I've been following with interest the recent discussions on reddit
about the extremely slow hash tables in Haskell compared to F# and
OCaml, and as I understood it, this performance problem is caused by
GC not liking mutable arrays
http://hackage.haskell.org/trac/ghc/ticket/650
It appears from
Brandon S. Allbery KF8NH allb...@ece.cmu.edu writes:
I wonder when we'll get a good haskell virtual package on Debian?
What would this package do?
Install ghc + all the little pieces of libghc6-cruft needed to get a
sane working environment?
Sounds easy to do (after all, it's just an empty
Today, as I was reading through The Haskell 98 Report (see
http://www.haskell.org/onlinereport/), I came across a minor typo, but
it seems that the only way to fix such typos is to report them on one
of the Haskell mailing lists; viz.:
The original committees ceased to exist when the original
[Shifted to haskell-cafe.]
G'day all.
Quoting Benjamin L.Russell dekudekup...@yahoo.com:
According to the Merriam-Webster Online Dictionary, it is topoi (see
http://www.merriam-webster.com/dictionary/topos).
Topoi form a certain class of category. You can study topous, you can
prove
On 6 Apr 2009, at 08:56, Benjamin L.Russell wrote:
Today, as I was reading through The Haskell 98 Report (see
http://www.haskell.org/onlinereport/), I came across a minor typo, but
it seems that the only way to fix such typos is to report them on one
of the Haskell mailing lists;
Thanks for
Hello FFT,
Monday, April 6, 2009, 11:07:33 AM, you wrote:
this problem addressed there? Why is this supposed to be specific to
boxed arrays only: wouldn't GC have to scan the whole mutable array
whether it's boxed or unboxed?
you need to scan only boxes: if array just contains plain
On Mon, Apr 6, 2009 at 1:10 AM, Bulat Ziganshin
bulat.zigans...@gmail.com wrote:
you need to scan only boxes: if array just contains plain cpu-level
numbers, there is nothing to scan
Are those the only legal contents of STUArray?
___
Haskell-Cafe
If I use :info (-) I get information on the binary minus. Is unary minus
also a function?
Thanks,
Paul
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
On Monday 06 April 2009 4:10:43 am Bulat Ziganshin wrote:
one way to solve this problem is to make one `modified` bit per each 256
elements rather than entire array so GC will have to scan only
modified chunks
For reference, I constructed a benchmark that takes advantage of GHC's tagging
of
If I use :info (-) I get information on the binary minus. Is unary
minus also a function?
You can define it yourself or use negate from the Prelude.
Wouter
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
Paul Keir wrote:
If I use :info (-) I get information on the binary minus. Is unary minus
also a function?
No, as far as I know the unary minus is part of the number literals. You
can use negate if you want it as a function.
Hope this helps,
Martijn.
Hello Dan,
Monday, April 6, 2009, 12:35:14 PM, you wrote:
the size of the sub-array. The test then fills a 10 million element array.
However, something about the benchmark makes it perform poorly for both small
chunks and large chunks. -sstderr reports that lots of copying occurs for
small
Hello FFT,
Monday, April 6, 2009, 12:32:53 PM, you wrote:
you need to scan only boxes: if array just contains plain cpu-level
numbers, there is nothing to scan
Are those the only legal contents of STUArray?
numbers, chars, vanilla pointers. UArray just mimics C arrays, after all
--
Best
I want the Zen package: Make me one with everything.
But would you find that on hackage?-) If an author had contemplated
the perfect package, they wouldn't have put it on hackage, they wouldn't
have a hackage account, they wouldn't have written the package, they
might not even exist - you
On Mon, 6 Apr 2009 12:13:09 +0200, Roel van Dijk
vandijk.r...@gmail.com wrote:
On Mon, Apr 6, 2009 at 12:04 PM, Benjamin L.Russell
dekudekup...@yahoo.com wrote:
Interesting. ?How is this hack implemented?
