Stefan O'Rear wrote:
Mr. C++ apparently isn't a very good C++ programmer, since his best
effort absolutely *pales* in comparison to Julian Seward's BWT:
[EMAIL PROTECTED]:/usr/local/src/hpaste$ head -c 135000 /usr/share/dict/words |
(time bzip2 -vvv) /dev/null
(stdin):
block 1: crc =
...OK...so how do I make Haskell go faster still?
Presumably by transforming the code into an ugly mess that nobody can
read any more...?
http://haskell.org/haskellwiki/Performance
-- Don
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Donald Bruce Stewart wrote:
Don't use -O3 , its *worse* than -O2, and somewhere between -Onot and -O iirc,
ghc -O2 -funbox-strict-fields -fvia-C -optc-O2 -optc-ffast-math
-fexcess-precision
Are usually fairly good.
Is this likely to be fixed ever?
On Sat, Jun 23, 2007 at 12:42:33AM +0100, Claus Reinke wrote:
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
I see: I guess I'm paying for laziness in the first parameter to
intersect'
On Sat, Jun 23, 2007 at 08:49:15AM +0100, Andrew Coppin wrote:
Donald Bruce Stewart wrote:
Don't use -O3 , its *worse* than -O2, and somewhere between -Onot and -O
iirc,
Is this likely to be fixed ever?
There is at least a bug report for it IIRC.
Phil
--
http://www.kantaka.co.uk/ .oOo.
On Sat, Jun 23, 2007 at 03:28:53AM +0100, Jon Harrop wrote:
What architecture, platform, compiler versions and compile lines are you
using?
32-bit x86, Debian unstable, gcc version 4.1.2, OCaml version
3.09.2-9, GHC version 6.6.1, compile line in the Makfile at
On Saturday 23 June 2007 08:18, Chad Scherrer wrote:
Now, the UNIX command doesn't really cut it, because it complains there are
too many files,
Sounds like a case for xargs(1)?
Alexis.
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Greg Meredith wrote:
First, has anyone worked out a monadic
approach to copy-on-write? (And, Is there any analysis of perf
characteristics of said monadic schemes?)
If you use Zippers (Huet's or generic ones) with functional updates,
copy-on-write comes out automatically and by default. This
There is a number of problems, I'm not sure which one you are encountering.
Here are some that I remember:
The sample C code doesn't shut down the ghc runtime properly when the DLL
is unloaded. This causes a timer interrupt to jump into the void. This is
easily fixed with a couple of more
apfelmus wrote:
Note that the one usually adds an end of string character $ in the
Burrows-Wheeler transform for compression such that sorting rotated
strings becomes sorting suffices.
Yeah, I noticed that the output from by program can never actually be
reverted to its original form. ;-)
2007/6/22, Andrew Coppin [EMAIL PROTECTED]:
Chaddaï Fouché wrote:
You should be using BS.null f rather than BS.length f 0.
While we're on the subject... anybody know a neat way to check, say,
whether a list contains exactly 1 element? (Obviously pattern matching
can do it, but that requires
On Saturday 23 June 2007 08:58:10 Philip Armstrong wrote:
On Sat, Jun 23, 2007 at 03:28:53AM +0100, Jon Harrop wrote:
What architecture, platform, compiler versions and compile lines are you
using?
32-bit x86...
Intel or AMD?
On Saturday 23 June 2007 08:54:11 Philip Armstrong wrote:
On Sat, Jun 23, 2007 at 12:42:33AM +0100, Claus Reinke wrote:
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
I see: I guess
Andrew Coppin wrote:
apfelmus wrote:
Note that the one usually adds an end of string character $ in the
Burrows-Wheeler transform for compression such that sorting rotated
strings becomes sorting suffices.
Yeah, I noticed that the output from by program can never actually be
reverted to
Bulat Ziganshin wrote:
Hello Andrew,
bwt transformation is very good researched area, so probably you will
not get decent performance (megabytes per second) without lot of work.
Hey, I'm just glad I managed to get within striking distance of Mr C++.
So much for Haskell being inherently
On 6/23/07, Chaddaï Fouché [EMAIL PROTECTED] wrote:
isLength1 [x] = Ok
isLength _ = Nok
excellent.
How is [x] big in any way ? If you need to test for more than one
element you can just put put a guard with length
Invoking length is more strict than is necessary, though this may not
be a
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
also try replacing that (foldl' intersect') with (foldr (flip intersect'))!
using a recent ghc head instead of ghc-6.6.1 also seems to
make
Hi,
I am writing a Web application using HAppS.
As all HAppS apps, it represents its internal state as a Haskell term (HAppS
automagically provides persistence and transactions).
It is a neat and efficient solution, you can write your data model entirely in
Haskell and, at least for read-only
Hello Andrew,
Saturday, June 23, 2007, 2:45:01 PM, you wrote:
Hey, I'm just glad I managed to get within striking distance of Mr C++.
So much for Haskell being inherently less performant. :-P
my little analysis says that it's probably due to different sort()
implementations, so this says
Am Freitag, 22. Juni 2007 22:43 schrieb Stefan O'Rear:
On Fri, Jun 22, 2007 at 10:37:55PM +0200, Daniel Fischer wrote:
I can partially answer my questions.
