikat xs y) : (spoj xs ys ass) -- Test: OK. -- Pokud pole neni v ceste, pak ho pridame. unikat :: Cesta - Pole - Cesta unikat xs y | clenem xs y == 1 = [] | otherwise= y:xs -- Test: OK. -- Vrati 1, pokud je jiz pole v ceste, jinak vrati 0. clenem :: Cesta - Pole - Int clenem [] _ = 0 clenem (x:xs) y | x==y = 1 | otherwise = clenem xs y -- Test: Lze tahnout i z pole mimo sachovnici. -- Vytvori seznam poli, na kteje je mozne tahnout. tah :: Pole - [Pole] tah (s,r) = pridej (s+2,r+1) (pridej (s+2,r-1) (pridej (s+1,r+2) (pridej (s+1,r-2) (pridej (s-1,r+2) (pridej (s-1,r-2) (pridej (s-2,r+1) (pridej (s-2,r-1) []))) -- Test: OK. -- Pokud je (s,r) pole sachovnice, tak je prida do seznamu xs. pridej :: Pole - [Pole] - [Pole] pridej (s,r) xs = if ((s0) (s6) (r0) (r6)) then (s,r):xs else xs -- Test: OK. -- Zjisti pocet poli v ceste. poli :: Cesta - Int poli [] = 0 poli (x:xs) = 1 + poli xs -- 21. 12. 1998 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Compiled hugs - on overload crashes
Hello again, without the --enable-timer option, I have managed to compile hugs. Nevertheless, I was not successful with doc. OK, I don't care about it, but anyway... I've run several tests. One of them is appended - for trial just type: cesty (1,1) /(It's a kind of state-space search implementation (horse problem) made by a student long time ago, without any optimization, for testing very good.)/ My older hugs interpreter stops with error: ERROR - Control stack overflow GHCi stops with the same error: *** Exception: stack overflow That's OK, really, that's correct behavior after printing some results. Nevertheless, the new hugs compilation stops with this: Segmentation Fault(coredump) And that's probably not the correct end. May I do something wrong? I've thought that configure + make + make install_all_but_docs (no doc compiled) should work. Sorry for bothering if this is trivial or off topic. Regards, hoping for help, Dusan -- Dusan Kolartel: +420 54 114 1238 UIFS FIT VUT Brno fax: +420 54 114 1270 Bozetechova 2 e-mail: [EMAIL PROTECTED] Brno 612 66 Czech Republic -- - -- Bohuslav Krena (xkrena00)2 IVT 23 -- FLP - Funkcionalni a logicke programovani -- Project 1 - Kun na sachovnici -- -- Zadani: -- --- -- Ze zadaneho pole najdete cestu tak, abyste prosli vsechna pole, -- ale na zadne pole nesmite vstoupit dvakrat. -- - type Pole = (Int,Int) type Cesta = [Pole] -- Test: z pole (1,1) - Pentium II Celeron 300 MHz. --1,2,3,4 ... 1s --5 ... 2 s --6 ... 15 s --7 ... 240 s --30 ... do 30 minut neskoncil. --50, 60, 61 ... control stack overflow po nekolika vysledcich. --62, 65 ... control stack overflow ihned. -- -- Vrati seznam vyhovujicich cest. cesty :: Pole - [Cesta] cesty (s,r) | pridej (s,r) [] == [] = error cesty: Zadane vychozi pole neni na sachovnici. | otherwise = hledej [[(s,r)]] -- Test: jako cesty. -- Hleda mozne cesty. hledej :: [Cesta] - [Cesta] hledej [] = [] hledej (xs:xss) | poli xs == 25 = xs : hledej xss | otherwise = hledej ( tahni xs (hledej xss) ) -- Test: OK. -- Vygeneruje tahy na pole, ktera nejsou v dosavadni ceste. tahni :: Cesta - [Cesta] - [Cesta] tahni [] ass = ass tahni (x:xs) ass = spoj (x:xs) (tah x) ass -- Test: OK. -- Propoji seznam moznych tahu s puvodni cestou. spoj :: Cesta - Cesta - [Cesta] - [Cesta] spoj _ [] ass = ass spoj xs (y:ys) ass | unikat xs y == [] = spoj xs ys ass | otherwise = (unikat xs y) : (spoj xs ys ass) -- Test: OK. -- Pokud pole neni v ceste, pak ho pridame. unikat :: Cesta - Pole - Cesta unikat xs y | clenem xs y == 1 = [] | otherwise= y:xs -- Test: OK. -- Vrati 1, pokud je jiz pole v ceste, jinak vrati 0. clenem :: Cesta - Pole - Int clenem [] _ = 0 clenem (x:xs) y | x==y = 1 | otherwise = clenem xs y -- Test: Lze tahnout i z pole mimo sachovnici. -- Vytvori seznam poli, na kteje je mozne tahnout. tah :: Pole - [Pole] tah (s,r) = pridej (s+2,r+1) (pridej (s+2,r-1) (pridej (s+1,r+2) (pridej (s+1,r-2) (pridej (s-1,r+2) (pridej (s-1,r-2) (pridej (s-2,r+1) (pridej (s-2,r-1) []))) -- Test: OK. -- Pokud je (s,r) pole sachovnice, tak je prida do seznamu xs. pridej :: Pole - [Pole] - [Pole] pridej (s,r) xs = if ((s0) (s6) (r0) (r6)) then (s,r):xs else xs -- Test: OK. -- Zjisti pocet poli v ceste. poli :: Cesta - Int poli [] = 0 poli (x:xs) = 1 + poli xs -- 21. 12. 1998 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Socket finalizers
