[Haskell-cafe] trick to easily generate Eq/Ord instances
Hello
sometimes, Eq/Ord classes can't be derived automatically because we
need to comare only part of fields. in such situations i use the
following trick to easify generation of class instances:
data ArchiveBlock = ArchiveBlock {
blArchive :: Archive
, blType:: BlockType
, blCompressor :: Compressor
, blPos :: Integer
, blOrigSize:: Integer
, blCompSize:: Integer
, blCRC :: CRC
, blFiles :: Int
}
instance Eq ArchiveBlock where
(==)= map2eq $ map3 (blArchive,blPos,blCRC)
instance Ord ArchiveBlock where
compare = map2cmp $ map2 (blArchive,blPos)
{-
instance Ord ArchiveBlock where
compare = map2cmp blPos -- for comparision on just one field
-}
-- Utility functions
map2 (f,g) a = (f a, g a)
map3 (f,g,h) a = (f a, g a, h a)
keyval f x= (f x, x)-- |Return pair containing computed
key and original value
map2cmp f x y = (f x) `compare` (f y) -- |Converts key_func to
compare_func
map2eq f x y = (f x) == (f y) -- |Converts key_func to eq_func
--
Best regards,
Bulat mailto:[EMAIL PROTECTED]
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Re: [Haskell-cafe] Bringing Erlang to Haskell
Hello Joel, Monday, December 12, 2005, 7:00:46 PM, you wrote: JR 1) Processes, aka threads with single-slot in/out mailboxes are you read dewscription of my own Process library in haskell maillist? JR One particular thing that bugs me is that I cannot really use TChan JR for thread mailboxes. i use. but i limit number of messages in this channel by additional tools. you can easily do the same. but first ask yourself - what you will gain by this? imho, it will only help to smooth temporary speed changes. if you just want to test whether this can speed up your program - implement such limited Channel and test whether it works btw, i suggested you to try not using logging thread entirely, making all logging actions synchronously JR I found single-slot mailboxes (TMVar) to work much better as they JR pace the overall message flow. Using them means that asynchronous JR messages cannot be implemented, though. not exactly. they can hold at most one message i think that your aspiration to make things asynchronous is just sort of fashion. what you really want to get? -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re[2]: [Haskell-cafe] Tricky exception handling
Hello Joel, Monday, December 12, 2005, 7:26:23 PM, you wrote: JR Unless I'm mistaken, the code above will run forever and will not JR exit on exception. yes, you are muistaken! :) this code will repeat permanently until exception arrived. at this time it will process exception handler and then exit the whole function. you musr reread docs. hmm, actually this is the way exception handling works in ANY language handle (...) repeat_forever do cmd - read h ssl post $! Cmd $! cmd JR -- JR http://wagerlabs.com/ -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re[2]: [Haskell-cafe] Opening the same file multiple times
Hello Einar,
Monday, December 12, 2005, 5:01:20 PM, you wrote:
EK 3) Using System.Posix.IO
EK Using the fd{Read,Close,Write} functions from System.Posix.IO
EK could solve the problem - except that there is no way to
EK write binary buffers (Ptr Word8) with the API. Thus no
EK solution.
you can easily import these functions via FFI:
foreign import ccall unsafe HsBase.h read
c_read :: CInt - Ptr CChar - CSize - IO CSsize
moreover, they are already imported by System.Posix.Internals. and
even more - it works both under Windows and Unix
below is a part of file api i proposed for inclusion in ghc. i think
it is exactly what you need:
{-# OPTIONS_GHC -fvia-C -fglasgow-exts -fno-monomorphism-restriction#-}
module FD where
import Control.Monad
import Data.Bits
import Data.Int
import Data.Word
import Foreign.C.Types
import Foreign.C.Error
import Foreign.C.String
import Foreign.Marshal.Alloc
import Foreign.Ptr
import System.IO
import System.IO.Error
import System.Posix.Internals
import System.Posix.Types
import System.Win32
type FD = CInt-- handle of open file
type CWFilePath = CString -- filename in C land
type CWFileOffset = COff -- filesize or filepos in C land
type FileSize = Integer -- filesize or filepos in Haskell land
withCWFilePath = withCString -- FilePath-CWFilePath conversion
peekCWFilePath = peekCString -- CWFilePath-FilePath conversion
fdOpen :: String - CInt - CMode - IO FD
fdOpen name access mode =
modifyIOError (`ioeSetFileName` name) $
withCWFilePath name $ \ p_name -
throwErrnoIfMinus1Retry fdOpen $
c_open p_name access mode
fdClose :: FD - IO ()
fdClose fd =
throwErrnoIfMinus1Retry_ fdClose $
c_close fd
fdGetBuf :: FD - Ptr a - Int - IO Int
fdGetBuf fd buf size =
fromIntegral `liftM`
(throwErrnoIfMinus1Retry fdGetBuf $
c_read fd (castPtr buf) (fromIntegral size))
fdPutBuf :: FD - Ptr a - Int - IO ()
fdPutBuf fd buf size =
throwErrnoIfMinus1Retry_ fdPutBuf $
c_write fd (castPtr buf) (fromIntegral size) -- to do: check that
result==size?
