On Mon, 25 Jul 2011, Manfred Lotz wrote:
Hi there,
If I take example imap.hs
import System.IO
import Network.HaskellNet.IMAP
import Text.Mime
import qualified Data.ByteString.Char8 as BS
import Control.Monad
-- the next lines were changed to fit to my local imap server
imapServer =
=
Call for Participation
The 16th ACM SIGPLAN International Conference
on Functional Programming (ICFP 2011)
http://www.icfpconference.org/icfp2011/
I'll give my two cents about some design I've been thinking about. Instead
of trying to derive all instances automatically, the programmer should
explicitly tell them (so the problems about conflicting implementations
would be minimised). I attach a piece of code of what I think could be done:
I have been making programs for mathematical applications
(low-dimensional topology) in Haskell, which I find a delight to code
in. However, the execution is slow, and this seems to be because
recursively defined functions seem to be recomputed. For example
f(100) needs f(15) which needs
2011/7/26 Siddhartha Gadgil siddhartha.gad...@gmail.com:
I have been making programs for mathematical applications
(low-dimensional topology) in Haskell, which I find a delight to code
in. However, the execution is slow, and this seems to be because
recursively defined functions seem to
I was looking for a way to retain the values of a specific function in
memory. Is there some way to do this.
Maybe this helps:
http://www.haskell.org/haskellwiki/Memoization
I haven't read through it, though..
Cheers,
Simon
___
Haskell-Cafe mailing
Dear List,
I am currently trying to understand the effects
of monads in the sense of parallelisation in
Haskell.
Could somebody please explain the difference
between 'rpar' and 'par'?
I mean, what has been changed after the encapsulation
of 'par' function by Eval monad?
If you asked to
On Jul 25, 2011, at 4:55 PM, Ryan Ingram wrote:
My guess is that nobody has put forward a clear enough design that solves all
the problems. In particular, orphan instances are tricky.
Here's an example:
module Prelude where
class (Functor m, Applicative m) = Monad m where
return
On Tue, Jul 26, 2011 at 1:01 PM, Alejandro Serrano Mena
trup...@gmail.com wrote:
I'll give my two cents about some design I've been thinking about. Instead
of trying to derive all instances automatically, the programmer should
explicitly tell them (so the problems about conflicting
Forwarding to list
Original Message
Subject:Re: [Haskell-cafe] How to select last inserted record from
Table Using Database.HSQL.MySQL
Date: Tue, 26 Jul 2011 14:27:56 +0300
From: Sergiy Nazarenko nazarenko.ser...@gmail.com
To: Steffen Schuldenzucker
On Tue, 26 Jul 2011 10:17:22 +0200 (CEST)
Henning Thielemann lemm...@henning-thielemann.de wrote:
On Mon, 25 Jul 2011, Manfred Lotz wrote:
Hi there,
If I take example imap.hs
import System.IO
import Network.HaskellNet.IMAP
import Text.Mime
import qualified
2011/7/26 Burak Ekici ekcbu...@hotmail.com
what has been changed after the encapsulation
of 'par' function by Eval monad?
If you asked to compare the parallelisation via monads
with non-monadic manner of it, what could you say?
'Eval' provides some useful discipline and structure. It
Hi all,
I'm currently embarking on my first major project in Haskell, after
dabbling with it for several years, and seem to keep finding myself in
situations where I create a typeclass that seems to be some sort of
specialisation of another, more general typeclass. Given that this is
the case,
For:
instance (Ord a) = Max a where
maximum = max
The same could more simply be achieved with a function:
maximum :: Ord a = a
maximum = max
Now, you probably wanted both a base-case using max and type specific,
special cases:
instance Max Int where
maximum = 2^16
If you have both
However, I'd be curious to know if (a) There are better or more
idiomatic ways of achieving the same effect, and (b) Whether or not I
should be doing this at all; It did occur to me that this seems rather
trying to re-implement OOP-style inheritance with typeclasses, and
therefore perhaps not
Hi,
Can't find on hackage any sparse vector library. Does such thing exist?
I need efficient storage and dot product calculation for very sparse
vectors with about 10 out of 40 000 non-zero components.
One solution would be to represent Sparse Vector as Data.Map with
(component_index,
On Tue, Jul 26, 2011 at 7:46 PM, Evan Laforge qdun...@gmail.com wrote:
Could you give a specific example of the problem you're trying to solve?
Sorry, yes, that'd be useful :-)
So, the project I'm working on involves developing a simulation of a
securities market. I have a type which models an
Quoth Manfred Lotz manfred.l...@arcor.de,
...
I'm not quite sure I understand what you mean. Stack overflow comes
from this:
forM_ msgs (\x - fetch con x = print)
If I change it to:
mapM_ (\x - fetch con x = print) msgs
there is the same stack overflow.