This seems to be the relevant grammar:
lexp6 - - exp7
lpat6 - - (integer | float)
On Mon, 6 Apr 2009 12:13:09 +0200, Roel van Dijk
vandijk.r...@gmail.com wrote:
On Mon, Apr 6, 2009 at 12:04 PM, Benjamin L.Russell
dekudekup...@yahoo.com wrote:
Interesting. ?How is this hack implemented?
This seems to be the relevant grammar:
lexp6 - - exp7
lpat6 - - (integer | float)
Unary minus is a hack in the syntax for allowing the function negate
to be written as prefix -.
On Mon, Apr 6, 2009 at 10:36 AM, Martijn van Steenbergen
mart...@van.steenbergen.nl wrote:
Paul Keir wrote:
If I use :info (-) I get information on the binary minus. Is unary minus
also a function?
On Mon, Apr 6, 2009 at 12:04 PM, Benjamin L.Russell
dekudekup...@yahoo.com wrote:
Interesting. How is this hack implemented?
This seems to be the relevant grammar:
lexp6 - - exp7
lpat6 - - (integer | float)(negative literal)
The '6's and the '7' are superscripts.
Perhaps the hack
Hi Thomas,
I send this e-mail because of possible scheduling issues: I will be
away starting on April 15. So, if you want to ask me things, have
suggestions for improvement, or want to do an interview or something,
this can only be done *before* that date.
I am pretty sure all the questions
Hello FFT,
Monday, April 6, 2009, 12:56:51 PM, you wrote:
Are those the only legal contents of STUArray?
numbers, chars, vanilla pointers. UArray just mimics C arrays, after all
I haven't gotten to learning about them in detail yet, but my hope was
that STUArray was like vectorT in C++,
On Mon, Apr 6, 2009 at 1:49 AM, Bulat Ziganshin
bulat.zigans...@gmail.com wrote:
Are those the only legal contents of STUArray?
numbers, chars, vanilla pointers. UArray just mimics C arrays, after all
I haven't gotten to learning about them in detail yet, but my hope was
that STUArray was
Interesting. How is this hack implemented?
I just checked the BNF grammar for the lexical syntax of Haskell in
The Haskell 98 Language Report (see the BNF grammer given under 9.2
Lexical Syntax under 9 Syntax Reference at
http://www.haskell.org/onlinereport/syntax-iso.html), but had
difficulty
Hi all,
is the paper Translating donotation to SQL, Leijden, Meijer (1999)
available anywhere?
Günther
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Considering these naming conventions:
http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Monad.html#3
• A postfix 'M' always stands for a function in the Kleisli category:
The monad type constructor m is added to function results (modulo
currying) and nowhere else. So, for
I downloaded it and it appears more complicated than just adding files to a
directory. There's a setup and a build, and no assurances it will work with
Hugs.
I think I'll wait for more information.
Michael
--- On Mon, 4/6/09, Thomas Hartman tphya...@gmail.com wrote:
From: Thomas Hartman
At Sun, 05 Apr 2009 14:32:21 +0200,
Günther Schmidt wrote:
What is the best resource to look for more detail examples?
No idea. I have not used it in years. And, last I checked, it is far
from perfect. For example, I believe that field names must be unique
across all tables.
Also, there was a
module Main where
data (:%^) a b = a :%^ bderiving (Show)
main = do
print $ 18 :%^ (Just 99)
print $ (,) 9 10
print $ 9 , 10
The last line in the code above causes a compile error.
Why does infix use of the comma (tuple constructor?) function fail
without brackets?
Am Montag 06 April 2009 17:12:42 schrieb michael rice:
I downloaded it and it appears more complicated than just adding files to a
directory. There's a setup and a build, and no assurances it will work with
Hugs.
I think I'll wait for more information.
Michael
Try installing it with Cabal:
Am Montag 06 April 2009 17:53:24 schrieb Paul Keir:
module Main where
data (:%^) a b = a :%^ bderiving (Show)
main = do
print $ 18 :%^ (Just 99)
print $ (,) 9 10
print $ 9 , 10
The last line in the code above causes a compile error.
Why does infix use of the comma
I hereby publish my first library in Haskell.