fdTell :: FD - IO FileSize
fdTell fd =
fromIntegral `liftM`
throwErrnoIfMinus1Retry fdTell
(c_tell fd)
fdSeek :: FD - SeekMode - FileSize - IO ()
fdSeek fd mode offset =
throwErrnoIfMinus1Retry_ fdSeek $
c_lseek fd (fromIntegral offset) whence
where whence = case mode of
AbsoluteSeek - sEEK_SET
RelativeSeek - sEEK_CUR
SeekFromEnd - sEEK_END
fdFileSize :: FD - IO FileSize
fdFileSize fd =
fromIntegral `liftM`
throwErrnoIfMinus1Retry fdFileSize
(c_filelength fd)
{-open/close/truncate/dup
new_fd - throwErrnoIfMinus1 dupHandle $
c_dup (fromIntegral (haFD h_))
new_fd - throwErrnoIfMinus1 dupHandleTo $
c_dup2 (fromIntegral (haFD h_)) (fromIntegral (haFD hto_))
-}
foreign import ccall unsafe HsBase.h tell
c_tell :: CInt - IO COff
foreign import ccall unsafe HsBase.h filelength
c_filelength :: CInt - IO COff
foreign import ccall unsafe __hscore_bufsiz dEFAULT_BUFFER_SIZE :: Int
foreign import ccall unsafe __hscore_seek_cur sEEK_CUR :: CInt
foreign import ccall unsafe __hscore_seek_set sEEK_SET :: CInt
foreign import ccall unsafe __hscore_seek_end sEEK_END :: CInt
i=fromIntegral
--
Best regards,
Bulatmailto:[EMAIL PROTECTED]
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Re: [Haskell-cafe] Bringing Erlang to Haskell
On Dec 13, 2005, at 1:13 AM, Bulat Ziganshin wrote: are you read dewscription of my own Process library in haskell maillist? No. Can you give me a pointer? btw, i suggested you to try not using logging thread entirely, making all logging actions synchronously I cannot. Only one thread can use stdout, otherwise the output is garbled. Plus, combing through a few thousand individual files produced by the threads would be a pain. i think that your aspiration to make things asynchronous is just sort of fashion. what you really want to get? I have no such aspirations. I was just making a point. Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Re[2]: [Haskell-cafe] Tricky exception handling
Yes, you are right. I will make the change. On Dec 13, 2005, at 9:28 AM, Bulat Ziganshin wrote: yes, you are muistaken! :) this code will repeat permanently until exception arrived. at this time it will process exception handler and then exit the whole function. you musr reread docs. hmm, actually this is the way exception handling works in ANY language handle (...) repeat_forever do cmd - read h ssl post $! Cmd $! cmd -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Bringing Erlang to Haskell
On Dec 13, 2005, at 9:49 AM, Tomasz Zielonka wrote: On Mon, Dec 12, 2005 at 04:00:46PM +, Joel Reymont wrote: One particular thing that bugs me is that I cannot really use TChan for thread mailboxes. I don't think I experienced this problem with Erlang but using a TChan with a logger thread quickly overwhelms the logger and fills the TChan and a lot (hundreds? thousands) of other threads are logging to it. I wonder what Erlang does to solve this problem? Perhaps we should track the number of unprocessed messages in TChans and the bigger it is the more favor consumers over producers. It sounds to me that introducing thread priorities would be key. Here's a reply from Ulf Wiger (and Erlang expert): Erlang has four process priorities: - 'max' and 'high' are strict priorities (you stay at that level while there are processes ready to run) - normal and low are scheduled fairly, I believe with 8000 reductions (roughly function calls) at normal priority and one low-priority job (if such a job exists) The scheduler works on reduction count. A context switch happens if the current process would block (e.g. if it's in a receive statement and there is no matching message in the queue), or when it's executed 1000 reductions. Since not all operations are equal in cost, there is an internal function called erlang:bump_reductions(N). File operations are usually followed by a call to erlang:bump_reductions(100) (see prim_file:get_drv_response/1) which means that processes writing to disk run out of their time slice