Eugene Kirpichov wrote:
I took a toy problem - find the first node satisfying a predicate in a
binary tree, started with a naive Maybe-based implementation - and
experimented with 3 ways of changing the program:
- Church-encode the Maybe
- Convert the program into CPS
- Defunctionalize
We are organizing a Functional Programming Users Group in Singapore
and our first meeting is Monday, November 2nd at 6 pm. We will meet
initially in the Lobby of 8 Shenton Way.
Map: http://bit.ly/1PzqlB -or-
I think that we should institute an award for best documented haskell
package and yours would be my first choice.
Congratulations,
titto
2009/10/30 John Millikin jmilli...@gmail.com:
These are pure-Haskell client libraries for using the D-Bus protocol.
D-Bus is heavily used for
http://hackage.haskell.org
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Hi all,
once again I find myself merely scratching the surface of the power of
Haskell, which is exciting and frustrating at the same time.
While real world demands require me to find / develop solutions quickly
(abstractions for querying data sets) I keep catching glimpses of all this
On Sun, Nov 01, 2009 at 07:58:00AM -0600, Thomas Hartman wrote:
http://hackage.haskell.org
Hackage is down currently, I am seeding the torrent by mauke from IRC on
http://mauke.ath.cx/tmp/2009-10-19-hackage-archive.torrent
Cheers, Jochem
--
Jochem Berndsen | joc...@functor.nl |
Neat! What a cool idea.
data Solid = Solid (Vector - Bool)
With a type like this, how is it possible to make solids without hard edges?
Now the only way is to create a new primitive. In the future I want
to have blended versions of the set operations to apply fillets or
bevels at the
http://iat.ubalt.edu/summers/math/platsol.htm
and http://hyperfun.org/wiki/doku.php?id=frep:main
CSG on implicitly specified surfaces (F(r)=0) and volumes (F(r)=0).
Min(F,G) is a union, max(F,G) is an intersection.
2009/11/1 Tom Hawkins tomahawk...@gmail.com:
Neat! What a cool idea.
data
OK, I understand that now but I've got a supplimentary question.
If I put:
instance Eq b = Eq (a - b) where
(==) = liftA2 (Prelude.==)
to do the Eq part I get another error:
Couldn't match expected type `Bool'
against inferred type `a - Bool'
In the expression: liftA2
Hi
On 31 Oct 2009, at 10:39, Conor McBride wrote:
Hi
On 30 Oct 2009, at 16:14, Yusaku Hashimoto wrote:
Hello cafe,
Do you know any data-type which is Applicative but not Monad?
[can resist anything but temptation]
I have an example, perhaps not a datatype:
tomorrow-you-will-know
The type of liftA2 :: Applicative f =(a - b - c) - f a - f b - f
c. Thus, the type of liftA2 (==) :: (Eq b, Applicative f) = f b - f
b - f Bool. In your case, f :: a - b, so liftA2 (==) :: (Eq b) = (a
- b) - (a - b) - (a - Bool). (==) takes two arguments, so you're
left with the type (liftA2 (==))
On Sun, Nov 1, 2009 at 11:09 AM, b1g3ar5 nick.st...@gmail.com wrote:
OK, I understand that now but I've got a supplimentary question.
If I put:
instance Eq b = Eq (a - b) where
(==) = liftA2 (Prelude.==)
You don't need the Prelude. here.
to do the Eq part I get another error:
On Sun, Nov 1, 2009 at 7:12 AM, Heinrich Apfelmus
apfel...@quantentunnel.de wrote:
Even then, the results are mixed. The Church-encoding shines in GHCi as
it should, but loses its advantage when the code is being compiled. I
guess we have to look at the core if we want to know what exactly is
David Menendez wrote:
On Sun, Nov 1, 2009 at 7:12 AM, Heinrich Apfelmus
apfel...@quantentunnel.de wrote:
Even then, the results are mixed. The Church-encoding shines in GHCi as
it should, but loses its advantage when the code is being compiled. I
guess we have to look at the core if we want
On Tue, Oct 13, 2009 at 4:44 AM, Eugene Kirpichov ekirpic...@gmail.com wrote:
I took a toy problem - find the first node satisfying a predicate in a
binary tree, started with a naive Maybe-based implementation - and
experimented with 3 ways of changing the program:
- Church-encode the Maybe
I can confirm that, if you follow the steps on the wiki, you'll end up
with a working Mac application. Excellent work John, thanks very much!
-chris
On 30 okt 2009, at 00:53, John Velman wrote:
It's taken 21 days with interruptions, but I finally posted a
tutorial with
details of what I
This has been reported to the sysadmins.
tphyahoo:
http://hackage.haskell.org
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe
Fellow haskellers:
Haskell-mode 2.6 has been released.
