Re: [Haskell-cafe] Re: Binary IO of a list of ints
Stephan Walter wrote: Hi, On 2008-01-24 12:14, Jamie Love wrote: I have a list of ints, with values between 0 and 255 and I need to print them out in little endian form to a file. How about just using Data.Char.chr ? Essentially because I need to control the byte ordering, and it has to be in the current case the opposite to my computer's native ordering (the file is a binary file). Prelude let a = [32..64] :: [Int] Prelude map Data.Char.chr a !\#$%'()*+,-./0123456789:;=?@ --Stephan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe This message has been scanned for viruses and dangerous content by MailScanner and is believed to be clean. -- Jamie Love Senior Consultant Aviarc Australia Mobile: +61 400 548 048 This message has been scanned for viruses and dangerous content by MailScanner and is believed to be clean. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: binary IO
Hello Peter, Thursday, December 29, 2005, 5:58:29 PM, you wrote: PS The Fast I/O article I posted a few days ago is my PS unfinished attempt at writing an efficient, general-purpose PS binary I/O library for Haskell. where i can find it? -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: binary IO
Amen! Haskell has forever realigned my mind-gears and I'm observing positive results as we speak :-). On Dec 28, 2005, at 1:56 AM, Peter Simons wrote: Even if you ultimately decide to write your application in another language, you'll find that knowing and understanding Haskell will change the way you design software -- regardless of the language you use. -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: binary IO
I would compare Haskell to visiting the chiropractor. You will walk straighter, stand taller and your life will never be the same :D. On Dec 28, 2005, at 1:56 AM, Peter Simons wrote: you'll find that knowing and understanding Haskell will change the way you design software -- regardless of the language you use. -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: binary IO
Hello Peter, Tuesday, December 27, 2005, 11:26:29 PM, you wrote: PS My guess is that you would learn more if _you_ would plug PS the different IO libraries into your test code. I'm certain Peter, because you claimed that Haskell can be made as effective as C, please help us :) your BlockIO library is great, but it's usage is limited to very specific sutuations - when we can save pass state between processing of individual bytes what for (de)serialization tasks? my best attempts is still 10x slower than C version. can you roll up little prototype for such library or just sketch an ideas so i can try to implement it? it is also call to everyone - what is the key to efficient Binary lib? you can see my current attempt in http://freearc.narod.ru/Binary.tar.gz the key functions: instance (MemoryStream h) = ByteStream (BufferedMemoryStream h) where vPutByte mem@(Buf h buf' pos' end') byte = do pos - readPtr pos' end - readPtr end' if (pos==end) then do sendCurrentBuffer mem receiveNextBuffer mem vPutByte mem byte else do writePtr pos' $! (pos+:1) writeByteAt pos $! (fromEnum byte) vGetByte mem@(Buf h buf' pos' end') = do pos - readPtr pos' end - readPtr end' if (pos==end) then do sendCurrentBuffer mem receiveNextBuffer mem vGetByte mem else do writePtr pos' $! (pos+:1) byte - readByteAt pos return $! (toEnum byte) and series of getWordXX/putWordXX in class (ByteStream h) = BitStream h: putWord32 h w = do vPutByte h $! ( w `shiftR` 24) vPutByte h $! ((w `shiftR` 16) .. 0xff) vPutByte h $! ((w `shiftR` 8) .. 0xff) vPutByte h $! ( w .. 0xff) getWord32 h = do w1 - vGetByte h w2 - vGetByte h w3 - vGetByte h w4 - vGetByte h return $! ((w1 `shiftL` 24) .|. (w2 `shiftL` 16) .|. (w3 `shiftL` 8) .|. (w4)) -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: binary IO
I will have to leave this for a while. I apologize but I'm more than a bit frustrated at the moment and it's not fair of me to take it out on everybody else. If someone is willing to take this further I will appreciate it, otherwise I'll get to it in the coming weeks. Besides knowing how to do it better I would like to know why it works poorly as it is. So it's gonna take me a while. Thanks, Joel On Dec 27, 2005, at 8:26 PM, Peter Simons wrote: My guess is that you would learn more if _you_ would plug the different IO libraries into your test code. I'm certain the respective library authors will be quite happy to answer questions and to investigate unexpected results. -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
