Re: [Haskell-cafe] Why am I not allowed to use CStringLen inforeignexport?
Thanks a lot for this information it helped a lot. Because I use the VBA 6 version the string characters are supposed to be a byte so I changed your code to type BSTR8 = Ptr Word8 createBSTR8 :: String - IO BSTR8 createBSTR8 s = do let len :: Word32 = fromIntegral (length s) low_l :: Word8 = fromIntegral (len .. 0x) low_h :: Word8 = fromIntegral (shiftR len 8 .. 0x) high_l :: Word8 = fromIntegral (shiftR len 16 .. 0x) high_h :: Word8 = fromIntegral (shiftR len 24 .. 0x) arr - newArray ([low_l,low_h,high_l,high_h] ++ map (fromIntegral . fromEnum) s ++ [0]) return $! plusPtr arr 4 Maybe this helps some one else too. I am thinking about creating a wikipage about Haskell-VBA interfacing through a DLL. Is it okay for you if I put your code there? I am a bit concerned about the memory. newArray states that the memory has to be freed after usage. Is this needed here? How can it be done? Thanks to everyone who responded, Andreas - Original Message - From: Brian Hulley [EMAIL PROTECTED] To: Andreas Marth [EMAIL PROTECTED]; haskell-cafe@haskell.org Sent: Friday, September 15, 2006 10:07 PM Subject: Re: [Haskell-cafe] Why am I not allowed to use CStringLen inforeignexport? Brian Hulley wrote: I assume that this means that on 32 bit Windows, the format of a BSTR is: Word16 -- low word of length Word16 -- high word of length Word16 -- first char of string ... The above is not quite correct. It appears from http://www.oreilly.com/catalog/win32api/chapter/ch06.html that the length must preceed the actual BSTR, thus you must give VBA a pointer to the first *char* in the string not the actual start of the array of Word16's in memory. Furthermore, it appears that a terminating NULL is still needed even though the string itself can contain NULL characters. No only that, but the length must be given as the number of *bytes* (excluding the terminating NULL) not the number of characters. Therefore here is a revised attempt at creating a Win32 BSTR: import Data.Word import Data.Bits import Foreign.Marshal.Array import Foreign.Ptr type BSTR = Ptr Word16 createBSTR :: [Char] - IO BSTR createBSTR s = do let len :: Word32 = fromIntegral (length s * 2) low :: Word16 = fromIntegral (len .. 0x) high :: Word16 = fromIntegral (shiftR len 16 .. 0x) arr - newArray ([low, high] ++ map (fromIntegral . fromEnum) s ++ [0]) return $! plusPtr arr 4 foreign export stdcall hello :: IO BSTR hello :: IO BSTR hello = createBSTR Hello world! Regards, Brian. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [newbie] How to test this function?
Bruno Martínez [EMAIL PROTECTED] writes: On Thu, 21 Sep 2006 15:12:07 -0300, Benjamin Franksen [EMAIL PROTECTED] wrote: OK. Thanks. I didn't find that one because it's not offered as an identation option in emacs haskell mode. Emacs is evil! That's a great exaggeration I'm open to alternatives. I use Windows, so went out of the way to have emacs. What do you use? I don't care much for colors, but automatic identation is very handy (when it works :D). If there's a problem with haskell emacs mode, it seems very likely that if you ask the maintainer nicely, he'll do something about it. See http://www.iro.umontreal.ca/~monnier/elisp/#haskell-mode -- Jón Fairbairn [EMAIL PROTECTED] http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2006-09-13) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell DLL crashes Excel
Hi everybody!
As you might now already know I try to let VBA call Haskell via a DLL. The
function returns a String. Everything works fine now if I call the function
only once. If I call it more often Excel crashes soon. Does any body have
any idea what is going wrong or how I can find out. (I am a medium skilled
Haskell user but no VBA programmer.)