in fewer function calls. This is of course to keep them from getting an unfair amount of CPU time. A logging process would probably therefore do well to fetch all messages in the message queue and write them using disk_log:alog_terms/2 (logging multiple messages each time). One could also possibly run the logger process at high priority. This means that normal priority process will have a hard time starving it. If the disk is slow, the logger process will yield while waiting for the disk (which won't block the runtime system as long as you have the thread pool enabled). In general, I think that processes that mainly dispatch messages, and don't generate any work on their own, should usually run on high priority. Otherwise, they tend to just contribute to delays in the system. /Uffe -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re[2]: [Haskell-cafe] Bringing Erlang to Haskell
Hello Tomasz, Tuesday, December 13, 2005, 12:49:04 PM, you wrote: TZ On Mon, Dec 12, 2005 at 04:00:46PM +, Joel Reymont wrote: One particular thing that bugs me is that I cannot really use TChan for thread mailboxes. I don't think I experienced this problem with Erlang but using a TChan with a logger thread quickly overwhelms the logger and fills the TChan and a lot (hundreds? thousands) of other threads are logging to it. TZ I wonder what Erlang does to solve this problem? Perhaps we should track TZ the number of unprocessed messages in TChans and the bigger it is TZ the more favor consumers over producers. even best - always prefer consumer to producer :) may be have two lists - one of threads waiting to consume, and one of threads waiting to produce? -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Substring replacements
Am Montag, 12. Dezember 2005 16:28 schrieben Sie:
From: Daniel Fischer [EMAIL PROTECTED]
To: Branimir Maksimovic [EMAIL PROTECTED]
CC: Haskell-Cafe@haskell.org
Subject: Re: [Haskell-cafe] Substring replacements
Date: Mon, 12 Dec 2005 16:15:46 +0100
Earlier today:
Sorry, but
Prelude SearchRep searchReplace abaaba ## abababaaba
abababaaba
I haven't analyzed the algorithm, so I don't know why exactly this
fails.
I'll take a look sometime soon.
I found the problem (one at least).
Say the pattern to be replaced begins with 'a' and we have a sufficiently
long
match with the pattern starting at the first 'a' in the String. Upon
encountering the second 'a', while the first pattern still matches, you
start
pushing onto the rollback-stack. But that isn't inspected anymore, so if
the
actual occurence of the pattern starts at the third (or fourth, n-th)
occurence of 'a' and that is already pushed onto the rollback, you miss
it.
I've corrected this with adjusting rollback position. if rollBack is null
then
search for rollback starts at second character if not starts at same as
searhed
character because I skip what was searched. That's all.
Though I'm not so sure now when I read this.
Still not working:
*New searchReplace abababc # ababababababc
ababababababc
*New searchReplace1 abababc # ababababababc
ababababababc
So the question is, can we find a cheap test to decide whether to use KMP
or
Bulat's version?
In real world situation your KMP will always be fastest on average.
I like that we are not using C arrays as then we have advantage
of lazyness and save on memory usage. C++ program will be faster
on shorter strings but on this large strings will loose due memory
latency. and with your test, both programs are very fast.
Greetings, Bane.
On my 256MB RAM AMD Duron 1200 MHz, Bulat's version is consistently about 20%
faster than my KMP on your test -- btw, I unboxed the pat array, which gave a
bit of extra speed, but not much.
And apologies to Sebastian Sylvan, I also included an unboxed version of bord,
built from the boxed version, and that sped things further up -- not much,
again, but there it is.
I wonder about this difference, -10% on one system and +20% on another system,
ist that normal?
