On Thu, Dec 29, 2005 at 10:36:37PM +0100, Tomasz Zielonka wrote:
> On Thu, Dec 29, 2005 at 03:34:10PM -0500, Cale Gibbard wrote:
> > The issue with it taking too long seems to basically be as Joel said,
> > only one of the threads can take that MVar at a time. Even if the time
> > that it's taken i
Yes, good point. I suppose there's really no need to re-declare main once it's
been imported. Thanks!
-Original Message-
From: Remi Turk [mailto:[EMAIL PROTECTED]
Sent: Thu 12/29/2005 4:34 PM
To: Scherrer, Chad
Cc: S Koray Can; haskell-cafe@haskell.org
Subject: Re: [Haskell-cafe] RE: modu
On Dec 29, 2005, at 7:44 PM, Branimir Maksimovic wrote:
To comment some observation on this program.
Most of the pressure now is on Data.HashTable.
I've susspected such large memory usage on substring from array
conversions,
so mad version with data MyString = MakeMyStrinf { buf :: Ptr Char,
From: Isaac Gouy <[EMAIL PROTECTED]>
To: haskell-cafe@haskell.org
Subject: [Haskell-cafe] Re: Haskell Speed
Date: Thu, 29 Dec 2005 13:00:15 -0800 (PST)
--- Isaac Gouy <[EMAIL PROTECTED]> wrote:
> We'll be happy to also show a Haskell program that
> uses Data.HashTable - first, someone needs t
On Fri, Dec 16, 2005 at 07:55:50AM -0800, Scherrer, Chad wrote:
> From: S Koray Can [mailto:[EMAIL PROTECTED]
> Why not do this: name none of those modules Main.hs, and have an empty
> module Main.hs with only "import MainDeJour" and "main =
> MainDeJour.main" so you can just edit just that file.
On Dec 23, 2005, at 11:53, Arjen wrote:
On Fri, 23 Dec 2005, Joel Reymont wrote:
> Folks,
>
> I have been looking at the code for the "Arrows for invertible
> programming" paper (http://www.cs.ru.nl/A.vanWeelden/bi-arrows/) and
> I have a question about syntax. ghci surely does not like it.
>
Here's a version that provides clean output with no delays. It uses a
single-entry mailbox (the TMVar "output") to ensure the processing
doesn't run too far ahead of the log.
module Test where
import System.Random
import Control.Concurrent
import Control.Concurrent.STM
test :: IO ()
test =
do
I particularly like OCaml's provision of subtyping. As a member of
the ML family, it's module system is also quite formidable. Of course
the imperative constructs are also pretty convenient when you just
want to be quirky. But I miss the monad do-notation.
___
Also, if you are trying to display a line that looks like
insert 5
or
consume 6
then consider using
> putStrLn ("insert " ++ show r)
> putStrLn ("consume " ++ show r)
instead of
> print ("insert " ++ show r)
>
Laziness and strictness are both important depending on the situation.
I'd recommend keeping both variants around. Having to wrap values in
an extra data type just to keep laziness sort of defeats the point of
Haskell being lazy in the first place. It also makes it somewhat
awkward to use in the ca
On Thu, 2005-12-29 at 15:56 -0500, Albert Lai wrote:
. . .
> one-pass fast method, since for almost a decade no one did it. Most
> of us had to wait until someone figured it out and then we had Turbo
Judging from comments by U. Ammann [1],[2], part of the original Pascal
implementation team at
Albert Lai writes:
> For almost a decade, most (I dare claim even all) Pascal
> and C compilers were "three-pass" or "two-pass". It means
> perhaps the compiler reads the input two or three times
> [...], or perhaps the compiler reads the input once,
> produces an intermediate form and saves
On Thu, Dec 29, 2005 at 03:34:10PM -0500, Cale Gibbard wrote:
> The issue with it taking too long seems to basically be as Joel said,
> only one of the threads can take that MVar at a time. Even if the time
> that it's taken is fairly short, if one is running faster than the
> others, it tries to t
Although it's already been solved, I'd like to point out here that
foldl is (or may be) getting tail optimised, but that the stack
overflow isn't from the foldl itself, but from the evaluation of the
huge expression which that foldl builds. Evaluating the left
associative expression involves immedi
--- Isaac Gouy <[EMAIL PROTECTED]> wrote:
> We'll be happy to also show a Haskell program that
> uses Data.HashTable - first, someone needs to
> contribute that program.