Removing also Seen does away with the ByteString.index error.
Must check the code to see why.
Two more concrete questions
a) how
On Saturday 23 June 2007 12:05:01 Claus Reinke wrote:
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
also try replacing that (foldl' intersect') with (foldr (flip intersect'))!
using
Bulat Ziganshin wrote:
Hello Andrew,
Saturday, June 23, 2007, 2:45:01 PM, you wrote:
Hey, I'm just glad I managed to get within striking distance of Mr C++.
So much for Haskell being inherently less performant. :-P
my little analysis says that it's probably due to different sort()
On Saturday 23 June 2007 13:02:54 Andrew Coppin wrote:
Well, I altered the code, and it's *still* very short and very readable,
and it's just as fast as the (3 pages long) C++ version. :-D
Indeed. The performance of modern functional programming languages never
ceases to amaze me. INRIA
Hi
I have most of a Data.Nat library done, I should finish it off and release it...
Thanks
Neil
On 6/22/07, Stefan O'Rear [EMAIL PROTECTED] wrote:
On Fri, Jun 22, 2007 at 07:14:39PM +0100, Andrew Coppin wrote:
Chaddaï Fouché wrote:
You should be using BS.null f rather than BS.length f 0.
Hi
Parallel: I think this is pretty well solved with STM. I think STM is
production ready in GHC.
Exceptions: These are less well solved, people are still thinking
about some of the issues. In general, you probably don't want to use
exceptions too much - the Maybe Monad is often a better
Bulat Ziganshin wrote:
Hello Andrew,
definitive reading: Tackling the awkward squad: monadic input/output,
concurrency, exceptions, and foreign-language calls in Haskell
http://research.microsoft.com/Users/simonpj/papers/marktoberdorf/marktoberdorf.ps.gz
I've read it.
Is everything
Hello Andrew,
Saturday, June 23, 2007, 7:12:52 PM, you wrote:
Is everything described in that paper actually implemented now? (And
implemented in exactly the same way as the paper says?)
difference may be in subtle details. it just works for me :)
in my experience, exceptions are rarely
On Saturday 23 June 2007 13:52:27 Neil Mitchell wrote:
Hi
Regarding the first point, I am aware of with the following options:
- SYB (Data.Generics..)
You may also want to take a look at Uniplate:
http://www-users.cs.york.ac.uk/~ndm/uniplate/
Many thanks Neil.
That (or SYB) should take
On 22 jun 2007, at 22.17, Derek Elkins wrote:
[blah blah blah]
A less (potentially) offensive way of formulating this is:
[...]
or
-snip-
(You know, we don't want to accidentally piss of any newcomers. So
just saying .. :)
___
Hello Andrew,
Saturday, June 23, 2007, 5:59:45 PM, you wrote:
The two things mentioned in the subject line are both things I've never
tried with Haskell. I've seen a lot of papers about these things, but I
don't really understand what the current state of play with this is. Are
any of these
Hello Andrew,
Saturday, June 23, 2007, 4:02:54 PM, you wrote:
The point being that lots of people look at Haskell and go oh, that's
very cute for writing trivial example code, but it can never be fast;
for that you must use C or C++.
and that's true :) as i said, your C++ code is very far
Hi
Regarding the first point, I am aware of with the following options:
- SYB (Data.Generics..)
You may also want to take a look at Uniplate:
http://www-users.cs.york.ac.uk/~ndm/uniplate/
That (or SYB) should take care of your query/transform issues, and the
ACL stuff can be layered on top
The two things mentioned in the subject line are both things I've never
tried with Haskell. I've seen a lot of papers about these things, but I
don't really understand what the current state of play with this is. Are
any of these things production-ready yet? And how do you use them in
the real
On Sat, Jun 23, 2007 at 01:48:37PM +0200, Daniel Fischer wrote:
Am Freitag, 22. Juni 2007 22:43 schrieb Stefan O'Rear:
On Fri, Jun 22, 2007 at 10:37:55PM +0200, Daniel Fischer wrote:
I can partially answer my questions.
Removing also Seen does away with the ByteString.index error.
Must
Perhaps in here we should start using
\x - (unlines . (dropWhile (/= x)) . lines)
Instead :)
Dave,
On 23/06/07, Thomas Schilling [EMAIL PROTECTED] wrote:
On 22 jun 2007, at 22.17, Derek Elkins wrote:
[blah blah blah]
A less (potentially) offensive way of formulating this is:
[...]
Ben Rudiak-Gould wrote:
It's not definable, and there is a good reason. Existential boxes in
principle contain an extra field storing their hidden type, and the type
language is strongly normalizing.
Thank you very much for the answer: indeed, I suspected strong
normalization for types had
On Sat, Jun 23, 2007 at 12:05:01PM +0100, Claus Reinke wrote:
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
also try replacing that (foldl' intersect') with (foldr (flip intersect'))!