Cheers, Daniel
--
Up-To-Date version of KMP:
import Data.Array.Unboxed (UArray, listArray, (!))
import qualified Data.Array as A (array, (!), elems)
searchReplace :: String - String - String - String
searchReplace _ str = str
searchReplace src@(c:cs) dst str = process 0 str
where
len = {-# scc len #-} length src
pat :: UArray Int Char
pat = {-# scc pat #-} listArray (0,len-1) src
bord ={-# scc bord #-} A.array (0,len) $ (0,-1):(1,0):
[(i+1,getBord (pat!i) i + 1) | i - [1 .. len-1]]
getBord s n
| m 0 = m
| s == pat!m = m
| otherwise = getBord s m
where
m = bord A.! n
bor :: UArray Int Int
bor = listArray (0,len) $ A.elems bord
getBor s n
| m 0 || s == pat!m = m
| otherwise = getBor s m
where
m = bor!n
process n str _ | n = len = {-# scc process #-} dst ++ process 0 str
process _ mat = {-# scc process #-} reverse mat
process 0 (s:st) _
| s == c= {-# scc process #-} process 1 st [s]
| otherwise = {-# scc process #-} s:process 0 st
process n str@(s:st) mat
| s == pat!n = {-# scc process #-} process (n+1) st (s:mat)
| otherwise = {-# scc process #-}
let j = getBor s n
(ret,skip) = splitAt j mat
in if j 0 then reverse mat ++ process 0 str
else reverse skip ++ process (j+1) st (s:ret)
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[Haskell-cafe] The Price of Performance
I thought this would be of interest to the Haskell community: http://www.acmqueue.com/modules.php?name=Contentpa=showpagepid=330 The ever-growing popularity of small multiprocessors is exposing more programmers to parallel hardware. More tools to spot correctness and performance problems are becoming available (e.g., thread checkers8 and performance debuggers9). Also, a few expert programmers can write efficient threaded code that is in turn leveraged by many others. Fast-locking and thread-efficient memory allocation libraries are good examples of programming work that is highly leveraged. Viva le STM! -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re[2]: [Haskell-cafe] Bringing Erlang to Haskell
Hello Joel, Tuesday, December 13, 2005, 1:05:10 PM, you wrote: are you read dewscription of my own Process library in haskell maillist? JR No. Can you give me a pointer? i will forward it to you. it have meaning to be subcribed there, just to see interesting announcements btw, i suggested you to try not using logging thread entirely, making all logging actions synchronously JR I cannot. Only one thread can use stdout, otherwise the output is JR garbled. Plus, combing through a few thousand individual files JR produced by the threads would be a pain. :))) import Control.Concurrent import Control.Monad import System.IO import System.IO.Unsafe main = do h - openBinaryFile test WriteMode for [1..100] $ \n - forkIO $ for [1..] $ \i - logger h (thread ++show n++ msg ++show i) getLine hClose h lock = unsafePerformIO$ newMVar () logger h msg = withMVar lock $ const$ do hPutStrLn h msg putStrLn msg for = flip mapM_ -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Fwd: [Haskell] ANNOUNCE: Process library (for dataflow-oriented programming?)
This is a forwarded message From: Bulat Ziganshin [EMAIL PROTECTED] To: haskell@haskell.org Date: Thursday, December 08, 2005, 1:36:05 AM Subject: [Haskell] ANNOUNCE: Process library (for dataflow-oriented programming?) ===8==Original message text=== Hello haskell, Joel's program (discussed in cafe), which now uses MVars instead of Channels to send data between threads, may be a good example of dataflow-driven program: it consists of many hundreds of threads and when one thread sends data to another through MVar, this thread in most cases goes to sleep until receiving thread will process previous value of this MVar. so, threads are waked up and asleep according to passing values between them, and the whole program executes in order defined by these data dependencies, as opposite to the order of program statements one year ago i developed small library, which can be helpful if you want to use such style of programming. its ideas are modelled after Unix pipes, which are widely used to assemble complex data processing engines from simple details. really this library is very thin layer over direct using of forkOS, channels and MVars; nevertheless, is