SVGFonts 0.1
It parses the pretty unknown SVG Font format to produce outlines of
characters. The big advantage of this format is that it is XML, which
means easy parsing and manipulating. Because I haven't found any
svg-files on the Internet the
This sounds very cool. Is is just a program, or is there a library sitting
behind it? From your .cabal file, it seems to be just a binary program.
Is this correct?
http://hackage.haskell.org/packages/archive/SVGFonts/0.1/SVGFonts.cabal
On Mon, Apr 6, 2009 at 1:22 PM, Tillmann Vogt
On Mon, Apr 6, 2009 at 10:02 AM, Sjoerd Visscher sjo...@w3future.com wrote:
Considering these naming conventions:
http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Monad.html#3
• A postfix 'M' always stands for a function in the Kleisli category: The
monad type constructor m is
Works for me. The admin address referenced there is support [AT]
community.haskell.org
On Mon, Apr 6, 2009 at 1:32 PM, Claus Reinke claus.rei...@talk21.comwrote:
I seem to be having problems reaching anything on that server.
Does anyone know what is going on, or who to contact? It would
help
On Mon, Apr 6, 2009 at 7:32 PM, Tillmann Vogt
tillmann.v...@rwth-aachen.de wrote:
It is a real library made of pure Haskell. What is wrong with my .cabal
file?
The issue is not about whether it is pure Haskell. You have simply
marked it up as an executable rather than a library.
Executable
Btw, there seem to be many Haskells on YouTube - should we have
some way of marking clips related to our Haskell? I've used haskell.org
as a tag, but noone else has, yet - also, perhaps there should be a Haskell
channel or something?
And just in case there are others on the same Windows
Hello all,
I have a haskell program that runs an order of magnitude slower
when compiled with optimisations turned on. This happens on 6.8.2
as well as 6.10.1:
p...@r4at184:/tmp[1]% ghc --make -fforce-recomp -o out buga.hs
[1 of 1] Compiling Main ( buga.hs, buga.o )
What your cabal file describes is a single executable,
Executable Fonts
main-is: tests/Fonts.hs
This just tells us to build the file tests/Fonts.hs into a single executable
named 'Fonts'. You probably want to retructure your project a bit into
something like this.
./LICENSE
./README
./Setup.hs
On Mon, Apr 6, 2009 at 11:42 AM, David Menendez d...@zednenem.com wrote:
Of course, this suggests that mfix should be fixM, so perhaps a better
distinction is that mplus and mfix need to be defined per-monad,
whereas filterM and replicateM are generic.
Don't you think that is an incidental
John Van Enk schrieb:
This sounds very cool. Is is just a program, or is there a library sitting
behind it? From your .cabal file, it seems to be just a binary program.
Is this correct?
http://hackage.haskell.org/packages/archive/SVGFonts/0.1/SVGFonts.cabal
On Mon, Apr 6, 2009 at 1:22 PM,
I seem to be having problems reaching anything on that server.
Does anyone know what is going on, or who to contact? It would
help if the haskellwiki page
http://www.haskell.org/haskellwiki/Haskell.org_domain
would mention the admin address directly, instead of referring to
Hello,
cabal generates a Paths_Xxx file for me which I import and use, but
cabal haddock doesn't seem to like it much.
If I don't specify the generated module at all in my cabal file, cabal
haddock generates visible documentation for the module, which is not
what I want: the module should
-fno-state-hack?
xofon:
Hello all,
I have a haskell program that runs an order of magnitude slower
when compiled with optimisations turned on. This happens on 6.8.2
as well as 6.10.1:
p...@r4at184:/tmp[1]% ghc --make -fforce-recomp -o out buga.hs
[1 of 1] Compiling
Works for me. The admin address referenced there is support [AT]
community.haskell.org
Thanks. Yes, it is working again for me too, now, but had been
quite persistently unreachable before, while www.haskell.org
was reachable, so I'd be surprised if the the problem was at
this end of the
Dear All,
I have an application where some simple data extracted from some
source files is inserted into a PostgreSQL database. The application
uses Takusen and is compiled with GHC 6.8.3. Some (59 in the test
data) of the selects take on average 460ms each for a total time for
this sample run of
Henning Thielemann schrieb:
On Sun, 5 Apr 2009, Kalman Noel wrote:
I'm wondering, too, if the Numeric Prelude could be organized more
cleanly if we had a fancier module system - does someone have
sufficient experience with, say, ML-style module systems to tell?