Folks, I remember a message about this recently and tried googling for it but came up empty. I'm running a bunch of poker bots from ghci and although I'm calling hClose on the socket handle, it does not seem to actually close when my bots finish. I need to exit ghci for the sockets to close. How can I tackle this problem? It's important for me that the sockets close when I call hClose . Thanks, Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Threads talking back to parent
So when should I use a STM TChan instead of a regular Chan? On Oct 31, 2005, at 10:08 PM, ChrisK wrote: Or perhaps a TChan, if that is more appropriate: http://www.haskell.org/ghc/docs/latest/html/libraries/stm/Control- Concurrent-STM-TChan.html I like the curried command idiom: I'm not sure I understand this. Are you trying to show that the same logToParent approach can be used with Chan, TChan and MVar below? do chan - newChan let logToParent = writeChan chan do tChan - newTChan let logToParentSTM = writeTChan tChan let logToParent = atomically.logToParentSTM do mVar - newEmptyMVar let logToParent = putMVar mVar Thanks, Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Socket finalizers
On Thu, Nov 03, 2005 at 05:45:10PM +, Joel Reymont wrote: I'm running a bunch of poker bots from ghci and although I'm calling hClose on the socket handle, it does not seem to actually close when my bots finish. I need to exit ghci for the sockets to close. If these are listening sockets, make sure you did 'setSocketOption socket ReuseAddr 1'. Best regards Tomasz ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Maximum number of sockets
Is there a limit on the maximum number of sockets that's possible to open in GHC? I'm concerned with Mac OSX and Windows. Thanks, Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Threads talking back to parent
Joel Reymont wrote: So when should I use a STM TChan instead of a regular Chan? On Oct 31, 2005, at 10:08 PM, ChrisK wrote: Or perhaps a TChan, if that is more appropriate: http://www.haskell.org/ghc/docs/latest/html/libraries/stm/Control- Concurrent-STM-TChan.html I like the curried command idiom: I'm not sure I understand this. Are you trying to show that the same logToParent approach can be used with Chan, TChan and MVar below? do chan - newChan let logToParent = writeChan chan do tChan - newTChan let logToParentSTM = writeTChan tChan let logToParent = atomically.logToParentSTM do mVar - newEmptyMVar let logToParent = putMVar mVar Thanks, Joel Yes, exactly. I listed several alternatives. The logToParent approach hides the actualy mechanism in use. This has 2 advantages: * You can switch the code for logToParent without messing with the child code (or type signatures!) The Chan/TChan are non-blocking while the MVar (or TMVar) would block, so this is a non-trivial difference. * The child has no reference to the data structure so the only thing it can do is write/put via logToParent. If you had passed the chan/var to the child then it could accidentally start reading from it. Which would be bad. All this is an example of the Haskell is the best imperative language saying. An OO language might need a whole class/inferance structure to support what writeChan chan accomplished by currying. -- Chris ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] handling rank 2 types
I am trying to use a rank 2 type to enforce a condition on a data
structure. For the purpose of this message, I am trying to ensure that
a list is empty (ignoring the possibility of bottom elements):
{-# OPTIONS -fglasgow-exts #-}
import Control.Monad
newtype Empty = Empty (forall a. [a])
I want a function
listToEmpty :: [v] - IO Empty
listToEmpty l = liftM Empty (mapM no l) where
no :: a - IO a'
no x = fail element found
But this gives a less polymorphic error. I think the problem is that
ghc will not instantiate the a' in IO a' as a higher-rank type
because it occurs within a type contructor. I believe this is the
restriction referred to at the end of 7.4.9[1]. If I instead write
uncheckedListToEmpty :: [v] - Empty
uncheckedListToEmpty l = Empty (map no l) where
no :: a - a'
no x = error element found
it compiles, because v' can be instantiated as forall v. Rule v, and
even pass through map with the higher-rank type.
