RE: [Haskell-cafe] wxhaskell package for ubuntu feisty, amd64
Hi Iván, Try this: * install GHC and darcs: sudo apt-get install ghc6 sudo apt-get install darcs * install WxWidgets 2.6 sudo apt-get install libwxgtk2.6-dev sudo apt-get install freeglut3-dev sudo apt-get install g++ * install wxHaskell darcs get http://darcs.haskell.org/wxhaskell cd wxhaskell chmod u+x configure ./configure --with-opengl make sudo make install make wx sudo make wx-install cd .. * test wxhaskell with ghc ghci -package wx It's working in my laptop! Best Miguel P.S. This link could be helpful: http://wiki.loria.fr/wiki/GenI/Getting_GenI/Instructions_for_Ubuntu_Linux -Mensagem original- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Em nome de Iván Pérez Domínguez Enviada: sexta-feira, 14 de Setembro de 2007 11:36 Para: haskell-cafe@haskell.org Assunto: [Haskell-cafe] wxhaskell package for ubuntu feisty, amd64 I'm trying to install wxhaskell in ubuntu feisty, with ghc-6.6. After several days of trial and error and a few hours trying to change all types in my program to gtk2hs types, I'm tired. Does anyone have a .deb for wxhaskell that works with ghc-6.6? ___ 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] compiler implementation details
Hi, Im curious about how the Haskell compilers nowadays take care of a simple function definition like append append [] l = l append (h:t) l = h: (append t l) Do they take a rewriting way like append [1,2] [3,4] ==> 1: (append [2] [3,4]) ==> 1: (2 : (append [] [3,4]) ) ==> 1 : (2: [3,4]) ==> [1,2,3,4] Or do they converte the append definintion to some lambda-calculus flavour language append = Y (\f -> \l1 l2 -> case l1 of [] -> l2 (h:t) -> h: (f t l2)) And then apply this converted definition to the arguments? Best Miguel ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Module dependency graph generator
Take a look to HaSlicer (http://labdotnet.di.uminho.pt/HaSlicer/HaSlicer.aspx). It can do that. Best Miguel Vilaça -Mensagem original- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Em nome de Alfonso Acosta Enviada: sexta-feira, 18 de Maio de 2007 12:11 Para: Haskell-cafe Assunto: [Haskell-cafe] Module dependency graph generator Hi all, I'm searching for a tool which generates a module dependency graph (a graphviz backend would be more than enough). Does anybody know a tool with such functionality? Cheers, Fons ___ 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
RE: [Haskell-cafe] built-in lists vs inductively defined list
Hi again, IMHO for what concerns to the language they only differ in syntax. They are equal up to constructor names. What could be the case is that some compiler could do some optimizations that end up with better performance in time and space when using lists. But for what people gently ask me, the optimizations are in the functions over list and not in the data structure itself. Do you know something about an implementation that does something about the data structure itself? Best Miguel Vilaça -Mensagem original- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Em nome de Tomasz Zielonka Enviada: quarta-feira, 9 de Maio de 2007 16:13 Para: Haskell Cafe Assunto: Re: [Haskell-cafe] built-in lists vs inductively defined list On Wed, May 09, 2007 at 04:11:40PM +0200, Nils Anders Danielsson wrote: > On Wed, 09 May 2007, Stefan O'Rear <[EMAIL PROTECTED]> wrote: > > > To the best of my knowledge, there are no optimizations specific to [] > > in the compiler proper. > > > > However, the standard library has a *lot* of speed hacks you will need > > to duplicate! > > Some of which are not expressible in "ordinary" Haskell (rewrite rules > used for short-cut deforestation). I just want to note that no particular compiler was named so far in this thread and this is a very compiler specific area. To OP: are you asking about the language or some particular implementation? Best regards Tomasz ___ 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] built-in lists vs inductively defined list
Hi, Can someone tell me if would be any difference (beside syntax) between the built-in Haskell list with [] and : and lists given by a inductive datatype definition like data List a = Nil | Cons a (List a) This is, is any of the compilers doing some special optimizations for the built-in lists? Best Miguel Vilaça ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] outputing .hs file without comments
Hi all, Is there a simple tool or command to remove all comments from a Haskell file, i.e. something that outputs the input file but without any comments on it? Best Miguel Vilaça ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] What is the best way to understand large programs?
Hi > Some sort of module dependancy graph would also be handy, but I'm not > sure any program can yet produce that kind of information. Take a look to HaSlicer (http://labdotnet.di.uminho.pt/HaSlicer/HaSlicer.aspx ) Currently it is only available online but if you want it to run locally in your machine you can email the author and ask for the source code. Best Miguel Vilaça ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] type and class problems compiling code on GHC 6.6
Dear Haskellers,
I had used some code which worked fine on GHC 6.4 and now it dont compile
on GHC 6.6.