Are you complaining about
Hi Daniel,
Thanks, but apparently no go.
This isn't critical, as I already have a function that will combine two
sequences.
Michael
=
Michael
[mich...@localhost untitled folder]$ cd utility-ht-0.0.4
[mich...@localhost utility-ht-0.0.4]$ ls
LICENSE Setup.lhs src
Hi Alberto!
Thanks for your informative reply. I looked in to the versions of
liblapack on my system... it turns out there is indeed a
liblapack.dylib that (apparently) comes with Mac OS X. How to tell
ghc to link to that instead is still in question.
I can run simple matrix operations
On Mon, 6 Apr 2009, nowg...@yahoo.com wrote:
Michael
[mich...@localhost untitled folder]$ cd utility-ht-0.0.4
[mich...@localhost utility-ht-0.0.4]$ ls
LICENSE Setup.lhs src utility-ht.cabal
[mich...@localhost utility-ht-0.0.4]$ ./Setup.lhs configure --hugs
/usr/bin/env: runhaskell: No such
Hi Haskellers,
This is related to my previous message, Linking hmatrix without
LAPACK. Apparently, ghc --make is not finding the lapack.dylib
library where ghci is (dylib is Mac OS X specific) . For example, the
following test module does NOT work when compiled with ghc --make:
On Sun, 5 Apr 2009, michael rice wrote:
Thanks. It looks like mergeBy will do the job, but is it available in Hugs?
The package is Haskell98 and needs no further package, thus it should work
with almost every Haskell system.
___
Haskell-Cafe
Am Montag 06 April 2009 20:37:46 schrieb Don Stewart:
-fno-state-hack?
That, or
{-# LANGUAGE BangPatterns #-}
main = do
n - read `liftM` getLine
!pole - liftM (build n . map read . words) getLine
replicateM_ 100 $ do
getLine
print $ best pole 42 420
if the state-hack is
Hello,
is there a monad transformer to consume an input list? I've got external
events streaming into the monad that are consumed on demand and I'm
not sure if there's something better than a StateT.
//Stephan
--
Früher hieß es ja: Ich denke, also bin ich.
Heute weiß man: Es geht auch so.
-
On Mon, 6 Apr 2009, Stephan Friedrichs wrote:
Hello,
is there a monad transformer to consume an input list? I've got external
events streaming into the monad that are consumed on demand and I'm
not sure if there's something better than a StateT.
I wondered that, too. I wondered whether
To my surprise GHC seems to accept .lib files (produced by e.g. Visual
Studio on Windows) directly; I don't need to convert these to .a files using
e.g. reimp
That's really cool. Is this by design or did I miss something? The manual
does not seem to mention this.
{-# LANGUAGE TypeFamilies, TypeSynonymInstances, ScopedTypeVariables #-}
The following is a class of memo tries indexed by d:
class Fun d where
type Memo d :: * - *
abst :: (d - a) - Memo d a
appl :: Memo d a - (d - a)
-- Law: abst . appl = id
-- Law: appl . abst = id
On Mon, 6 Apr 2009, Kalman Noel wrote:
I'm not complaining, and I'm not sure what I mean :) I may like a scheme
where functions operating on a type or type class live in a module
seperate from the type (class) definition, so you could import a
specific module to get only, say, (Ring, (*), one,
Hi,
I learned that no one is doing generic unix source tarball,
right now, and thought I might help to get it start. I have
decent skills on Makefile, but knows very little about
auto-tools. I can only spent a few hours every week on it,
because I don't have too much spare time as a PhD
FYI, the following solution worked on Mac OS X (Leopard):
ghc -o SilkwormGame --make -framework Accelerate Main.hs
The key addition is -framework Accelerate. Thus, on Mac OS X, it is
only necessary to install the gls library via macports. Atlas/
LAPACK/BLAS etc. come with the operating
I've noticed this before. I in fact have really only tried FTGL with
VC compiled lib files...