Someone did: k-nucleotide Haskell GHC #2
http://shootout.alioth.debian.org/gp4/benchmark.php?test=knucleotide&lang=all
> wc :: String -> (Int, Int, Int)
> wc file = ( length (lines file)
> , length (words file)
> , length file
> )
Most people tend to think that imperative programming novices don't
even start their obvious solutions from something as inefficient as
this. Wel
Well, there's actually a more interesting problem hidden in here too.
The issue with it taking too long seems to basically be as Joel said,
only one of the threads can take that MVar at a time. Even if the time
that it's taken is fairly short, if one is running faster than the
others, it tries to
On 12/29/05, Brian Sniffen <[EMAIL PROTECTED]> wrote:
> test_Cubby => do> tv <- newTVar 0You've almost got it! But "newTVar 0" has type STM Tvar, and you'retrying to use it in the IO monad. So just say "tv <- atomically
(newTVar 0)" and you're set. Do notice that you'll see output likethis
> test_Cubby =
> do
> tv <- newTVar 0
You've almost got it! But "newTVar 0" has type STM Tvar, and you're
trying to use it in the IO monad. So just say "tv <- atomically
(newTVar 0)" and you're set. Do notice that you'll see output like
this:
co"nisnusmeer t6 "6
"
"c"oinnssuemret 61""
On 12/29/05, Quan Ta <[EMAIL PROTECTED]> wrote:
> Hello folks,
>
> Newbie question: how can I do something like the following? mixing IO and
> STM.
>
> module Test where
>
> import System.Random
> import Control.Concurrent
> import Control.Concurrent.STM
>
> test_Cubby =
> do
Change this:
>
Hello folks,
Newbie question: how can I do something like the following? mixing IO and STM.
module Test whereimport System.Random
import Control.Concurrentimport Control.Concurrent.STM
test_Cubby = do
tv <- newTVar 0
forkIO (producer tv) >> (consumer tv) where
producer tv = do r <-
On 12/29/05, Simon Peyton-Jones <[EMAIL PROTECTED]> wrote:
> Yes, it should work
> http://www.haskell.org/ghc/docs/latest/html/users_guide/sec-install-wind
> ows.html
Thanks. Sorry I missed that link, and thanks for the pointer.
Paul.
___
Haskell-Cafe m
On Dec 29, 2005, at 11:26 AM, David F. Place wrote:
Hi,
I am trying to read _Arrows, Robots, and Functional Reactive
Programming_ by Hudak, et al.
http://www.haskell.org/yampa/AFPLectureNotes.pdf
In section 2.1 there are a number of equations of the form:
g’ :: SF A C
g’ = arr g
= ar
Hi,
I am trying to read _Arrows, Robots, and Functional Reactive
Programming_ by Hudak, et al.
http://www.haskell.org/yampa/AFPLectureNotes.pdf
In section 2.1 there are a number of equations of the form:
g’ :: SF A C
g’ = arr g
= arr f1 >>> arr f2
and
i’ :: SF (A,C) (B,D)
i’ = arr i
David Roundy wrote:
> Should the Map modules have an additional Map.insertWith' that behaves
> strictly, or might it be the case that you always want strict behavior when
> using insertWith?