I'm experimenting with wxHaskell. I created a small program with it
on Windows. (Well, small in source form, not so small in binary form
:-) The program runs fine when invoked at a Windows command line.
But if I double-click the .exe file, I get a command window that
hangs around (but
On Sat, Jun 23, 2007 at 07:07:49PM +0100, Philip Armstrong wrote:
On Sat, Jun 23, 2007 at 12:05:01PM +0100, Claus Reinke wrote:
http://www.kantaka.co.uk/darcs/ray
try making ray_sphere and intersect' local to intersect,
then drop their constant ray parameter. saves me 25%.
claus
also try
On Sat, Jun 23, 2007 at 10:32:31AM +0100, Jon Harrop wrote:
On Saturday 23 June 2007 08:58:10 Philip Armstrong wrote:
On Sat, Jun 23, 2007 at 03:28:53AM +0100, Jon Harrop wrote:
What architecture, platform, compiler versions and compile lines are you
using?
32-bit x86...
Intel or AMD?
AMD.
On Sat, 23 Jun 2007, Dean Herington wrote:
But if I double-click the .exe file, I get a command window that hangs around
(but doesn't appear to do anything, fortunately) until the program terminates.
How can I avoid this command window?
With gtk2hs, using -optl-mwindows as a command line
On Sat, 23 Jun 2007, Dean Herington wrote:
But if I double-click the .exe file, I get a command window that hangs around
(but doesn't appear to do anything, fortunately) until the program terminates.
How can I avoid this command window?
With gtk2hs, using -optl-mwindows as a command line
Hi
All the puffing about the advantages of
strong typing look pretty silly if code hangs up on an incomplete
pattern.
Okay... people who don't worry so much about incomplete patterns believe
that they get things done.
There are trade offs in type systems about how much effort you want to
Andrew Coppin wrote:
apfelmus wrote:
Note that the one usually adds an end of string character $ in the
Burrows-Wheeler transform for compression such that sorting rotated
strings becomes sorting suffices.
Yeah, I noticed that the output from by program can never actually be
reverted
On Fri, Jun 22, 2007 at 03:14:06PM -0700, Stefan O'Rear wrote:
On Fri, Jun 22, 2007 at 06:11:24PM -0400, Brandon S. Allbery KF8NH wrote:
(1) any way to flag a pattern match as I know this is okay, don't
warn about it without shutting off pattern match warnings completely?
case
On Fri, Jun 22, 2007 at 05:39:10PM -0700, Dave Bayer wrote:
On Jun 22, 2007, at 4:37 PM, David Roundy wrote:
You get strongly-typed code whether or not you enable warnings.
In my opinion it's delusional to think one is using strong typing if
one doesn't enable warnings. All the puffing
On 6/23/07, Andrew Coppin [EMAIL PROTECTED] wrote:
It's nice that you can have millions of threads if you want to do
something very concurrent. What I tend to want is parallel - doing
stuff that *could* be done in a single thread, but I want it to go
faster using my big mighty multicore box. As
If you don't run into graphs you are either solving very peculiar problems,
or you don't recognize them when you see them. They are everywhere.
On 6/22/07, Andrew Coppin [EMAIL PROTECTED] wrote:
Dan Piponi wrote:
Andrew said:
True enough - but that's a rather specific task. I'm still not
I noticed that both the Data.Array library and the Data.Map library use the (!) operator for
different purposes. How would it be possible to import both libraries usefully in a single module?
I guess what I'm really asking is: how do I qualify operator names?
Mike
On Sat, Jun 23, 2007 at 04:53:51PM -0700, Michael Vanier wrote:
I noticed that both the Data.Array library and the Data.Map library use the
(!) operator for different purposes. How would it be possible to import
both libraries usefully in a single module? I guess what I'm really asking
I enjoy code like this that requires laziness. My modified version of your code
is below...
Bertram Felgenhauer wrote:
Code:
bwt implements a variation of the Burrows-Wheeler transform, using
\0 as a sentinel character for simplicity. The sentinel has to be smaller
than all other
On 6/23/07, Bertram Felgenhauer [EMAIL PROTECTED] wrote:
rbwt implements the corresponding inverse BWT. It's a fun knot tying
exercise.
rbwt xs = let
res = sortBy (\(a:as) (b:bs) - a `compare` b) (zipWith' (:) xs res)
in
tail . map snd . zip xs $ head res
Indeed it's very fun
Felipe Almeida Lessa wrote:
On 6/23/07, Bertram Felgenhauer [EMAIL PROTECTED] wrote:
rbwt implements the corresponding inverse BWT. It's a fun knot tying
exercise.
rbwt xs = let
res = sortBy (\(a:as) (b:bs) - a `compare` b) (zipWith' (:) xs
res)
in
tail . map snd . zip xs $
Felipe Almeida Lessa wrote:
On 6/23/07, Bertram Felgenhauer [EMAIL PROTECTED] wrote:
rbwt implements the corresponding inverse BWT. It's a fun knot tying
exercise.
rbwt xs = let
res = sortBy (\(a:as) (b:bs) - a `compare` b) (zipWith' (:) xs res)
in
tail . map snd . zip xs $
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