Can anyone please give me some workarounds and/or explanations about these 2
errors?
instance InfoKind a b => InfoKind (Maybe a) b where
blank = Nothing
check n _ Nothing = ["No info value stored with "++n]
check n g (Just a) = check n g a
GHC complains that
Illegal instance declaration for `InfoKind (Maybe a) b'
(the Coverage Condition fails for one of the functional
dependencies)
In the instance declaration for `InfoKind (Maybe a) b'
multiListViewGetTSelections :: MultiListView x () -> IO [x]
multiListViewGetTSelections multiListView =
do { Just ((model, _) :: (Var [x], x -> String)) <-
unsafeObjectGetClientData multiListView
; -- more and more code
}
GHC complains that
A pattern type signature cannot bind scoped type variables `x'
unless the pattern has a rigid type context
In the pattern: (model, _) :: (Var [x], x -> String)
I would really appreciate some help.
Best regards
Miguel Vilaça
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[Haskell-cafe] different code in different platforms
Sorry. In the previous email I forgot the subject. Hi I’m having a small problem with the portability of my Haskell code. My code uses wxHaskell and the library for which this one is the Haskell interface (that is called wxWidgets) doesn’t work in the same away in Windows and Linux. Now I now which code run in Linux and in Windows but I don’t want to have to manually change the file in each platform. I tried a solution using the C pre-processor but I getting in trouble. I use code like: #ifdef __WIN32__ (Windows code) #else (Linux code) #endif I also add the --cpp to the ghc and it works for me in Linux but give me linking errors in Windows. Does someone have any hints on how to have different code in Windows and Linux? I would be thankful in some help. Best regards Miguel Vilaça ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] (no subject)
Hi I’m having a small problem with the portability of my Haskell code. My code uses wxHaskell and the library for which this one is the Haskell interface (that is called wxWidgets) doesn’t work in the same away in Windows and Linux. Now I now which code run in Linux and in Windows but I don’t want to have to manually change the file in each platform. I tried a solution using the C pre-processor but I getting in trouble. I use code like: #ifdef __WIN32__ (Windows code) #else (Linux code) #endif I also add the --cpp to the ghc and it works for me in Linux but give me linking errors in Windows. Does someone have any hints on how to have different code in Windows and Linux? I would be thankful in some help. Best regards Miguel Vilaça ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Intersection types for Haskell?
Hi
If I understand your problem than the following is a solution:
--
{-# OPTIONS -fglasgow-exts #-}
class Foo a b where
g :: a -> b
type A = {- change the following -} Int
type B = {- change the following -} Char
instance Foo A B where
g a = {- change the following -} ' '
type C = {- change the following -} Float
type D = {- change the following -} String
instance Foo C D where
g c = {- change the following -} ""
f :: (Foo a b, Foo c d) => a -> c -> (b, d)
f x y = (g x, g y)
-
Simply create a class an give instances for the wanted types.
The code above is also in a file in attachment.
cheers
José Miguel Vilaça
Departamento de Informática - Universidade do Minho
[EMAIL PROTECTED]
-Mensagem original-
De: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Em nome de Brian Hulley
Enviada: terça-feira, 10 de Janeiro de 2006 18:01
Para: Haskell-cafe
Assunto: [Haskell-cafe] Intersection types for Haskell?
Hi -
I'm wondering if there is any possiblility of getting intersection types
into Haskell. For example, at the moment there is no (proper) typing for:
f g x y = (g x, g y)
Ideally, I'd like to be able to write:
f:: (a -> b & c -> d) -> a -> c -> (b,d)
or
f :: (a -> b a) -> c -> d -> (b c, b d)
which is perhaps clearer and prevents bad types such as (Int -> String &
Int -> Char) by construction.
While it may be impossible (?) to infer such a type for f, would it be
possible to make use of such an annotation (esp since Haskell with GHC
extensions already has arbitary rank polymorphism)?
Also, as a second point, could functional dependencies in type classes be
written using a similar syntax eg instead of
class Insert t c a | c a -> t where
insert :: t -> c a -> c a
we could write:
class Insert (h (c a)) c a where
insert :: h (c a) -> c a -> c a
or
class Insert t@(h (c a)) c a where -- re-using as-pattern syntax
insert :: t -> c a -> c a
to avoid having to have a special syntax just for functional dependencies
and/or to be able to write more complicated fundeps more succinctly?
Regards,
Brian Hulley
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tep.hs
Description: Binary data
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