I didn't
On Tue, Jul 26, 2011 at 1:30 PM, dokondr doko...@gmail.com wrote:
Hi,
Can't find on hackage any sparse vector library. Does such thing exist?
I need efficient storage and dot product calculation for very sparse
vectors with about 10 out of 40 000 non-zero components.
One solution would be to
On Tue, Jul 26, 2011 at 1:52 PM, Tim Cowlishaw t...@timcowlishaw.co.ukwrote:
On Tue, Jul 26, 2011 at 7:46 PM, Evan Laforge qdun...@gmail.com wrote:
Could you give a specific example of the problem you're trying to solve?
Sorry, yes, that'd be useful :-)
So, the project I'm working on
Thanks for the detailed reply and example!
Using IntMap as a vector seems to be a good idea.
In your example:
1) I would use:
dot = dot' * dot'
dot' = sum . elems . intersectionWith (*)
norm = sum . fmap (**2) . elems
instead of:
dot = sum . elems .
On Tue, 26 Jul 2011, Tim Cowlishaw wrote:
For instance, for a typeclass representing the interface that any
Order type should implement:
class Order o where
price :: o - Int
size :: o - Int
I'd like to be able to specify an Eq instance for all types of class
Order in a manner similar to
On Tue, 26 Jul 2011, Alexander Solla wrote:
Given two (IntMap Double)s a and b, I would compute the projection of a along b
as
cosineSimilarity :: IntMap Double - IntMap Double - Double
cosineSimilarity a b = (dot a b) / ((norm a) * (norm b)) where
dot = sum . elems .
On Wed, 27 Jul 2011, dokondr wrote:
In your example:
1) I would use:
dot = dot' * dot'
dot' = sum . elems . intersectionWith (*)
norm = sum . fmap (**2) . elems
instead of:
dot = sum . elems . intersectionWith (*)
norm = (**0.5) . sum . fmap (**2) .
On Tue, Jul 26, 2011 at 3:27 PM, dokondr doko...@gmail.com wrote:
Thanks for the detailed reply and example!
Using IntMap as a vector seems to be a good idea.
In your example:
1) I would use:
dot = dot' * dot'
dot' = sum . elems . intersectionWith (*)
norm = sum .
On Tue, 26 Jul 2011, Manfred Lotz wrote:
main = do
s con - connectIMAP imapServer
login con user pass
mboxes - list con
mapM print mboxes
This should be mapM_ and 'ghc -Wall' spots this problem since 6.12.
The compiler (7.04) doesn't tell me anything about it.
It seems that it is
On Tue, Jul 26, 2011 at 12:19 PM, yi huang yi.codepla...@gmail.com wrote:
Actually, i'm wondering how to do exception handling and resource cleanup
in iteratee, e.g. your `writer` iteratee, i found it difficult, because
iteratee is designed to let enumerator manage resources.
I've found the
This may sound ignorant because, well, it is ignorant: I know very
little about the underlying mechanics here.
Installing the Haskell Platform currently requires XCode developer tools.
To get XCode on my 10.6 machine, I...
[*** begin ranty details (skippable)
... was told I could get a free
On 27 July 2011 13:55, Tom Murphy amin...@gmail.com wrote:
This may sound ignorant because, well, it is ignorant: I know very
little about the underlying mechanics here.
Installing the Haskell Platform currently requires XCode developer tools.
To get XCode on my 10.6 machine, I...
My
On 7/27/11, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote:
Installing the Haskell Platform currently requires XCode developer tools.
To get XCode on my 10.6 machine, I...
My understanding is that it's about $5 (though I seem to recall
hearing that they recently made it free), but I
On 27 July 2011 14:18, Tom Murphy amin...@gmail.com wrote:
On 7/27/11, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote:
Installing the Haskell Platform currently requires XCode developer tools.
To get XCode on my 10.6 machine, I...
My understanding is that it's about $5 (though I seem
On 27/07/2011, at 4:24 PM, Ivan Lazar Miljenovic wrote:
If this is the case, couldn't the HP use gcc instead? I'd personally
advocate gcc as standard, not as a workaround, because
a) gcc is FOSS.
b) XCode is 4GB and its functionality is basically orthogonal to the
needs of Haskell
If you're using Lion you can get Xcode from the App Store (Apple used
to charge something for it, but now it is free).
If you're using Snow Leopard you can download Xcode from
developer.apple.com/xcode. See Looking for Xcode 3? Download Now in
the bottom right corner of the page. You need to
27/07/2011 3:27 PM, Maciej Wos kirjutas:
If you're using Lion you can get Xcode from the App Store (Apple used
to charge something for it, but now it is free).
If you're using Snow Leopard you can download Xcode from
developer.apple.com/xcode. See Looking for Xcode 3? Download Now in
the
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