is very convenient and beatiful you can download library as http://freearc.narod.ru/Process.tar.gz this page also contains sources of my program where you can find examples of using library in real toy :) below is a guide to library usage to create pipe, which contains 3 processes - producer, transformer and consumer: runP ( producer | transformer | consumer ) each process in pipe runned in separate Haskell thread. process is represented by ordinary Haskell function which gets an additional parameter - handle, which can be used to receive data from previous process in pipe (using receiveP) and send data to the next process (using sendP). for example, abovementioned processes can be implemented as: producer handle = mapM_ (sendP handle) [1..10] transformer handle = replicateM_ 10 $ do x - receiveP handle sendP handle (x*2) consumer handle = replicateM_ 10 $ do x - receiveP handle print x if first process in pipe tries to use receiveP or last process in pipe tries to use sendP, then run-time exception is generated. number of processes in pipe can be arbitrary. because each process is just ordinary Haskell function, you can add additional parameters to processes when constructing pipes: runP ( producer | multiple 2 | multiple 3 | consumer ) multiple n handle = replicateM_ 10 $ do x - receiveP handle sendP handle (x*n) moreover, you can construct pipe or part of it as ordinary data value, which then can be runned by runP: let pipe = case multipliers of [x] - multiple x [x,y] - multiple x | multiple y [x,y,z] - multiple x | multiple y | multiple z _ - \handle - fail Zero or too much multipliers runP ( producer | pipe | consumer ) there is also back channel, which can be used to return data to previous process in the pipe, its operations is send_backP and receive_backP. it can be used to return acknowledgments, synchronize processes or to return resources back. brief example of its usage: producer: sendP pipe (buf,len) consumer: ; ; (buf,len) - receiveP pipe ; hPutBuf file buf len ; send_backP pipe () receive_backP pipe ; --now we know that buf is free ; (i organized lines to show execution order) if processes joined in pipe with | then channel between them uses MVar, so at any moment it may contain no more than 1 element. if channel between two processes is created with | then Chan is used, which can contain arbitrary number of data items. be careful with such channels, because they can grow to unlimited size. | and | can be arbitrarily combined in one pipe: runP ( producer | multiple 2 | multiple 3 | consumer ) back channel (used by send_backP and receive_backP) are always multi-element (uses Chan) runP returns when all processes in pipe are finished. if any process in pipe generates uncaught exception, then all processes in pipe are killed and this exception is re-raised in thread called runP pipe or single process can also be runned in background using runAsyncP: handle - runAsyncP (multiple 2) handle returned here can be used to interact with first and last processes in pipe, in contrast to runP: handle - runAsyncP (multiple 2) sendP handle 1 res - receiveP handle of course, pipe runned asynchronously is not required to perform input, output, or both: handle - runAsyncP ( producer | transformer ) handle - runAsyncP ( transformer | consumer ) handle - runAsyncP ( producer | transformer | consumer ) currently channels to
Re: Re[2]: [Haskell-cafe] Bringing Erlang to Haskell
Thank you Bulat, makes total sense. This list is a treasure trove of a resource. I guess this is what happens when you go from Erlang to Haskell :-). I'm conditioned to think of everything as a process and uses processes for everything. On Dec 13, 2005, at 11:17 AM, Bulat Ziganshin wrote: import Control.Concurrent import Control.Monad import System.IO import System.IO.Unsafe main = do h - openBinaryFile test WriteMode for [1..100] $ \n - forkIO $ for [1..] $ \i - logger h (thread ++show n++ msg ++show i) getLine hClose h lock = unsafePerformIO$ newMVar () logger h msg = withMVar lock $ const$ do hPutStrLn h msg putStrLn msg for = flip mapM_ -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [Haskell] ANNOUNCE: Process library (for dataflow-oriented programming?)