I think so. Once strictness is lost, there's nothing the user of a
library could do about it. If a contai
On Thu, Dec 29, 2005 at 04:24:02PM +0100, Jean-Philippe Bernardy wrote:
> On 12/29/05, David Roundy <[EMAIL PROTECTED]> wrote:
> > On Thu, Dec 29, 2005 at 01:42:29PM +0100, Christian Maeder wrote:
> > > David Roundy wrote:
> > > >>stats elems = foldl add_elem Map.empty elems
> > > >>add_elem m x =
I'd like to have GHC available to me, but some of the PCs I work on
are extremely tight on space, or "locked down" in such a way that I
can't install GHC on them. To get around this, I was considering
copying GHC from my development PC onto a pen drive, and then using
that (setting PATH when I need
Bulat Ziganshin writes:
> your BlockIO library is great, but it's usage is limited
> to very specific sutuations - when we can save pass state
> between processing of individual bytes
In my experience, any other approach to I/O is slow. If you
don't have an explicit state between processing of
On Thu, Dec 29, 2005 at 01:42:29PM +0100, Christian Maeder wrote:
> David Roundy wrote:
> >>stats elems = foldl add_elem Map.empty elems
> >>add_elem m x = Map.insertWith (+) x 1 m
> >
> >>main = print $ stats $ take 100 $ repeat 1
> >
> >This program has a space leak and runs out of stack spac
On Dec 29, 2005, at 1:23 PM, Tomasz Zielonka wrote:
- a deficiency of GHC's thread scheduler - giving too much time one
thread steals it from others (Simons, don't get angry at me - I am
probably wrong here ;-)
I would finger the scheduler, at least partially. There's no magic in
this w
On Thu, Dec 29, 2005 at 01:20:41PM +, Joel Reymont wrote:
> Why does it take a fraction of a second for 1 thread to unpickle and
> several seconds per thread for several threads to do it at the same
> time? I think this is where the mistery lies.
Have you considered any of this:
- too big
On Thu, Dec 29, 2005 at 01:02:45PM +, Adrian Hey wrote:
> I haven't followed everything that's happened on the Binary IO
> thread, but has anybody else actually tried Joels code? ..
>
> http://wagerlabs.com/timeleak.tgz
I have and I am puzzled too.
> I can reproduce the problem (ghc/Linux),
David Roundy wrote:
stats elems = foldl add_elem Map.empty elems
add_elem m x = Map.insertWith (+) x 1 m
main = print $ stats $ take 100 $ repeat 1
This program has a space leak and runs out of stack space. I'm guessing
that I'm being bit here by an unnatural amount of laziness in
Map.i
Adrian,
There's no mistery here.
Threads take a while to unpickle the large server info packet when
the gang up on it all together. By adding the MVar you are basically
installing a door in front of the packet and only letting one thread
come through.
The end result is that you are pushi
Thanks for looking, Adrian,
It'd be great if someone was able to find out more about what's going on
here. Bandwidth at GHC HQ is always tight, so the more precisely
someone can pinpoint what's happening, the faster we can fix it. Joel
has done a lot by making a repro case. Maybe others can he
Hello,
I haven't followed everything that's happened on the Binary IO
thread, but has anybody else actually tried Joels code? ..
http://wagerlabs.com/timeleak.tgz
I can reproduce the problem (ghc/Linux), but can't explain it. It
seems very strange that friggin about with an otherwise irrelevant
On Thu, Dec 29, 2005 at 11:22:11AM +0300, Bulat Ziganshin wrote:
> stack overflows AFAIK is never occur because of laziness, but only
> because your recursion is not tail-optimized.
AFAIK, evaluating a thunk in GHC-compiled code does use the stack -
update frames are being put on it.
There is a n
Hello David,
Thursday, December 29, 2005, 3:42:05 AM, you wrote:
>> stats elems = foldl add_elem Map.empty elems
DR> This program has a space leak and runs out of stack space. I'm guessing
DR> that I'm being bit here by an unnatural amount of laziness in
DR> Map.insertWith
stack overflows AFAI
Michael Benfield wrote:
I see here:
http://www.haskell.org/HOpenGL/newAPI/
OpenAL bindings listed as part of the Hierachical Libraries. And when I
download the source to a development snapshot of GHC, there they are. Is
there a way to install this on GHC 6.4?
Alternatively... I can't get GHC
I did look into this a little. There are several things going on
* GHC doesn't really expect you to use INLINE and SPECIALISE together.
INLINE says to inline a copy of the function at every call site, which
is the best possible form of specialisation, so SPECIALISE is a bit
redundant if you are h
Hello,
On Tue, 27 Dec 2005 16:39:34 +, Chris Kuklewicz wrote:
>Happy Holidays,
>I was wondering if it this small snippet of code could be altered to
>require fewer OPTIONS -fallow-... switches.
Here is a partial solution using only -fglasgow-exts:
> module MyShow where
> class MyShow t wh
| Using Haskell for this networking app forced me to focus on all the
| issues _but_ the business logic. Type constraints, binary IO and
| serialization, minimizing memory use and fighting laziness, timers,
| tweaking concurrency and setting up message channels, you name it.
That's a disappointing
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