On 26 August 2010 15:56, michael rice nowg...@yahoo.com wrote:
From: http://en.wikibooks.org/wiki/Haskell/Applicative_Functors
=
import Control.Applicative
f :: (a - b - c)
fmap :: Functor f = (d - e) - f d - f e
fmap f :: Functor f = f a - f (b - c) --
2010/8/26 michael rice nowg...@yahoo.com
From: http://en.wikibooks.org/wiki/Haskell/Applicative_Functors
=
import Control.Applicative
f :: (a - b - c)
fmap :: Functor f = (d - e) - f d - f e
fmap f :: Functor f = f a - f (b - c) -- Identify d with a, and e
Yeah, I figured as much, but the code is copied right off the referenced page.
Michael
--- On Thu, 8/26/10, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote:
From: Ivan Lazar Miljenovic ivan.miljeno...@gmail.com
Subject: Re: [Haskell-cafe] On to applicative
To: michael rice
On 26 August 2010 16:09, michael rice nowg...@yahoo.com wrote:
Yeah, I figured as much, but the code is copied right off the referenced page.
Because as Vo Minh Thu says, it was there as a demonstration; in this
instance they were doing algebraic manipulation of the code and
corresponding type
Can you recommend an example that works?
Michael
--- On Thu, 8/26/10, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote:
From: Ivan Lazar Miljenovic ivan.miljeno...@gmail.com
Subject: Re: [Haskell-cafe] On to applicative
To: michael rice nowg...@yahoo.com
Cc: haskell-cafe@haskell.org
Date:
On 26 August 2010 16:29, michael rice nowg...@yahoo.com wrote:
Can you recommend an example that works?
An example of what?
The definitions of fmap2, etc. on that page look like they're correct.
--
Ivan Lazar Miljenovic
ivan.miljeno...@gmail.com
IvanMiljenovic.wordpress.com
OK, fmap2 works, but not fmap3. What am I not understanding?
Michael
import Control.Applicative
-- f :: (a - b - c)
-- fmap :: Functor f = (d - e) - f d - f e
sumsqr :: Int - Int - Int
sumsqr i j = i*i+j*j
-- fmap :: Functor f = f a - f (b - c) -- Identify d with a, and e with
(b - c)
On 26 August 2010 16:47, michael rice nowg...@yahoo.com wrote:
OK, fmap2 works, but not fmap3. What am I not understanding?
Michael
import Control.Applicative
-- f :: (a - b - c)
-- fmap :: Functor f = (d - e) - f d - f e
sumsqr :: Int - Int - Int
sumsqr i j = i*i+j*j
-- fmap ::
I think it works well :)
But sumsqr has type Int - Int - Int, not Int - Int - Int - Int.
I.e. it does take only two arguments while fmap3 takes a function of
three arguments.
2010/8/26 michael rice nowg...@yahoo.com
OK, fmap2 works, but not fmap3. What am I not understanding?
Michael
Hmm... it was my understanding that the example was showing how to *avoid*
having to create a lot of functions that do the same thing but have different
numbers of arguments.
From the Wiki page:
Anytime you feel the need to define different higher order functions to
accommodate for
btw, this could be helpful, if you have some time:
http://en.wikipedia.org/wiki/Cabal_(software)
http://www.haskell.org/cabal/
in there you maay find : http://www.haskell.org/cabal/FAQ.html
in which you can see ( hey !):
Hidden packages
This is indeed the case: if you want to apply your sumsqr function or
Ivan's (\ x y z - z * y + z), to some Functor (Maybe in this case),
you don't have to redefine them, or even to use fmap2 or fmap3: you
just have to use $ and *.
E.g.:
(\ a b c - a + b + c) $ Just 1 * Just 2 * Just 3
On 26 Aug 2010, at 08:01, michael rice wrote:
Hmm... it was my understanding that the example was showing how to *avoid*
having to create a lot of functions that do the same thing but have
different numbers of arguments.
From the Wiki page:
Anytime you feel the need to define
Daniel Fischer wrote:
John Lato wrote:
Heinrich Apfelmus wrote:
Do you have an example where you want chunking instead of single
character access?
I am unable to think of any examples where you want chunking for any
reason other than efficiency.
For many hashing or de/encryption
A lot of stuff to get one's head around. Was aware of liftM2, liftM3, etc., but
not liftA2, liftA3, etc.
So, the statement was true, but not the way that was shown in the example,
i.e., with fmap2, fmap3, etc., which required different functions for each of
the fmaps.
