Re: [Haskell-cafe] Parsing words with parsec
On 3/30/07, Stefan O'Rear [EMAIL PROTECTED] wrote: On Fri, Mar 30, 2007 at 05:43:34AM +0200, paolino wrote: Hi, I had a bad time trying to parse the words of a text. I suspect I miss some parsec knowledge. I'd start by not sextuple-posting, it just sextuples the ugliness ;-) Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. import Char( isAlpha ) import List( groupBy ) equating f x y = f x == f y -- in Data.Eq, iff you have GHC 6.7 isLetter x = isAlpha x || x == '_' || x == '@' myWords = filter (isLetter . head) . groupBy (equating isLetter) Testing your code, it misses the words with numbers inside exclusion and uses the number as separators. !runhaskell prova.hs [[EMAIL PROTECTED],sara,mimmo,ab,a,b,ab,cd] Thanks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] sending from Gmail (was Parsing words with parsec)
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paolino I'd start by not sextuple-posting, it just sextuples the ugliness ;-) Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. Are you expecting to see your sent message eventually arrive in your inbox? gmail doesn't do that by default (and I don't see an obvious setting to change it). gmail seems to be fairly keen on removing duplicate messages. Alistair * Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. * ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] sending from Gmail (was Parsing words with parsec)
On Friday 30 March 2007 11:44, Bayley, Alistair wrote: From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paolino I'd start by not sextuple-posting, it just sextuples the ugliness ;-) Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. Are you expecting to see your sent message eventually arrive in your inbox? gmail doesn't do that by default (and I don't see an obvious setting to change it). gmail seems to be fairly keen on removing duplicate messages. Then probably I was expecting haskell-cafe to send messages sent by me to me also so I can have my messages in the thread automatically. Or , I have to copy them from the sent box to the haskell-cafe filter box ? I'm confused. Paolino ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] sending from Gmail (was Parsing words with parsec)
On 30/03/07, Bayley, Alistair [EMAIL PROTECTED] wrote: Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. Are you expecting to see your sent message eventually arrive in your inbox? gmail doesn't do that by default (and I don't see an obvious setting to change it). gmail seems to be fairly keen on removing duplicate messages. The ML software has the option of not sending you your own messages, but I can't remember if it is on by default or not. Cheers, Dougal. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] sending from Gmail (was Parsing words with parsec)
On Friday 30 March 2007 11:54, Dougal Stanton wrote: On 30/03/07, Bayley, Alistair [EMAIL PROTECTED] wrote: Mhh, still I don't see any them in my inbox mails , probably something buggy in gmail configuration, sorry :/. Are you expecting to see your sent message eventually arrive in your inbox? gmail doesn't do that by default (and I don't see an obvious setting to change it). gmail seems to be fairly keen on removing duplicate messages. The ML software has the option of not sending you your own messages, but I can't remember if it is on by default or not. Just controlled , it's set to Yes on receiving copy of my posts. Thanks anyway. Paolino ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Monad/Functor Book
Dave-86 wrote: Given the amount of material posted at haskell.org and elsewhere explaining IO, monads and functors, has anyone considered publishing a comprehensive book explaining those subjects? (I am trying to read all the material online, but books are easier to read and don't require sitting in front of a computer to do so. Plus I can write in books :-). ) Thanks, Dave Feustel ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe Print out the wikibook [1]? IMO it has good coverage of Monads, more detailed than any of the textbooks I've read, and leads into CT and advanced topics that aren't really covered in any of the books (partly because a lot of it isn't Haskell 98 of course). [1] http://en.wikibooks.org/wiki/Haskell -- View this message in context: http://www.nabble.com/Monad-Functor-Book-tf3474082.html#a9752877 Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Compiling GHC
On Fri, Mar 30, 2007 at 04:36:32PM +1000, Chris Witte wrote: I'm tying to compile GHC under mingw (winxp with mingw no cygwin), Loading package base ... linking ... ghc.exe: unable to load package `base' ghc.exe: C:/msys/1.0/local/HSbase.o: unknown symbol `_gettimeofday' any ideas on what could be causing this. What does grep -i gettimeofday mk/config.h say? If HAVE_GETTIMEOFDAY is defined then either comment it out (between running configure and running make), or work out why the configure test is succeeding but it doesn't work when GHC tries to use it. Thanks Ian ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Data.ByteStream.Char8.words performance