On Mon, Apr 6, 2009 at 5:34 PM, Peter Verswyvelen bugf...@gmail.com wrote:
To my surprise GHC seems to accept .lib files (produced by e.g. Visual
Studio on Windows) directly; I don't need to convert
Is there a way to do something like autoconf and configure
dependencies at install time? Building buster, I keep adding
dependencies and I'd like to keep that down to a minimum without the
annoyance of littering Hackage with dozens of packages. For instance,
today I developed an HTTP behaviour
The prefix notation for
\a b c - (a,b,c)
is (,,)
Without the parentheses, it's not immediately clear whether
foo $ a,b
means
foo (a,b)
or
foo (\c - (a,b,c))
or some other, bigger tuple size.
Anyways, it's just syntax :)
-- ryan
On Mon, Apr 6, 2009 at 9:08 AM, Daniel Fischer
Dear Xiao-Yong,
thank you very much for your willingness to help.
I would suggest you look into some of the builds for various platforms
as you mentioned. One infrastructure I find particularly interesting
is pkgsrc (www.pkgsrc.org) which can be used to effortlessly build
numerous packages from
On Mon, Apr 6, 2009 at 2:36 PM, Peter Berry pwbe...@gmail.com wrote:
As I understand it, the type checker's thought process should be along
these lines:
1) the type signature dictates that x has type Memo d a.
2) appl has type Memo d1 a - d1 - a for some d1.
3) we apply appl to x, so Memo d1
Peter Berry:
{-# LANGUAGE TypeFamilies, TypeSynonymInstances,
ScopedTypeVariables #-}
The following is a class of memo tries indexed by d:
class Fun d where
type Memo d :: * - *
abst :: (d - a) - Memo d a
appl :: Memo d a - (d - a)
-- Law: abst . appl = id
-- Law: appl . abst
Is the choice of whether or not to open/close with each chunk
read something that we can reasonably hide from the I/O API's
user? There is at least one way in which is semantically
distinct -- that old trick of opening a tempfile and then
unlinking it to hide it.
It may be the sort of
I remember hearing about a Haskell mode for Vim, Emacs, Yi or
VisualHaskell that inserts type declarations automatically (it's
lazier to just check the type than to write it manually), but I can't
remember any details. What editor mode / IDE was it?
What do most people use with GHC on Linux? I'm
On Mon, Apr 6, 2009 at 8:53 AM, Paul Keir pk...@dcs.gla.ac.uk wrote:
module Main where
data (:%^) a b = a :%^ b deriving (Show)
main = do
print $ 18 :%^ (Just 99)
print $ (,) 9 10
print $ 9 , 10
The last line in the code above causes a compile error.
Why does infix
Hi,
today, I want to ask about QuickCheck.
I have known recently that arbitrary works on functions as well. I
played on this for a while, and met a strange behavior.
I tried to write property for sortBy.
import Test.QuickCheck
import Data.List
instance Show (a - b) where show _ =
Since the argument to sortBy must impose a linear ordering on its
arguments, and any linear ordering may as well be generated by
assigning an integer to each element of type 'a', and your sorting
function is polymorphic, from the free theorem for the sorting
function we may deduce that it suffices
On Mon, Apr 6, 2009 at 10:09 PM, Eugene Kirpichov ekirpic...@gmail.com wrote:
Since the argument to sortBy must impose a linear ordering on its
arguments, and any linear ordering may as well be generated by
assigning an integer to each element of type 'a', and your sorting
function is
On Mon, Apr 6, 2009 at 1:46 PM, Luke Palmer lrpal...@gmail.com wrote:
On Mon, Apr 6, 2009 at 11:42 AM, David Menendez d...@zednenem.com wrote:
Of course, this suggests that mfix should be fixM, so perhaps a better
distinction is that mplus and mfix need to be defined per-monad,
whereas
71 matches
Mail list logo