On Sun, Jul 26, 2009 at 10:27:41PM +0200, Grzegorz ChrupaĆa wrote:
Hi all,
I have a piece of code where I'm serializing a datastructure with the
following type [(Int, (Map DType (IntMap Int)))], using Binary.encode
The thing is it is very slow: actually quite a bit slower than just using
show.
Th
On Tue, Feb 24, 2009 at 10:25:56AM -0500, Peter Hilal wrote:
Where do I go from here? Thank you so much.
A hint: I don't think you can do it by recursion on (/). You'll need
an auxiliary function. Then prove that your function satisfies the
constraint.
Phil (Unless there's some clever way to
On Tue, Mar 18, 2008 at 09:41:15AM -0700, Justin Bailey wrote:
Two years ago I would have agreed with that statement. Now - no way.
Make the compiler work for you. I've done a lot of Ruby development
and I would never use it for a project of more than 3 or 4 people.
It's an awesome language but I
On Mon, Mar 10, 2008 at 11:33:58PM +, Dave Tapley wrote:
I've been plugging away at this all day and some discussion in
#haskell has been fruitless. Perhaps you have the inspiration to see
what's happening!
Concerning this minimal example:
http://hpaste.org/6268
It works as required, loadin
On Mon, Feb 18, 2008 at 05:56:41PM +, Adrian Hey wrote:
Philip Armstrong wrote:
On Sun, Feb 17, 2008 at 10:01:14PM +, Adrian Hey wrote:
BTW, I find this especially ironic as fromDistinctAscList is the perfect
example what I was talking about in another thread (continuation passing
On Sun, Feb 17, 2008 at 11:45:26PM +, Adrian Hey wrote:
But I guess this rant is not much help to the OP :-)
Can the Get Monad from Data.Binary be replaced by the one in
Data.Binary.Strict.Get?
Would probably require some hacking on the library I guess.
Phil
--
http://www.kantaka.co.uk/
On Sun, Feb 17, 2008 at 10:01:14PM +, Adrian Hey wrote:
Philip Armstrong wrote:
Since no-one else has answered, I'll take a stab.
Obiously, you have a stack leak due to laziness somewhere
I wouldn't say that was obvious, though it is certainly a
possibility.
I'm never exa
On Thu, Feb 14, 2008 at 04:56:39AM -0800, Grzegorz Chrupala wrote:
I have a very simple program which reads a Data.Map from a file using
Data.Binary and Data.ByteString.Lazy, which gives stack overflow with files
over a certain size. Any ideas of what might be causing it?
You can try it with the
On Fri, Feb 01, 2008 at 10:19:17PM +, Lennart Augustsson wrote:
It's a matter of taste. I prefer the function composition in this case.
It reads nicely as a pipeline.
(Hoping not to contribute to any flamage...)
I've always liked $ for this kind of code, if you want to keep the
argume
On Thu, Nov 15, 2007 at 02:56:32PM +0900, Daisuke IKEGAMI wrote:
Dear Stefan and Haskell-Cafe,
Thanks to keeping your interest to the flymake-mode for Haskell.
Stefan wrote:
Could you explain to me what flycheck_haskell.pl does, and give an
example of a problematic situation solved by the use
On Fri, Nov 16, 2007 at 02:44:33PM +, PR Stanley wrote:
I understand 2%4 will construct a fraction in Haskell. I've tried this in
GHCI but got an error message. Is there such an operator in Prelude and if
so how is it applied?
It's not in the Prelude, it's in the Ratio module IIRC.
Phil
On Thu, Nov 15, 2007 at 09:19:10AM -0500, Denis Bueno wrote:
On Nov 15, 2007 7:25 AM, Philip Armstrong <[EMAIL PROTECTED]> wrote:
I can pass on patches if anyone cares.
I care!
Will dig them out asap then!
