On Fri, 2008-04-18 at 13:22 -0700, Adam Smyczek wrote:
The following code is just a small wrapper around the Browser module
that adds support for multipart/form-data content type. It's more or
less a prototype but works fine for me. Looking forward to suggestions
how to improve it. Be
Independently of the rant...
On Sat, Apr 19, 2008 at 6:01 AM, Jonathan Cast
[EMAIL PROTECTED] wrote:
But why do I need to jump through these hoops for a perfectly safe
commonly desired operation?
It's called a proof obligation. Haskell is not here to stop you from
jumping through
Hi Emil,
On 4/17/08, Emil Axelsson [EMAIL PROTECTED] wrote:
Hello!
I'm trying to rewrite some FD classes to use associated types instead. The
Port class is for type structures whose leaves have the same type:
class Port p
where
type Leaf p
type Struct p
toList
Evan Laforge wrote:
To threadjack a little bit, I've been interfacing haskell with c++.
It gets awkward when the c++ structures use STL types like string and
vector. Of course those are too complex for haskell to marshal to.
What I've been doing is defining an XMarshal variant of the X c++
OK, so just for fun, I decided to try implementing a parallel merge sort
using the seq and par combinators. My plan was to generate some
psuedo-random data and time how long it takes to sort it. To try to
account for lazy evaluation, what the program actually does is this:
1. Write the input
On Sat, Apr 19, 2008 at 10:56 AM, Andrew Coppin
[EMAIL PROTECTED] wrote:
Can anybody explain any of this behaviour? I have no idea what I'm
benchmarking, but it certainly doesn't appear to be the performance of a
parallel merge sort!
It would be much easier to draw sound conclusions if you
Denis Bueno wrote:
It would be much easier to draw sound conclusions if you would post your code.
Erm... good point.
See attachments.
module Sort where
import Control.Parallel
import Control.Parallel.Strategies
split0 [] = []
split0 (x:xs) = x : split1 xs
split1 [] = []
split1 (x:xs) =
Thanks to all who helped me with my query about functional dependencies
- much appreciated. And special thanks to Bulat for reminding me
that the GHC user guide is more than just a user guide. :-)
Alexis.
___
Haskell-Cafe mailing list
Hello Andrew,
Saturday, April 19, 2008, 6:56:10 PM, you wrote:
OK, so just for fun, I decided to try implementing a parallel merge sort
coincedence - now i'm writing a parallel compression algorithm, very
much like parallel bzip2, but using ghc, of course
Weird thing #1: The first time you
I can't offer definite answers to your questions, but I can suggest a few
issues you should consider:
1. Merge sort doesn't parallelize all that well--when the blocks are
small, the parallelization overhead is large in comparison with the
productive work that is to be done, and when the
On Apr 19, 2008, at 9:56 AM, Andrew Coppin wrote:
Weird thing #3: Adding the -threaded compiler option makes
*everything* run a few percent faster. Even with only 1 OS thread.
I had a similar thing happen to me once.
Hello Andrew,
Saturday, April 19, 2008, 7:50:30 PM, you wrote:
this looks like disk caching effects. if data are read from disj on
first run and from disk cache on the next runs, this only means that
your algorithm works faster than reading its data from disk
Negative. No data is ever
Okay, here are my thoughts:
On Apr 19, 2008, at 9:56 AM, Andrew Coppin wrote:
Weird thing #1: The first time you sort the data, it takes a few
seconds. The other 7 times, it takes a split second - roughly 100x
faster. Wuh?
This looks like standard memoization to me. I know, I know, GHC
On Apr 19, 2008, at 11:50 , Andrew Coppin wrote:
Bulat Ziganshin wrote:
there are plenty of reasons: first, -threaded make i/o overlapped
with calculations.
Not with -N1.
Depending on how it's implemented (I not being a ghc guru), possibly
even with -N1 as long as it's using the
Hello Brandon,
Saturday, April 19, 2008, 8:24:03 PM, you wrote:
contention. (Note that resource locking will be done by the threaded
runtime even with only one thread, so you will see some slowdowns
especially in I/O-related code.)
yes, i forget about this. Simon wrote once that locking
you mean, you hack around with the internal representation of those
structures? Well, if you want to avoid double-copying, C++ can't access
Haskell sequences, and Haskell can't access C++ sequences, I guess I don't
see an alternative.
I don't really mind double copying, but having to
On Apr 19, 2008, at 11:53 , Murray Gross wrote:
2. You need to account for I/O buffering (not only by your OP
system in RAM, but by your disk controller)--after the first set of
I/O operations, your data may be in buffers, so subsequent uses may
retrieve data from buffers rather than from
you could write a C++ function to marshal a Sequence (or any Container
IIRC, maybe Forward Container) to a vector (or whatever you wanted --
there are choices), and then
okay let's see if I remember C++ well enough
This design has extra copying. but anyway
templatetypename Container
Dan Weston wrote:
f . and == and . map f
where f = (not x ||)
If and is defined with foldr, then the above can be proven for all
well-typed f, and for f = (not x ||) in particular, even if ys is null.
The law is painlessly extended to cover the null case automatically (and
is
David MacIver wrote:
Independently of the rant...
On Sat, Apr 19, 2008 at 6:01 AM, Jonathan Cast
[EMAIL PROTECTED] wrote:
But why do I need to jump through these hoops for a perfectly safe
commonly desired operation?
It's called a proof obligation. Haskell is not here to stop you from
vigalchin:
Hello,
In the past someone sent me a URL on how to formally publish
Haskell work for public review and consumption. Does anyone have his link?
Regards, Vasili
As usual, all answers can be found on haskell.org,
Bulat Ziganshin wrote:
Hello Brandon,
Saturday, April 19, 2008, 8:24:03 PM, you wrote:
contention. (Note that resource locking will be done by the threaded
runtime even with only one thread, so you will see some slowdowns
especially in I/O-related code.)
yes, i forget about this.
Cool message -- forward it to Simon PJ to get more info.
cdsmith:
I'm running into this in some code I wrote. What does it mean? It says
to look at -fspec-constr-count, but that flag doesn't seem to be in the
GHC documentation.
It's fairly new -- you can get explosions in the number of
Don Stewart wrote:
jsnow:
A new version of my raytracer is out...
Very impressive. Did you consider cabalising the Haskell code, so it
can be easily distributed from hackage.haskell.org?
...
-- Don
A new version is up on hackage now:
Hi all,
I wanted to use hinotify, which gives notifications on file system
changes, but found (quite naturally) that it wouldn't run on my
windows machine (since it's a binding to the linux kernel). So I
started writing a library that would give similar functionality on
Windows. This is the first
Hi,
This isn't about Haskell per se, but I was reading the old Meijer et al.
paper Functional Programming with Bananas, Lenses, Envelopes and Barbed
Wire I think there's a notational pun that's really confusing me.
On page 12 we have the CataEval equation
(|phi|) . in = phi . (|phi|)_L
Now, the
On Sat, Apr 19, 2008 at 07:37:50PM -0500, Creighton Hogg wrote:
This isn't about Haskell per se, but I was reading the old Meijer et al.
paper
Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire I
think there's a notational pun that's really confusing me.
On page 12 we
On 19 Apr 2008, at 5:02 AM, David MacIver wrote:
Independently of the rant...
On Sat, Apr 19, 2008 at 6:01 AM, Jonathan Cast
[EMAIL PROTECTED] wrote:
But why do I need to jump through these hoops for a perfectly safe
commonly desired operation?
It's called a proof obligation. Haskell is
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