Sure, you can define your own type class like that:
import Prelude hiding ((+), (-)) -- usual (+) and (-) shouldn't be here...
import qualified Prelude as P -- but they still are accessible with a prefix
class Group a where
(+) :: a -> a -> a
(-) :: a -> a -> a
instance Group Integer where
On 18.11.10 21:28, c8h10n4o2 wrote:
> There's a tutorial on how to use qtDesigner with qtHaskell ?
sorry, i don't know of any tutorial, but there are some examples in the
`examples' directory of the source distribution (e.g. tetrix.hs). basically you
load the ui file, retrieve named widgets and at
The next haskell meeting in Berlin will be this wednesday:
Date: Wednesday, November 24th
Time: from 20:00
Location: c-base, Rungestrasse 20, 10179 Berlin
Hope to see you there,
Sönke
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.has
On 18 November 2010 20:28, c8h10n4o2 wrote:
>
> Or how to use XRC files with wxHaskell?
>
There are sample files in the wxHaskell distribution. If you can wait a day
or two I will have a step-by-step blog article, but it's not quite finished
yet.
Regards
Jeremy
> --
> View this message in con
On 2010-11-21 08:24 +, Malcolm Wallace wrote:
> If the list were to add a "Reply-To:" header, but only in the case
> where one was not already present, that would seem to me to be ideal.
> (None of the internet polemics against Reply-To that I have seen, have
> considered this modest sug
Hello.
I am looking for some examples of code using Text.HTML.TagSoup.Parsec,
from the tagsoup-parsec package.
Romildo
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Hi,
I've tried to simplify as much as possible my problem. Finally, I think
I can resume it like that:
Suppose these following data types :
data Rec a r = Rec a r
data RecNil = RecNil
data Wrapper a = Wrapper a
Then, we can build the following type:
type TTest = Rec Int (Rec String RecNil)
o
On Mon, Nov 22, 2010 at 02:20:22PM -0200, José Romildo Malaquias wrote:
>
> I am looking for some examples of code using Text.HTML.TagSoup.Parsec,
> from the tagsoup-parsec package.
In an attempt to learn how to use tagsoup together with parsec in order
to do web scrapping, I rewrote the applicat
Hello cafe,
When I want to locally install my own package through "cabal install" it
tries to reinstall dependencies convertible-1.0.9.1, HDBC-2.2.6.1 and
HDBC-mysql-0.6.3 even though they are already installed (and work fine).
Why does it do this?
cabal-install version 0.8.2
using version 1
On 23 November 2010 08:26, Martijn van Steenbergen
wrote:
> Hello cafe,
>
> When I want to locally install my own package through "cabal install" it
> tries to reinstall dependencies convertible-1.0.9.1, HDBC-2.2.6.1 and
> HDBC-mysql-0.6.3 even though they are already installed (and work fine). Wh
Sure, it's possible with TypeFamilies. The following compiles OK:
{-# LANGUAGE TypeFamilies #-}
module TypeCalc where
data Rec a r = Rec a r
data RecNil = RecNil
data Wrapper a = Wrapper a
class TypeList t where
type Wrapped t
i :: t -> Wrapped t
instance TypeList RecNil where
type Wrappe
Haskell does not play as well with overloading as one would do it in C++;
every
name used must be fully qualified. Indeed, if we try something like
Indeed, if we try something like
data A = A Int deriving (Show, Eq)
test = A 3 unA (A i) = i
class Group a where (+) :: a -> a -> a
instance Grou
Dear cafe,
Following the instructions at
http://matt.freels.name/2010/hdbc-mysql-os-x.html I successfully
installed HDBC-mysql on my Mac!
However when doing a "cabal install" in a local package which depends on
HDBC-mysql, cabal proceeds to reinstall HDBC-mysql (is this a bug? see
my other
On Sun, 2010-11-21 at 08:24 +, Malcolm Wallace wrote:
> > If the mailing list replaced Reply-To header it would required
> > additional effort for responders instead of just pressing reply-to-
> > all.
>
> If the list were to add a "Reply-To:" header, but only in the case
> where one was no
current cabal-install (0.8.2) cannot be compiled with ghc-7.0.1 set of
boot libraries. It requires cabal 1.8.* wich fails to compile. Does
anyone worked this out ?
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listi
On Mon, Nov 22, 2010 at 4:16 PM, Permjacov Evgeniy wrote:
> current cabal-install (0.8.2) cannot be compiled with ghc-7.0.1 set of
> boot libraries. It requires cabal 1.8.* wich fails to compile. Does
> anyone worked this out ?
On some of my development environments I've been using the developmen
I get an out-of-memory error about two thirds of the way through building qtHaskell. If I start again, the remaining
modules are compiled successfully, although GHC's memory usage creeps up to about 1.5Gb by the time it's finished. Is
there a memory leak?
(Compiling on Win64 with 4Gb RAM.)
___
17 matches
Mail list logo