Phil
--
http://www.kantaka.co.uk/ .oOo. public key: http://www.kantaka
On Wed, Nov 07, 2007 at 10:41:53AM +0100, Dusan Kolar wrote:
I use tar.bz2 binary distribution of GHC compiler as my distro does not
use any supported packaging system. Everything is fine, but... I want to
install the new version of the GHC compiler. Is there any (easy) way, how
to get informa
Don's reply didn't reach me for some reason, but pulling it out of the
previous response:
On 21/08/07, Donald Bruce Stewart <[EMAIL PROTECTED]> wrote:
phil:
> The generated assembler suggests (if I've read it correctly) that gcc
> is spotting that it can replace the tail call with a jump in the
On Tue, Aug 21, 2007 at 05:25:49AM -0700, Stefan O'Rear wrote:
On Tue, Aug 21, 2007 at 01:14:20PM +0100, Rodrigo Queiro wrote:
On my system, the C version runs about 9x faster than the haskell
version (with -O3 and -O2 -fvia-c -optc-O3 respectively). However, GCC
seems to produce about 70 lines
On Mon, Aug 20, 2007 at 09:57:38PM +0100, Simon Peyton-Jones wrote:
GHC does some constant folding, but little by way of strength
reduction, or using shifts instead of multiplication. It's pretty
easy to add more: it's all done in a single module. Look at
primOpRules in the module PrelRules.
P
On Mon, Jul 23, 2007 at 11:46:41AM -0700, Dan Piponi wrote:
Ian said:
Can you please give a complete testcase for the problem you're seeing?
I took my test case and started deleting lines from it to simplify it.
And now I'm not seeing the problem at all and I can't reproduce it,
even though w
On Thu, Jul 12, 2007 at 10:11:07PM +0100, Andrew Coppin wrote:
Felipe Almeida Lessa wrote:
On 7/12/07, Andrew Coppin <[EMAIL PROTECTED]> wrote:
How come the set of all sets doesn't exist?
http://www.google.com/search?q=set+of+all+sets
leads to http://en.wikipedia.org/wiki/Set_of_all_sets whic
On Thu, Jul 12, 2007 at 04:58:43PM -0400, Steve Schafer wrote:
On Thu, 12 Jul 2007 21:24:24 +0100, you wrote:
Given that (IIRC) the BOM is just a valid unicode non-breaking space,
your scripts really ought to cope...
Choking on the BOM is probably just a symptom of a deeper problem. My
bet is
On Wed, Jul 11, 2007 at 10:31:36PM +0200, Hugh Perkins wrote:
Ok so I played with the tweaked problem (Unix 'uniq'), and getting it to
be lazy. This seems to work:
It's slightly worse than that: unix uniq only eliminates *consecutive*
identical lines from its input. If you want to eliminat
On Thu, Jul 12, 2007 at 09:24:24PM +0100, Philip Armstrong wrote:
On Thu, Jul 12, 2007 at 07:01:31PM +0100, Andrew Coppin wrote:
Let me put it this way: It makes all my Tcl scripts stop working, and it
makes my Haskell-based processor go nuts too...
Given that (IIRC) the BOM is just a valid
On Thu, Jul 12, 2007 at 07:01:31PM +0100, Andrew Coppin wrote:
Let me put it this way: It makes all my Tcl scripts stop working, and it
makes my Haskell-based processor go nuts too...
Given that (IIRC) the BOM is just a valid unicode non-breaking space,
your scripts really ought to cope...
Phi
On Mon, Jul 09, 2007 at 06:53:15PM +1000, Donald Bruce Stewart wrote:
phil:
On Mon, Jul 09, 2007 at 02:42:49PM +1000, Donald Bruce Stewart wrote:
>Processing larger amounts of data, compression, serialisation and calling
>C.
Just a thought: is it worth sticking this up on the wiki?
http:
On Mon, Jul 09, 2007 at 06:05:44PM +0200, Marc Weber wrote:
Another idea I've been pondering is allowing people to add links to
documentation for libraries, from their hackage page. We have a fair
few libs documented in blog form, here,
Beeing able adding some comments (wiki style) would be c
On Mon, Jul 09, 2007 at 02:42:49PM +1000, Donald Bruce Stewart wrote:
Processing larger amounts of data, compression, serialisation and calling C.