Bulat, How is your library licensed? How can a process maintain internal state? How would I use your library to code a socket reader/writer that writes received events to the socket and propagates back anything that is received? The producer/consumer in front of this network client would be another process that analyzes the events sent back to it and produces events based on the analysis. How would I use it to launch a few network clients that seat there and process events until they decided to quit? The whole program needs to stay up until the last network client has exited. The pipeline to me looks like this: - Bot - Socket client ... Server / Bot launcher --- - Bot - Socket client ... Server \ - Bot - Socket client ... Server Where bot launcher starts a predefined # of bots and collects results sent back by each one. I think your library looks a bit like Yampa in that your processes are somewhat like signal functions. Thanks, Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Substring replacements
From: Daniel Fischer [EMAIL PROTECTED] To: Branimir Maksimovic [EMAIL PROTECTED] CC: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Substring replacements Date: Tue, 13 Dec 2005 11:23:29 +0100 Am Montag, 12. Dezember 2005 16:28 schrieben Sie: From: Daniel Fischer [EMAIL PROTECTED] To: Branimir Maksimovic [EMAIL PROTECTED] CC: Haskell-Cafe@haskell.org Subject: Re: [Haskell-cafe] Substring replacements Date: Mon, 12 Dec 2005 16:15:46 +0100 Earlier today: Sorry, but Prelude SearchRep searchReplace abaaba ## abababaaba abababaaba I haven't analyzed the algorithm, so I don't know why exactly this fails. I'll take a look sometime soon. I found the problem (one at least). Say the pattern to be replaced begins with 'a' and we have a sufficiently long match with the pattern starting at the first 'a' in the String. Upon encountering the second 'a', while the first pattern still matches, you start pushing onto the rollback-stack. But that isn't inspected anymore, so if the actual occurence of the pattern starts at the third (or fourth, n-th) occurence of 'a' and that is already pushed onto the rollback, you miss it. I've corrected this with adjusting rollback position. if rollBack is null then search for rollback starts at second character if not starts at same as searhed character because I skip what was searched. That's all. Though I'm not so sure now when I read this. Still not working: *New searchReplace abababc # ababababababc ababababababc *New searchReplace1 abababc # ababababababc ababababababc Yes, perhaps you've missed another post of mine. I've noticed that problem when pattern repeats more then 2 times and gave up because now whatever I do, your version is always fastest. So the question is, can we find a cheap test to decide whether to use KMP or Bulat's version? Just interleave string with search hits with one with no seacrh (that means partial too) hits, and your version will gain in speed. More partial matches and full search matches Bulat's version will gain in speed. Longer search strings, your version will have gains. In real world situation your KMP will always be fastest on average. I like that we are not using C arrays as then we have advantage of lazyness and save on memory usage. C++ program will be faster on shorter strings but on this large strings will loose due memory latency. and with your test, both programs are very fast. Greetings, Bane. On my 256MB RAM AMD Duron 1200 MHz, Bulat's version is consistently about 20% faster than my KMP on your test -- btw, I unboxed the pat array, which gave a bit of extra speed, but not much. I think that's because on your machine Bulat's version have better perfromance with CPU cache. I don;t know but now your version is 25% faster with my test on P4 hyperthreaded. your new version: $ time srchrep.exe Working:seasearch replace able seaseasearch baker seasearch charlie True Done real0m8.734s user0m0.015s sys 0m0.000s Bulat's version: [EMAIL PROTECTED] ~/tutorial $ time replace1.exe Working:seasearch replace able seaseasearch baker seasearch charlie True Done real0m11.734s user0m0.015s sys 0m0.015s 3 secs difference now. And apologies to Sebastian Sylvan, I also included an unboxed version of bord, built from the boxed version, and that sped things further up -- not much, again, but there it is. On my machine you got another 10-15% of boost with unboxed arrays. I wonder about this difference, -10% on one system and +20% on another system, ist that normal? Different caching schemes on CPU's perhaps? different memory latencies? hyperthreading helps your version? more code and data, perhaps because of that it pays the price on your machine? Greetings, Bane. _ Don't just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] trick to easily generate Eq/Ord instances
On Mon, 12 Dec 2005, Bulat Ziganshin wrote:
Hello
sometimes, Eq/Ord classes can't be derived automatically because we
need to comare only part of fields. in such situations i use the
following trick to easify generation of class instances:
data ArchiveBlock = ArchiveBlock {
blArchive :: Archive
, blType:: BlockType
, blCompressor :: Compressor
, blPos :: Integer
, blOrigSize:: Integer
, blCompSize:: Integer
, blCRC :: CRC
, blFiles :: Int
}
instance Eq ArchiveBlock where
(==)= map2eq $ map3 (blArchive,blPos,blCRC)
instance Ord ArchiveBlock where
compare = map2cmp $ map2 (blArchive,blPos)
{-
instance Ord ArchiveBlock where
compare = map2cmp blPos -- for comparision on just one field
-}
I solved that problem with two generic functions:
Compare the same item of two records.
compareField :: Ord b = (a - b) - a - a - Ordering
compareField f x y = compare (f x) (f y)
Lexicographically compare a list of attributes of two records.
compareRecord :: [a - a - Ordering] - a - a - Ordering
compareRecord cs x y =
head (dropWhile (EQ==) (map (\c - c x y) cs) ++ [EQ])
Use it this way:
instance Ord ArchiveBlock where
compare =
compareRecord
[compareField blArchive,
compareField blPos,
compareField blCRC]
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Re: [Haskell-cafe] Re: Bringing Erlang to Haskell
BTW, there has already been some work in this area. http://www-i2.informatik.rwth-aachen.de/~stolz/dhs/ http://www.informatik.uni-kiel.de/~fhu/PUBLICATIONS/1999/ifl.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re[2]: [Haskell] ANNOUNCE: Process library (for dataflow-oriented programming?)
