Hi all,
So my theory now is:
I do a large number of lookups.
Try using Data.Array.Base.unsafeRead (and maybe
ata.Array.Base.unsafeWrite). These avoid the bounds checking on the
index each time you lookup something in the array.
Right. Also keep an eye on the GC time (+RTS
Hi all,
I have a problem with regards to the speed of ST arrays.
In short: a Data.Map.Map outperforms Data.Array.ST in my application,
whereas as far as I understand it, the ST array should be quicker.
My application is a compiler. It compiles some source code into a (huge)
number of boolean
hardware
- is a good “team-player”
- can express himself well in English
Of course, affinity with story designing or toy designing is advantageous.
Please contact me by e-mail if you are interested!
Regards,
Robert
-
Robert van Herk
Research Scientist, IT Group, Philips
Hi all,
Is it true to say that to perform idempotent IO actions inside a STM
monad by using unsafeSTMToIO is safe? I mean something like:
do ... -- some STM actions
unsafeSTMToIO a -- Here, a is an idempotent IO action
... -- some other STM actions
What I read from the various
Hello All,
I think I've read somewhere that STM doesn't like unsafePerformIO.
However, I would like to use a global STM variable. Something like this:
*module* Main *where*
import GHC.Conc
import System.IO.Unsafe
tSid = unsafePerformIO (atomically (newTVar 0))
tickSessionID :: STM Int
Never mind, I can probably use an MVar to work around this...
Robert
Robert van Herk wrote:
Hello All,
I think I've read somewhere that STM doesn't like unsafePerformIO.
However, I would like to use a global STM variable. Something like this:
module Main where
import GHC.Conc
import
Oh I see! Your sollutions are indeed a lot better than implementating
all my code using MVars :-).
Thanks,
Robert
Remi Turk wrote:
On Wed, Aug 03, 2005 at 12:50:54PM +0200, Robert van Herk wrote:
Hello All,
I think I've read somewhere that STM doesn't like unsafePerformIO.
However, I
Hello,
I noticed that it is possible to run the garbage collector explicitely...
Currently, I am writing a stateful webserver, that once in a while (e.g.
every 30 minutes) can discard a lot of memory (because every 30 minutes
sessions time out and their state can be thrown away).
Would it
John Goerzen wrote:
On 2005-06-06, Simon Peyton-Jones [EMAIL PROTECTED] wrote:
Lots of people seem to have had problems compiling Wash with GHC 6.4.
Another person told me, perhaps in private, that it just takes GHC 15
minutes to compile the specific file in question on amd64. It
Simon Peyton-Jones wrote:
| A while ago I sent an email to the glasgow haskell users maillinglist
to
| explain how the Contexts differ in length feature (or bug :-))
| restricted me in writing a haskell application. I was hoping for a
| reply, however I didn't receive one (yet).
It's a
Hi all,
A while ago I sent an email to the glasgow haskell users maillinglist to
explain how the Contexts differ in length feature (or bug :-))
restricted me in writing a haskell application. I was hoping for a
reply, however I didn't receive one (yet).
Therefore, I will explain the problem
Hi all,
I have a question about IO in a STM transaction.
I want to make an atomic algorithm that does the following:
1. read an IORef
2. write some changes to the value you get from 1
3. save the IORef again
Currently, I did this, roughly like this:
doSomething :: IORef [s] - s - IO ()
doSomething
You probably wanna use TVars instead of IORefs.
I would suggest reading the STM paper at
research.microsoft.com/~simonpj/papers/stm/stm.ps, if you haven't
already.
ah, I read about them, and than forgot all about them again :-). Guess
will have to read about 'em again.
Thanks!
Robert
Hi all,
I am using ghc 6.4 on a Mac, with the binary distribution available from
your site.
I have a suspision that the package.conf file distributed with it, is
incorrect. I am trying to install HSQL. During installation, it issues
the command:
/usr/local/bin/ghc-pkg -u -g -i hsql.pkg
Hi Keean,
First of all, thank you for your answers. I have tried your solution
using TypeEq.
instance (Datasource l k' v', TypeEq k k' z, Datasource' z l r k v) =
Datasource (JoinedDS l r) k v where
_dsread (JoinedDS refl refr) k = do { l - readIORef refl;
Sorry, this is the compiler error I get:
No instances for (KeyHasValue MyKeyVal k' v',
Datasource.Tools.FakePrelude.TypeEq Float k' z,
Datasource' z [MyKeyVal] [MyKeyVal] Float Int)
When I am trying to do
do { createJoinedDS' x x;
Sorry, oops again:
The problem is that it complains that it cannot find an instance for
Datasource' z [MyKeyVal] [MyKeyVal] Float Int
Whilst I have an instance
Datasource [MyKeyVal] Float Int
Thus, it seems that it needs an explicit type for the z here.
Both datasources stored in the joined
See change above!
Also note type of fundep for Datasource should now be:
class Datasource s k v | s - k v where ...
I see But the cool thing was, that my datasources were generic, in
the sence that they could store multiple k's and v's. Now, they would be
unique for the actual storage
Hi all,
I need to use duplicate instances. I read in the documentation on GHC
6.4, that overlapping class instances checks are lazy instead of gready
in 6.4. However, my code still gives duplicate instance errors when
compiling in GHC 6.4.
Is the duplicate instance check still gready? Is there
Keean Schupke wrote:
Robert van Herk wrote:
Hi all,
I need to use duplicate instances. I read in the documentation on GHC
6.4, that overlapping class instances checks are lazy instead of
gready in 6.4. However, my code still gives duplicate instance errors
when compiling in GHC 6.4
key or value types, and whether the loolup is supposed
to be value or type driven. My original answer assumed a single
Datasource contains values of different types, selected by the type of
the key...
Keean.
Robert van Herk wrote:
Yes, but this is not what I want. I want to be able to give
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