Just a thought: is it worth sticking this up on the wiki?
Phil
--
http://www.kantaka.co.uk/ .oOo. public key: http://www.kantaka.co.uk/gpg.txt
___
On Thu, Jul 05, 2007 at 09:41:23AM -0700, Dave Bayer wrote:
There are people who claim with a straight face that they migrated to OS X
primarily to use TextMate
http://www.textmate.com
Presumably you mean http://macromates.com/ ?
Phil
--
http://www.kantaka.co.uk/ .oOo. public key: h
On Thu, Jul 05, 2007 at 10:49:17AM +0400, Miguel wrote:
R> Another interesting thing I've discovered is:
Prelude>> length [1..100]
R> 100
Prelude>> Data.List.genericLength [1..100]
R> *** Exception: stack overflow
R> Maybe there is something wrong with Integer ?
No, there is some
On Thu, Jul 05, 2007 at 08:50:42AM +1000, Donald Bruce Stewart wrote:
[useful stuff]
So, in fact pretty much everything I was looking for exists, in some
form or other!
It's just a bit hard to find at the moment, perhaps because none of
this stuff is regarded as 'core Haskell' by any of the tuto
On Wed, Jul 04, 2007 at 07:36:11PM +0100, Andrew Coppin wrote:
Philip Armstrong wrote:
[1] Which sick application *needs* intermixed endianness?
*Clearly* you've never been to Singapore...
...er, I mean, "Ever tried playing with networking protocol stacks?"
No (thankfully?).
On Wed, Jul 04, 2007 at 09:15:59PM +0400, Bulat Ziganshin wrote:
Does that mean that the code is unwritten or that the documentation is
unwritten. IAMFI :)
of course all "unwritten" notes means unfinished docs. library
contains more than 100 functions so it was not easy to document them
all. yo
On Wed, Jul 04, 2007 at 06:52:08PM +0400, Bulat Ziganshin wrote:
Hello Philip,
Wednesday, July 4, 2007, 5:50:42 PM, you wrote:
This doesn't seem to deal with endianness. Am I missing something?
alternative:
http://haskell.org/haskellwiki/Library/AltBinary
http://haskell.org/haskellwiki/Librar
On Wed, Jul 04, 2007 at 09:44:13PM +1000, Donald Bruce Stewart wrote:
Binary instances are pretty easy to write. For a simple data type:
> instance Binary Exp where
> put (IntE i) = do put (0 :: Word8)
> put i
> put (O
On Wed, Jul 04, 2007 at 09:02:15PM +1000, Donald Bruce Stewart wrote:
phil:
On Sun, Jul 01, 2007 at 06:07:13PM +0100, Andrew Coppin wrote:
>I haven't actually tried, but presumably a TCP connection is represented
>in the same way as a file, and so has the same problems.
>
>Basically doing bina
On Sun, Jul 01, 2007 at 06:07:13PM +0100, Andrew Coppin wrote:
I haven't actually tried, but presumably a TCP connection is represented in
the same way as a file, and so has the same problems.
Basically doing binary I/O seems to be one of those things that in Haskell
falls into the class of "i
On Mon, Jul 02, 2007 at 12:23:36AM +0200, Hugh Perkins wrote:
Clll :-) Thanks for the link.
Er are you the Philip Armstrong I was at college with
Shhh. Don't tell everyone or they'll all want one. (iow, yes: Probably.)
Phil
--
http://www.kantaka.co.uk/ .oOo.
On Sun, Jul 01, 2007 at 10:48:11PM +0200, Hugh Perkins wrote:
On 7/1/07, Bulat Ziganshin <[EMAIL PROTECTED]> wrote:
> btw, are you read Hoar's book "Communicating Sequential Processes"? i
> think that his model is very FPish and reading his book should allow
> to switch your look at conc
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
als
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
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'))!