I noticed something about ByteStream performance that I don't understand. I have a test text document: $ ls -sh test-text-file 956K test-text-file Running this program, using the Prelude's IO functions: module Main where main = do content - readFile test-text-file let l = length . words $ content print l I get: $ time ./a.out 174372 real0m0.805s user0m0.720s sys 0m0.008s Running a version of the same thing using Data.ByteStream.Char8: module Main where import qualified Data.ByteString.Char8 as B main = do content - B.readFile test-text-file let l = length . B.words $ content print l I see a time that is quite a bit slower: $ time ./a.out 174372 real0m1.864s user0m1.596s sys 0m0.012s Changing it to incorporate similar code to the implementation of B.words: module Main where import qualified Data.ByteString.Char8 as B import Data.Char (isSpace) main = do content - B.readFile test-text-file let l = length $ filter (not . B.null) $ B.splitWith isSpace content print l I see a similar time as with B.words: $ time ./a.out 174372 real0m1.835s user0m1.628s sys 0m0.012s And then if I change this to use B.split ' ' instead of isSpace: module Main where import qualified Data.ByteString.Char8 as B main = do content - B.readFile test-text-file let l = length $ filter (not . B.null) $ B.split ' ' content print l I get a time that's much more reasonable-looking, compared to the original Prelude.words version: $ time ./a.out 174313 real0m0.389s user0m0.312s sys 0m0.004s It seems like the B.splitWith isSpace code is really slow for some reason. Anybody have any idea what's going on? The actual implementation is using isSpaceWord8 which is a case statement looking for a pile of different whitespace characters. -- .~.Dino Morelli /V\email: [EMAIL PROTECTED] /( )\ irc: dino- ^^-^^ preferred distro: Debian GNU/Linux http://www.debian.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.ByteStream.Char8.words performance
Hello, Did you compile with -O2 ? That makes a huge difference when using ByteString. j. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Lambdabot not running on XP
On 29 Mar 2007 at 15:18, Stefan O'Rear wrote: On Thu, Mar 29, 2007 at 08:29:51PM +0100, Iain Alexander wrote: [snip] (ghc-6.4.1, lambdabot-4.0, WinXP SP2) As a result of my recentish code cleanups, everything lambdabot does, even the main command loop, is a @-command. If you just run it as 'lambdabot', you give it zero commands, so it loads all plugins, executes zero commands, and quits. I suppose I could make the command loop the default, but that is just too ugly since as it stands the core doesn't know the command loop even exists. You want 'lambdabot -e offline' or 'lambdabot -e rc online.rc'. Note that none of this applies if you are using the tarball. Usage: lambdabot [--online|--restricted] (As I said, I'm using lambdabot-4.0) -- Iain Alexander [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.ByteStream.Char8.words performance
On Fri, 30 Mar 2007, Jeremy Shaw wrote: Hello, Did you compile with -O2 ? That makes a huge difference when using ByteString. j. Ah, that was exactly it. I feel silly. module Main where import qualified Data.ByteString.Char8 as B main = do content - B.readFile test-text-file let l = length . B.words $ content print l $ ghc -O2 count-b.hs $ time ./a.out 174372 real0m0.198s user0m0.136s sys 0m0.012s Much faster. Thank you! dino- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.ByteStream.Char8.words performance
On Fri, 2007-03-30 at 14:24 -0700, Jeremy Shaw wrote:
Hello,
Did you compile with -O2 ? That makes a huge difference when using ByteString.
Hmm, I think we can do better than that. It would be nicer to have it
work fast without needing any -O flags at all in the user's module.
Lets look at the current def again:
words :: ByteString - [ByteString]
words = P.filter (not . B.null) . B.splitWith isSpaceWord8
{-# INLINE words #-}
So this will always inline words into your program (when using -O or
-O2) however there is nothing really to be gained from doing that.
There's no fusion going on here, it's always going to (lazily) allocate
the result list.
So I think it's probably better to just remove the inline pragma. In
fact Dino's original program might work faster with -O0 than -O1. :-)
The best you could do with the current definition (rather than writing a
specialised implementation) is something like:
words = P.filter (not . B.null) . words'
{-# INLINE words #-}
words' = B.splitWith isSpaceWord8
{-# NOINLINE words' #-}
since the filter could fuse in the calling context with a good list
consumer but the B.splitWith is not a good producer in it's current
definition so there is no benefit to inlining it. All that gives you is
the potential to compile it badly in the calling module rather than just
calling the single compiled version in the ByteString lib (that was of
course built with -O2).
The ByteString libs was more-or-less the first high performance thing
that we wrote and we've learnt plenty more since then. I think there's a
good deal more performance too eek out of it yet, both at the low and
high level.
Duncan
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