Is there any way to make ghc accept the first definition? I found this
workaround:
newtype Any = Any { unAny :: forall a. a }
listToEmptyAny :: [v] - IO Empty
listToEmptyAny l = liftM (\l - Empty (map unAny l)) (mapM no l) where
no :: a - IO Any
no x = fail element found
But needing a newtype wrapper Empty was bad enough; do I really need one
for every intermediate result (that is inside another type constructor)
as well? I could probably define a generic family of wrappers
newtype Forall = Forall (forall a. a)
newtype Forall1 c1 = Forall1 (forall a. c1 a)
newtype Forall2 c1 c2 = Forall2 (forall a. c1 c2 a)
...
But I would still have to use them everywhere. Any other tricks?
Andrew
[1]
http://haskell.org/ghc/docs/latest/html/users_guide/type-extensions.html#universal-quantification
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[Haskell-cafe] newbie help
Hi I just started on haskell , i am using the yet another haskell tutorial by Hal Daume I wrote the following program and it dint compile. what's wrong with it module Main where import IO main = do hSetBuffering stdin LineBuffering let testList = makeList let sum = foldr (+) 0 testList putStrLn Sum is ++ show(sum) makeList = do putStrLn enter a num num - getLine let nbr = read num if nbr == 0 then do return [] else do all - makeList return (nbr : all) -- the error i get is Chasing modules from: Sum.hs Compiling Main ( Sum.hs, Sum.o ) Sum.hs:6: Couldn't match `[a]' against `IO ()' Expected type: [a] Inferred type: IO () In the application `putStrLn Sum is ' In the first argument of `(++)', namely `putStrLn Sum is ' Sum.hs:9: Couldn't match `[b]' against `IO [a]' Expected type: [b] Inferred type: IO [a] In the third argument of `foldr', namely `testList' In the definition of `sum': sum = foldr (+) 0 testList - Thanks, Abhijit Ray ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] newbie help
On 11/4/05, Abhijit Ray [EMAIL PROTECTED] wrote: I wrote the following program and it dint compile. what's wrong with it module Main where import IO main = do hSetBuffering stdin LineBuffering let testList = makeList let sum = foldr (+) 0 testList putStrLn Sum is ++ show(sum) Write either testList - makeList or sum - liftM (foldr (+) 0) testList You probably want the former form. BTW, there is a sum function in Haskell prelude. Best regards Tomasz ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] newbie help
On 04/11/05, Abhijit Ray [EMAIL PROTECTED] wrote: Hi I just started on haskell , i am using the yet another haskell tutorial by Hal Daume I wrote the following program and it dint compile. what's wrong with it module Main where import IO main = do hSetBuffering stdin LineBuffering let testList = makeList let sum = foldr (+) 0 testList putStrLn Sum is ++ show(sum) makeList = do putStrLn enter a num num - getLine let nbr = read num if nbr == 0 then do return [] else do all - makeList return (nbr : all) -- the error i get is Chasing modules from: Sum.hs Compiling Main ( Sum.hs, Sum.o ) Sum.hs:6: Couldn't match `[a]' against `IO ()' Expected type: [a] Inferred type: IO () In the application `putStrLn Sum is ' In the first argument of `(++)', namely `putStrLn Sum is ' Sum.hs:9: Couldn't match `[b]' against `IO [a]' Expected type: [b] Inferred type: IO [a] In the third argument of `foldr', namely `testList' In the definition of `sum': sum = foldr (+) 0 testList - Thanks, Abhijit Ray Hello, The first error is related to the way in which the following line parses: putStrLn Sum is ++ show(sum) which is like: (putStrLn Sum is) ++ (show sum) It's complaining that you're passing an IO action to (++). It's an easy fix, add some parens, or a well-placed ($): putStrLn $ Sum is ++ show sum The second problem arises due to not running the IO action you wanted to: main = do hSetBuffering stdin LineBuffering let testList = makeList let sum = foldr (+) 0 testList putStrLn $ Sum is ++ show sum What is the type of testList? Well, it must be the same as makeList -- what is makeList's type? The definition of makeList is in the form of a do-block which carries out an IO computation producing a list of numbers, so it's (Num a) = IO [a]. Note that this is not a list, so it's unsuitable for passing to foldr. What do we do? We run the IO action using -: main = do hSetBuffering stdin LineBuffering testList - makeList let sum = foldr (+) 0 testList putStrLn $ Sum is ++ show sum This will cause the running of main to *run* the IO action makeList, getting the result into the list testList, which now has type (Num a) = [a] (here a is going to be defaulted to Integer, since nothing says otherwise, and one needs to pick something to be able to read). Hope this helps, and good luck with Haskell :) - Cale ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] handling rank 2 types
In a type system like MLF, your original code may type check.