Thanks. Appreciate the
On Aug 26, 2010, at 12:34 AM, michael rice wrote:
A lot of stuff to get one's head around. Was aware of liftM2,
liftM3, etc., but not liftA2, liftA3, etc.
liftM and liftA are essentially equivalent (and are both essentially
equivalent to fmap) Same for the liftAn = liftMn functions
On Aug 26, 2010, at 1:29 AM, Alexander Solla wrote:
The other function is pure :: (a - b) - f (a - b). It takes a
function and lifts it into the functor, without applying it to
anything. In other words, given an f :: a - b,
My mistake, though if you got the rest of it, it should come as
Hi,
Is is possible to get Network.Socket.ByteString.recv to be
non-blocking (i.e. return directly even if no data is available) ?
I have tried ti use
setSocketOption sock NoDelay 1
but then I get the following error:
setSocketOption: unsupported operation (Protocol not available)
Here is
On Thu, Aug 26, 2010 at 01:29:16AM -0700, Alexander Solla wrote:
$ is flip fmap. f $ functor = fmap f functor
Just a quick correction: $ is fmap, not flip fmap.
-Brent
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Hi Thu,
On Thu, Aug 26, 2010 at 11:13 AM, Vo Minh Thu not...@gmail.com wrote:
Is is possible to get Network.Socket.ByteString.recv to be
non-blocking (i.e. return directly even if no data is available) ?
Unfortunately not.
I have tried ti use
setSocketOption sock NoDelay 1
but then I
2010/8/26 Johan Tibell johan.tib...@gmail.com:
Hi Thu,
On Thu, Aug 26, 2010 at 11:13 AM, Vo Minh Thu not...@gmail.com wrote:
Is is possible to get Network.Socket.ByteString.recv to be
non-blocking (i.e. return directly even if no data is available) ?
Unfortunately not.
I have tried ti
On Thu, Aug 26, 2010 at 1:08 PM, Vo Minh Thu not...@gmail.com wrote:
Ok, that explains also why using fcntl directly on the fd didn't work
either. So, I think I will go the FFI road and create my socket the
way I want. Do you see another way?
Not if you want a solution right now. You can
On 22/08/2010 11:41, Andrew Coppin wrote:
Ivan Lazar Miljenovic wrote:
Hackage has limited support for distro maintainers to state which
packages are available on the distribution. Last I checked, it required
distro maintainers to keep a text file somewhere up to date.
Note that not all
marlowsd:
If you look at the original Cabal design document[1], you'll see that
one of the goals of Cabal was to be the glue that lets you convert an
arbitrary Haskell library into a native package for a variety of systems
- including MSIs on Windows. Indeed, I must admit when we were
On Thursday 26 August 2010 09:04:23, Luc TAESCH wrote:
and looked at Lekah's message:
src\Main.hs:19:17:
Could not find module `Data.Map':
It is a member of the hidden package `containers-0.3.0.0'.
Perhaps you need to add `containers' to the build-depends in
your .cabal
On Thursday 26 August 2010 09:33:30, Heinrich Apfelmus wrote:
Daniel Fischer wrote:
John Lato wrote:
Heinrich Apfelmus wrote:
Do you have an example where you want chunking instead of single
character access?
I am unable to think of any examples where you want chunking for any
The HEAD now does FFI by default (Haskell 2010) so you would not have tripped
over this.
But even if you use the -XHaskell98 flag to recover Haskell-98 mode, you get
this error:
Foo.hs:9:1:
Invalid type signature: foreign export ccall foo :: CInt - CInt
Perhaps you meant to use
On Thu, Aug 26, 2010 at 5:02 AM, Don Stewart d...@galois.com wrote:
marlowsd:
If you look at the original Cabal design document[1], you'll see that
one of the goals of Cabal was to be the glue that lets you convert an
arbitrary Haskell library into a native package for a variety of systems
class (Binary p, Serialize p) = AsymCipher p where
generateKeypair :: RandomGen g = g - BitLength - Maybe ((p,p),g)
encryptAsym :: p - B.ByteString - B.ByteString
decryptAsym :: p - B.ByteString - B.ByteString
asymKeyLength :: p - BitLength
Regarding AsymCipher:
David Leimbach wrote:
It's quite practical. People are obsessed with shared library support
but I can not for the life of me figure out why.
Maybe because a simple Hello World program in Haskell becomes about 2MB
when compiled? (The equivilent C program ends up being 15KB or
something,
It does make a difference in certain cases. For a 2MB binary to be trivial
it assumes that (1) you are in a developed country (2) you are using a
landline internet connection and not going through your cell-phone company,
although this gap is closing fast.
I feel this India whenever I visit
Hi Alexander,
Didn't get to sleep till 4 AM and it took me a while to go though your post.
So far...
--- On Thu, 8/26/10, Alexander Solla a...@2piix.com wrote:
From: Alexander Solla a...@2piix.com
Subject: Re: [Haskell-cafe] On to applicative
To:
Cc: haskell-cafe Cafe haskell-cafe@haskell.org
Quoth Vo Minh Thu not...@gmail.com,
...