* By web: http://projects.haskell.org/haskellmode-emacs/
* By darcs: http://code.haskell.org/haskellmode-emacs/
This is mainly a bugfix release; to anyone using
haskell-indentation, the big news will be that it no longer
under some
As many people guess, I am trying to port programs from Clean 1.3 to Haskell
(and also to Clean 2.2, which is easier, but not much easier). Late Professor
Wellesley wrote an interesting data base manager in Clean 1.3 that I would like
to see in Haskell and Clean 2.2. However, when I tried to
Hi Philippos,
The secret is there in the error message: seek operations on
text-moddles are not allowed on this platform
You need to set your file in to binary mode, with hSetBinaryMode
(http://haskell.org/hoogle/?hoogle=hSetBinaryMode) or openBinaryFile
For future reference, if Hackage or community is down where should
that be reported to?
On Sun, Nov 1, 2009 at 7:01 PM, Don Stewart d...@galois.com wrote:
This has been reported to the sysadmins.
tphyahoo:
http://hackage.haskell.org
___
I'd say,
community - dcoutts, Igloo, ijo...@galois.com
hackage.haskell.org/darcs.haskell.org - {dons,heinele...@galois.com
ndmitchell:
For future reference, if Hackage or community is down where should
that be reported to?
On Sun, Nov 1, 2009 at 7:01 PM,
Mark Lentczner schrieb:
My ghci installation has a very annoying behavior: When it takes input,
the result is displayed on the same line as the input, overwriting the
prompt and input. Viz.:
[1015] : ghci
GHCi, version 6.10.4: http://www.haskell.org/ghc/ :? for help
Loading
Yusaku Hashimoto schrieb:
Hello cafe,
Do you know any data-type which is Applicative but not Monad?
Here you also find an example:
http://www.haskell.org/haskellwiki/Applicative_functor
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
On Sun, Nov 1, 2009 at 8:20 PM, Svein Ove Aas svein@aas.no wrote:
Fellow haskellers:
Haskell-mode 2.6 has been released.
Make that 2.6.1. Naturally, I broke something, but I think I'm about
out of things to break now.
--
Svein Ove Aas
___
On Sun, Nov 1, 2009 at 9:44 PM, Philippos Apolinarius phi50...@yahoo.ca wrote:
To make a long story short, the program compiles, but does not run. This is
interesting, because when Clean compiles an input/output operation it
certainly executes it. In any case, what I should do in order to
On Sun, Nov 1, 2009 at 11:20 AM, Conor McBride
co...@strictlypositive.org wrote:
On 31 Oct 2009, at 10:39, Conor McBride wrote:
On 30 Oct 2009, at 16:14, Yusaku Hashimoto wrote:
Hello cafe,
Do you know any data-type which is Applicative but not Monad?
[can resist anything but temptation]
On Sun, Nov 1, 2009 at 12:31 PM, Heinrich Apfelmus
apfel...@quantentunnel.de wrote:
David Menendez wrote:
On Sun, Nov 1, 2009 at 7:12 AM, Heinrich Apfelmus
apfel...@quantentunnel.de wrote:
Even then, the results are mixed. The Church-encoding shines in GHCi as
it should, but loses its
On Nov 1, 2009, at 1:05 PM, Henning Thielemann wrote:
I had a similar problem with Haskeline and an too old version of
terminfo. I assume Haskeline is used by your GHC instead of readline.
Aha! That led me to find it: I had TERM set to 'ansi'. ghci +
Haskeline works find if TERM is set to
you saved my day!
thanks, daniel
Jochem Berndsen schrieb:
On Sun, Nov 01, 2009 at 07:58:00AM -0600, Thomas Hartman wrote:
http://hackage.haskell.org
Hackage is down currently, I am seeding the torrent by mauke from IRC on
http://mauke.ath.cx/tmp/2009-10-19-hackage-archive.torrent
Jochem Berndsen schrieb:
On Sun, Nov 01, 2009 at 07:58:00AM -0600, Thomas Hartman wrote:
http://hackage.haskell.org
Hackage is down currently, I am seeding the torrent by mauke from IRC on
http://mauke.ath.cx/tmp/2009-10-19-hackage-archive.torrent
Cool, is this the beginning of
On Sun, Nov 01, 2009 at 04:20:18PM +, Conor McBride wrote:
On 31 Oct 2009, at 10:39, Conor McBride wrote:
I have an example, perhaps not a datatype:
tomorrow-you-will-know
Elaborating, one day later,
if you know something today, you can arrange to know it tomorrow
if will know a
On Sun, Nov 1, 2009 at 8:20 PM, Svein Ove Aas svein@aas.no wrote:
Fellow haskellers:
Haskell-mode 2.6 has been released.