Let's do an experiment.
We replace the IO monad by the Id(entity) monad.
We actually replace the Id newtype also to become true type-level
identity.
So we get:
--
-- This is like your 2nd say unchecked... sample
--
fooBar :: [v] - Empty
fooBar l = Empty (map no l)
where
no :: a - a'
no x = error element found
But the problem is not about a higher-rank type occurring with a type
constructor, as you guess. It is rather about functions with classic
rank-1 types. To see this, insert $ for the application of Empty:
fooBar :: [v] - Empty
fooBar l = Empty $ (map no l)
where
no :: a - a'
no x = error element found
You get the same type error as for the original monadic code. What you
could do is define a suitably typed application operator (likewise, a
suitably typed liftM). (With MLF the various types would be admitted by
a more general type.) In the non-monadic example, we need:
-- Use app instead of ($)
app :: ((forall a. [a]) - c) - (forall b. [b]) - c app f x = f x
BTW, what operations are we supposed to perform on the content of Empty;
what's the real purpose for introducing this independent type variable
a'? Parametric polymorphism seems to suggest that we can't do much.
You can observe the length of the list. That's it, more or less. Why not
store the length directly rather than having this superficially
polymorphic list? I am a little bit lost.
You wonder how you can generally solve this sort of problem?
- You seem to spot the wrapping approach: wrap foralls and unpack at
application time. This makes particularly sense for polymorphic
*functions*.
- The other approach is to use consistently rank-2 combinators.
I probably don't get what you try to do.
Ralf
-Original Message-
From: [EMAIL PROTECTED] [mailto:haskell-cafe-
[EMAIL PROTECTED] On Behalf Of Andrew Pimlott
Sent: Thursday, November 03, 2005 8:35 PM
To: haskell-cafe@haskell.org
Subject: [Haskell-cafe] handling rank 2 types
I am trying to use a rank 2 type to enforce a condition on a data
structure. For the purpose of this message, I am trying to ensure
that a list is empty (ignoring the possibility of bottom elements):
{-# OPTIONS -fglasgow-exts #-}
import Control.Monad
newtype Empty = Empty (forall a. [a])
I want a function
listToEmpty :: [v] - IO Empty
listToEmpty l = liftM Empty (mapM no l) where
no :: a - IO a'
no x = fail element found
But this gives a less polymorphic error. I think the problem is
that ghc will not instantiate the a' in IO a' as a higher-rank
type because it occurs within a type contructor. I believe this is
the restriction referred to at the end of 7.4.9[1]. If I instead
write
uncheckedListToEmpty :: [v] - Empty uncheckedListToEmpty l = Empty
(map no l) where
no :: a - a'
no x = error element found
it compiles, because v' can be instantiated as forall v. Rule v,
and even pass through map with the higher-rank type.
Is there any way to make ghc accept the first definition? I found
this
workaround:
newtype Any = Any { unAny :: forall a. a } listToEmptyAny :: [v] -
IO Empty listToEmptyAny l = liftM (\l - Empty (map unAny l)) (mapM
no l) where
no :: a - IO Any
no x = fail element found
But needing a newtype wrapper Empty was bad enough; do I really need
one for every intermediate result (that is inside another type
constructor) as well? I could probably define a generic family of
wrappers
newtype Forall = Forall (forall a. a) newtype Forall1 c1 = Forall1
(forall a. c1 a) newtype Forall2 c1 c2 = Forall2 (forall a. c1 c2 a)
...
But I would still have to use them everywhere. Any other tricks?
Andrew
[1] http://haskell.org/ghc/docs/latest/html/users_guide/type-
extensions.html#universal-quantification
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