Hello Joel,
Tuesday, December 13, 2005, 3:04:11 PM, you wrote:
JR How is your library licensed?
is costs many megabucks because it's very complex proprietary design
where some functions reach whole 12 lines! :)
of course, you can do what you want with this library. may be the
better way is to write your won, stealing one ot two ideas from mine
you can find another interesting works in:
http://www-i2.informatik.rwth-aachen.de/~stolz/Haskell/CA.hs
http://www-i2.informatik.rwth-aachen.de/Research/distributedHaskell/pbdhs-2001-09-20.tar.gz
(this one seems to be especially interesting for you, providing
ports - i think, in Erlang style)
http://www-i2.informatik.rwth-aachen.de/Research/distributedHaskell/network.tar.gz
http://quux.org/devel/missingh/missingh_0.12.0.tar.gz
(see Logging, Network, Threads directories)
JR How can a process maintain internal state?
process in my lib is just an ordinary Haskell function and therefore
this is done as in any other Haskell functions :)
my examples are easified - to not bother with EOF i just organized in
each process a loop which sends and/or receives just 10 messages. in
my real program data sent between process are defined by structures
like this:
data Message = FileStarted String
| FileData String
| DataEnd
so typical communication scenario is:
sendP h (FileStart 1)
; sendP h (FileData abc)
; sendP h (FileData def)
; sendP h (FileData ghi)
sendP h (FileStart 2)
; sendP h (FileData qwer)
sendP h (FileStart 3)
; sendP h (FileData 123)
sendP h DataEnd
and each function realizing process finishes only when this process is
done. sender process organizes cycle which reads files and sends their
data to the channel. receiver process organizes cycle until `DataEnd`
is received
in one phrase, it's just the same organization as in your own program
:)))
JR How would I use your library to code a socket reader/writer that
JR writes received events to the socket and propagates back anything
JR that is received?
JR The producer/consumer in front of this network client would be
JR another process that analyzes the events sent back to it and produces
JR events based on the analysis.
i don't understand your questions
JR How would I use it to launch a few network clients that seat there
JR and process events until they decided to quit? The whole program
JR needs to stay up until the last network client has exited.
JR The pipeline to me looks like this:
JR - Bot - Socket client ... Server
JR /
JR Bot launcher --- - Bot - Socket client ... Server
JR \
JR - Bot - Socket client ... Server
JR Where bot launcher starts a predefined # of bots and collects results
JR sent back by each one.
my lib is not appropriate for yor task, because it is oriented to
easify creation of processes which have only one input. but your main
thread must receive data from all bots, and bot must receive data from
two sources. the decision depends on the strategy of mixing these
inputs - will it be fair FIFO or more advanced schema?
if it's a FIFO then something like this (i'm skipped only exceptions
processing and creating socket-reader process inside of each bot -
writing to socket must be performed by bot itself):
{-# OPTIONS_GHC -cpp #-}
import Control.Concurrent
import Control.Exception
import Control.Monad
import Data.Array
import Data.Char
import Data.Either
import Data.HashTable
import Data.IORef
import Data.List
import Data.Maybe
import Data.Word
import Debug.Trace
import Foreign.C.String
import Foreign.Marshal.Alloc
import Foreign.Marshal.Array
import Foreign.Marshal.Pool
import Foreign.Marshal.Utils
import Foreign.Ptr
import Text.Regex
import System.IO.Unsafe
-
--- Bot launcher implementation -
-
main = do
(sendToMain, receiveFromBots) - createChannel
bots - foreach [1..10] $ createProcess . bot sendToMain
mapM_ (`sendToProcess` Wake up, Neo!) bots
while receiveFromBots (/=I want to stop the Matrix!) print
--
mapM_ killProcess bots
-- or, if you are more humane - mapM_ waitProcessDie bots :)
-
--- Bot implementation --
-
bot sendToMain n receiveMessagesForMe = do
forever $ do
x - receiveMessagesForMe
case x of
Wake up, Neo! - sendToMain$ show n++: I'm not sleeping!