* By web: http://projects.haskell.org/haskellmode-emacs/
* By darcs: http://code.haskell.org/haskellmode-emacs/
Since there appears to be some confusion:
Indentation
On 2 Nov 2009, at 00:11, Ross Paterson wrote:
On Sun, Nov 01, 2009 at 04:20:18PM +, Conor McBride wrote:
On 31 Oct 2009, at 10:39, Conor McBride wrote:
I have an example, perhaps not a datatype:
tomorrow-you-will-know
Elaborating, one day later,
if you know something today, you can
I am not saying that the code has to be in OO style. When I say OO is
general, I mean I am thinking in OO style. This reflects on modeling,
program structure, even code organization.
Style is how we present things. I think that is less important than
how we think about things.
On Sun, Nov 1, 2009
After some discussion in hask...@conference.jabber.ru, I've got this ideas:
+ Distributed hackage is DHT network.
+ Everything is PGP-signed.
+ Everyone can push package into network, everyone can rate package
(malicious / SPAM / unstable / stable / etc).
+ User maintains list of trusted
+ Distributed hackage is DHT network.
A DHT has been discussed before on IRC, glad to hear more people
voicing the thought.
+ Everything is PGP-signed.
Yes, that would certainly be needed and also came up in our discussion.
+ Everyone can push package into network, everyone can rate
No no no! Why not download the normal (signed) cabal list from the
DHT (and optionally directly from hackage.haskell.org)? These are all
the packages that would appear on the website. Why serve any other
content? All nodes in the DHT may check and make sure the file (or
fragment) being
Chris Eidhof:
I'm trying to call a Haskell function from C, on OS X. There's an
excellent post [1] by Tomáš Janoušek that explains how to do this on
Linux. However, on OS X, it's different. First of all, it looks like
the -no-hs-main flag is ignored, because I get the following error:
I was correct before, except I conflated the word extended with
eliminated in my mind:
http://lambda-the-ultimate.org/node/1277#comment-51723
The most robust solution to Tim Sweeney's problem is to rethink what a
class should be:
Magicloud wrote:
I am not saying that the code has to be in OO style. When I say OO is
general, I mean I am thinking in OO style. This reflects on modeling,
program structure, even code organization.
Style is how we present things. I think that is less important than
how we think about
The style of OOP is irrelevant, and if one means by style the
conflation of the interface with the data and/or use of virtual (runtime)
base class inheritance and the style of that induces, then it is an
architectural mistake:
Opportunity cost minimization problem:
No no no! Why not download the normal (signed) cabal list from the
DHT (and optionally directly from hackage.haskell.org)? These are all
the packages that would appear on the website. Why serve any other
content? All nodes in the DHT may check and
This is an opportunity cost minimization problem:
http://www.haskell.org/pipermail/haskell-cafe/2009-November/068435.html
One of the worst (most unoptimized and conflated) solutions is to force
some determinism at the low-level language architecture specifically
targetted to achieve determinism
Thus my analysis so far is Haskell has it correct, and I am suggesting the
missing optimization is to let us automatically put an upper bound on the
space non-determinism (the topic of this thread), then the programmer can
optimize beyond that with...
Arghh, the mailing list web archive did
On Fri, 30 Oct 2009 21:38:25 -0700 (PDT), jfred...@gmail.com wrote:
... a new version of
haskell-mode for the lesser of two editors
^^
[...]
haskell-mode 2.5. Svein Ove Aas [14]announced a new version of
haskell-mode for that other 'editor'...
Untenable for many corporate users administratively prohibited from running
any P2P software. First really creative use of a DHT I've seen in 6 years,
kudos.
--Original Message--
From: Shelby Moore
Sender: haskell-cafe-boun...@haskell.org
To: haskell-cafe@haskell.org
ReplyTo:
Shelby Moore wrote:
...A type class is a polymorphic
(relative to data type) interface, and the polymorphism is strictly
parameterized for the client/consumer of the interface, i.e. the data type
is known to the function that inputs the interface AT COMPILE TIME.
...A problem with virtual
First, here it is:
primes = 2: 3: sieve 0 primes' 5
primes' = tail primes
sieve k (p:ps) x
= [x | x-[x,x+2..p*p-2], and [(x`rem`p)/=0 | p-take k primes']]
++ sieve (k+1) ps (p*p+2)
(thanks to Leon P.Smith for his brilliant idea of directly generating
the spans of odds
49 matches
Mail list logo