T
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
http://www.kantaka.co.uk/darcs/
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. pub
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' whi
On Fri, Jun 22, 2007 at 10:11:27PM +0400, Bulat Ziganshin wrote:
Friday, June 22, 2007, 7:36:51 PM, you wrote:
Langauge File Time in seconds
Haskell ray.hs 38.2
OCamlray.ml 23.8
g++-4.1 ray.cpp 12.6
can you share sourcecode of this variant? i'm interested to see how
much it is
On Fri, Jun 22, 2007 at 11:31:17PM +0800, Michael T. Richter wrote:
1. Using foldr means I'll be traversing the whole list no matter what.
This implies (perhaps for a good reason) that it can only work on a
finite list.
foldr is lazy.
Please tell me I'm wrong and that I'm mis
On Thu, Jun 21, 2007 at 01:45:04PM +0100, Philip Armstrong wrote:
As I said, I've tried the obvious things & they didn't make any
difference. Now I could go sprinkling $!, ! and seq around like
confetti but that seems like giving up really.
OK. Looks like I was mistaken. Strictne
On Fri, Jun 22, 2007 at 01:16:54PM +0100, Simon Marlow wrote:
Philip Armstrong wrote:
IIRC, it is possible to issue an instruction to the x86 FP unit which
makes all operations work on 64-bit Doubles, even though there are
80-bits available internally. Which then means there's no requireme
On Thu, Jun 21, 2007 at 08:42:57PM +0100, Philip Armstrong wrote:
On Thu, Jun 21, 2007 at 03:29:17PM -0400, Mark T.B. Carroll wrote:
Philip Armstrong <[EMAIL PROTECTED]> writes:
(snip)
Why on earth would you use -fexcess-precision if you're using Floats?
The excess precision onl
On Thu, Jun 21, 2007 at 03:29:17PM -0400, Mark T.B. Carroll wrote:
Philip Armstrong <[EMAIL PROTECTED]> writes:
(snip)
Why on earth would you use -fexcess-precision if you're using Floats?
The excess precision only apples to Doubles held in registers on x86
IIRC. (If you spill a Do
On Thu, Jun 21, 2007 at 08:15:36PM +0200, peterv wrote:
So float math in *slower* than double math in Haskell? That is interesting.
Why is that?
BTW, does Haskell support 80-bit "long double"s? The Intel CPU seems to use
that format internally.
As I understand things, that is the effect of
On Thu, Jun 21, 2007 at 01:29:56PM -0400, Mark T.B. Carroll wrote:
Philip Armstrong <[EMAIL PROTECTED]> writes:
(snip)
Because the optimisation page on the haskell wiki is very explicit
about never using Float when you can use Double, that's why.
(snip)
Is that still true if you u
On Thu, Jun 21, 2007 at 01:39:24PM +0100, Jon Harrop wrote:
Awesome stuff!
On Thursday 21 June 2007 12:36:27 Philip Armstrong wrote:
On Thu, Jun 21, 2007 at 12:25:44PM +0100, Sebastian Sylvan wrote:
>Try using floats for the vector, and strict fields (add a ! to the
>fields in th
On Thu, Jun 21, 2007 at 04:23:37PM +0400, Bulat Ziganshin wrote:
Thursday, June 21, 2007, 3:36:27 PM, you wrote:
revision used Float and it was slower than the current one. Making the
datatypes strict also makes no difference.
don't forget to use either -funpack-strict-fields or {#- UNPACK -#}
On Thu, Jun 21, 2007 at 12:25:44PM +0100, Sebastian Sylvan wrote:
Try using floats for the vector, and strict fields (add a ! to the
fields in the data declaration).
Because the optimisation page on the haskell wiki is very explicit
about never using Float when you can use Double, that's why. A
In odd spare moments, I took John Harrops simple ray tracer[1] & made a
Haskell version:
http://www.kantaka.co.uk/cgi-bin/darcsweb.cgi?r=ray
darcs get http://www.kantaka.co.uk/darcs/ray
It's pretty much a straight translation into idiomatic Haskell (as far
as my Haskell is idiomatic anyway).
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