Are you wanna coffee? - sendToMain$ show n++: Yes, it is!
yield
sendToMain I want to stop the Matrix!
-
--- Process implementation details --
-
-- |Abstract type for all of
[Haskell-cafe] FreeBSD: Max # of sockets opened
Folks, I need some help from those of you with a FreeBSD box. It looks like 'ulimit -n' on FreeBSD lets you have 10k+ file descriptors open per process. FD_SETSIZE is 1024 in the system headers, though. GHC relies on this value (see ghc/rts/Select.c). Normally, you will get the EMFILE error if you try to open more sockets than what is allowed with 'ulimit -n'. If you allow yourself more than 1024 descriptors per process then you do not get this error but... This seems to lead to a situation where you open more than 1024 sockets and shortly afterwards get 'connection resets' for some or all of your sockets. Maybe just those above 1024, I have not determined this precisely. My question is this: is it possible to get a higher number of open sockets by editing the system header files on FreeBSD and recompiling GHC? Has anyone tried this before? How high can you go? Thanks, Joel -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Top-level TVars
Can this be done now or is this a GHC 6.5 feature? My combination of unsafePerformIO with atomically $ newTVar does not seem to be working. Thanks, Joel P.S. What is the ETA for 6.5? On Mon, Dec 05, 2005 at 10:50:13AM -, Simon Peyton-Jones wrote: It turns out to be easy to provide newTVarIO :: a - IO (TVar a) which you can call from inside 'unsafePerformIO'. That means you can allocate top-level TVars without fuss. -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FreeBSD: Max # of sockets opened
On Tue, 13 Dec 2005, Joel Reymont wrote: It looks like 'ulimit -n' on FreeBSD lets you have 10k+ file descriptors open per process. FD_SETSIZE is 1024 in the system headers, though. GHC relies on this value (see ghc/rts/Select.c). FD_SETSIZE is actually dynamic on FreeBSD (at least from the kernel's point of view - the macros are less so). You can re-set it to whatever value you like at compile time (e.g. gcc -DFD_SETSIZE=10240). Tony. -- f.a.n.finch [EMAIL PROTECTED] http://dotat.at/ BISCAY: WEST 5 OR 6 BECOMING VARIABLE 3 OR 4. SHOWERS AT FIRST. MODERATE OR GOOD. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FreeBSD: Max # of sockets opened
So it's just a matter of recompiling GHC and have it pick up new values? On Dec 13, 2005, at 6:11 PM, Tony Finch wrote: FD_SETSIZE is actually dynamic on FreeBSD (at least from the kernel's point of view - the macros are less so). You can re-set it to whatever value you like at compile time (e.g. gcc -DFD_SETSIZE=10240). -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FreeBSD: Max # of sockets opened
On Tue, 13 Dec 2005, Joel Reymont wrote: So it's just a matter of recompiling GHC and have it pick up new values? Yes. (It's a pity that the FD_SET macros aren't run-time configurable.) Tony. -- f.a.n.finch [EMAIL PROTECTED] http://dotat.at/ BISCAY: WEST 5 OR 6 BECOMING VARIABLE 3 OR 4. SHOWERS AT FIRST. MODERATE OR GOOD. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Top-level TVars
On Tue, Dec 13, 2005 at 06:08:23PM +, Joel Reymont wrote: Can this be done now or is this a GHC 6.5 feature? My combination of unsafePerformIO with atomically $ newTVar does not seem to be working. Here is an example how you can initialize a top-level STM variable. http://www.uncurry.com/repos/TimeVar/TimeVar.hs It just forks a new thread inside unsafePerformIO, it runs atomically in it and passes the result through ordinary MVar. Best regards Tomasz -- I am searching for a programmer who is good at least in some of [Haskell, ML, C++, Linux, FreeBSD, math] for work in Warsaw, Poland ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Announcing Djinn, new version 2004-12-13
There is a new version of Djinn available, with two notable new features: Haskell data types can be defined and the found functions are sorted (heuristically) to present the best one first. To play with Djinn do a darcs get http://darcs.augustsson.net/Darcs/Djinn or get http://darcs.augustsson.net/Darcs/Djinn/Djinn.tar.gz Then just type make. (You need a Haskell 98 implementation and some libraries.) And then start djinn. `-- Lennart ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