Ok, that explains also why using fcntl directly on the fd didn't work
either. So, I think I will go the FFI road and create my socket the
way I want.
I have been doing this with TCP STREAM sockets for some time,
for similar reasons and others, and as you
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On 8/26/10 05:13 , Vo Minh Thu wrote:
Is is possible to get Network.Socket.ByteString.recv to be
non-blocking (i.e. return directly even if no data is available) ?
What are you really trying to do?
The Haskelly solution to this is to use threads;
2010/8/26 Brandon S Allbery KF8NH allb...@ece.cmu.edu:
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On 8/26/10 05:13 , Vo Minh Thu wrote:
Is is possible to get Network.Socket.ByteString.recv to be
non-blocking (i.e. return directly even if no data is available) ?
What are you really
I think, that TypeRep type from Data.Typeable needs Ord class instance.
It is unnecessary, but is handy when needed.
My use case follows.
I try to create graph whose node and arc labels are differently typed.
So I can add Int node, Float node and link them by Conversion arc.
Right now I am
On Mon, Aug 9, 2010 at 11:47 AM, Jeff Rubard jeffrub...@gmail.com wrote:
Haskell CURRY?
Curried potatoes?
The lambda calculus?
Historical actuality?
SI!
LISP?
John McCarthy?
Etc
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On 8/26/10 10:23 , David Leimbach wrote:
Go, for example, has no shared libraries, and the runtime fits in every
binary. It does not even depend on libc. Go binaries call the system call
interface of the kernel, and the net result is that I get
On Aug 26, 2010, at 9:27 AM, michael rice wrote:
Some functions just happen to map to other functions.
$ is flip fmap. f $ functor = fmap f functor Brent
Yorgey's post noted.
map to? Take as arguments?
maps to as in outputs.
pure f * functor = f $ functor
Prelude
On Thu, Aug 26, 2010 at 11:11 AM, Brandon S Allbery KF8NH
allb...@ece.cmu.edu wrote:
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On 8/26/10 10:23 , David Leimbach wrote:
Go, for example, has no shared libraries, and the runtime fits in every
binary. It does not even depend on libc.
When I began looking into applicative, I googled haskell applicative and
grabbed the first one on the list, the wikipage. I think a better choice would
have been the Learn You a Haskell section on functors/applicative, the second
one on the list. I'm going to spend some time there but will no
So lately when I use cabal to install something get
Text/CSV.hs:1:0:
Warning: Module `Prelude' is deprecated:
You are using the old package `base' version 3.x.
Future GHC versions will not support base version 3.x. You
should update your code to
On 27 August 2010 10:17, Michael Litchard mich...@schmong.org wrote:
So lately when I use cabal to install something get
Text/CSV.hs:1:0:
Warning: Module `Prelude' is deprecated:
You are using the old package `base' version 3.x.
Future GHC versions will not
As said, this is an issue with the package maintainer who explicitly used
base 3.0 as a dependancy
I believe that base 3 is gonna be killed in ghc 6.14 iirc
On 27/08/2010 10:17 AM, Michael Litchard mich...@schmong.org wrote:
So lately when I use cabal to install something get
Text/CSV.hs:1:0:
On 27 August 2010 11:42, Mathew de Detrich dete...@gmail.com wrote:
As said, this is an issue with the package maintainer who explicitly used
base 3.0 as a dependancy
Or they have no upper bound on the version of base in their .cabal
file, so cabal-install tries to be clever and defaults to
On Thu, Aug 26, 2010 at 6:45 PM, Ivan Lazar Miljenovic
ivan.miljeno...@gmail.com wrote:
On 27 August 2010 11:42, Mathew de Detrich dete...@gmail.com wrote:
As said, this is an issue with the package maintainer who explicitly used
base 3.0 as a dependancy
Or they have no upper bound on the
On 27 August 2010 12:01, Jason Dagit da...@codersbase.com wrote:
I've added preference: base = 4, in my global cabal-install config and I
haven't had a single issue since. I HIGHLY recommend everyone to do this.
Ooohhh, didn't know you could put preferences and constraints in your
config file
On Aug 27, 2010, at 6:11 AM, Brandon S Allbery KF8NH wrote:
Um. That's a really good way to have all your programs stop working when
the Linux kernel interface changes yet again (ABIs? We don't need no
steenking ABIs! --- see in /usr/src/linux/Documentation). Solaris is
similar; the only
On Thu, Aug 26, 2010 at 20:51, Richard O'Keefe o...@cs.otago.ac.nz wrote:
Maybe Linux is different. One thing is NOT different, and that is
Linux upgrades *DO* reliably break programs that use dynamic linking.
Dynamic libraries get
- left out
- changed incompatibly
- moved some place
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