My code for Haskell (Calculate.hs):
module Calculate where
import Foreign.C.String (CString, peekCString, newCString)
import Data.Word (Word8, Word16, Word32)
import Data.Bits (shiftR, (..))
import Foreign.Marshal.Array (newArray)
import Foreign.Ptr (Ptr, plusPtr)
type BSTR8 = Ptr Word8
createBSTR8 :: String - IO BSTR8
createBSTR8 s = do
let
len :: Word32 = fromIntegral (length s)
low_l :: Word8 = fromIntegral (len .. 0x)
low_h :: Word8 = fromIntegral (shiftR len 8 .. 0x)
high_l :: Word8 = fromIntegral (shiftR len 16 .. 0x)
high_h :: Word8 = fromIntegral (shiftR len 24 .. 0x)
arr - newArray ([low_l,low_h,high_l,high_h] ++ map (fromIntegral .
fromEnum) s ++ [0])
return $! plusPtr arr 4
testL :: Int - CString - IO BSTR8
testL n cs = do s - peekCString cs
createBSTR8 $ concat $ take n $ repeat s
foreign export stdcall testL :: Int - CString - IO BSTR8
---
My VBA code (in Excel 2000):
Option Explicit
Dim h1 As String
Dim a As Long
Dim b As Long
Private Declare Function testL Lib P:\Daten\Code\Calculate.dll (ByVal n As
Long, ByVal str As String) As String
Sub Test()
a = 0
b = 10
h1 =
Do While a = 15
h1 = testL(b, What is going on here?)
a = a + 1
Debug.Print a
Debug.Print h1
Loop
End Sub
---
And my DllMain.c:
#include windows.h
#include Rts.h
extern void __stginit_Calculate(void);
static char* args[] = { ghcDll, NULL };
/* N.B. argv arrays must end with NULL */
BOOL
STDCALL
DllMain
( HANDLE hModule
, DWORD reason
, void* reserved
)
{
if (reason == DLL_PROCESS_ATTACH) {
/* By now, the RTS DLL should have been hoisted in, but we need to
start it up. */
startupHaskell(1, args, __stginit_Calculate);
return TRUE;
}
if (reason == DLL_PROCESS_DETACH) {
shutdownHaskell();
return TRUE;
}
return TRUE;
}
And I compile the DLL with:
ghc -c --make -fglasgow-exts -static Calculate.hs
ghc -c -fglasgow-exts -static *.c
ghc --mk-dll -o Calculate.dll *.o -static -optdll--def -optdllCalculate.def
--
Nearly forgot Calculte.def:
LIBRARY Calculate
EXPORTS
testL = [EMAIL PROTECTED]
-
The DLL is stable regarding the length of the input string and thelength of
the return string (determined with b).
But crashes for larger(?) a's. At my computer it crashes with a 9.
There seems to be a connection between b and a. If b is 10 then a9 crashes
a10 is fine.
If b=1000 then a5 is okay a4 crashes.
If b =100 then a5 is okay, a5 crashes and a=5 crashes with an error
Statement in 0x778cb032 points to 0x the function 'written' could
not be done ... And a second one Statement in 0x778cc441 points to
0x the function 'written' could not be done ... (My translation of
the german errors.)
If anybody knows what is going wrong or can give me a hint how to find out
what is going wrong it would be very helpful.
Thanks Andreas
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Re: [Haskell-cafe] Haskell DLL crashes Excel
Andreas Marth wrote: type BSTR8 = Ptr Word8 createBSTR8 :: String - IO BSTR8 createBSTR8 s = do let len :: Word32 = fromIntegral (length s) low_l :: Word8 = fromIntegral (len .. 0x) low_h :: Word8 = fromIntegral (shiftR len 8 .. 0x) high_l :: Word8 = fromIntegral (shiftR len 16 .. 0x) high_h :: Word8 = fromIntegral (shiftR len 24 .. 0x) arr - newArray ([low_l,low_h,high_l,high_h] ++ map (fromIntegral . fromEnum) s ++ [0]) return $! plusPtr arr 4 Use SysAllocString... family. Also, remember they (by convention) have to be released from the client side. Cheers, Kyra ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [newbie] How to test this function?
If there's a problem with haskell emacs mode, it seems very likely that if you ask the maintainer nicely, he'll do something about it. See http://www.iro.umontreal.ca/~monnier/elisp/#haskell-mode I asked Stefan a while ago: I like your Emacs mode but it behaves a bit oddly when trying to indent if/then/else expressions in do notation. Typing tab only gives me one possible indentation, like so: do if True then foo else bar That is, the then and else branches line up under the if which is an error according to Haskell's layout rule. It probably should indent them like case with the then lining up with the condition to the if. I'd fix it myself if I knew Lisp but I don't. :/ Yes, it's a (recently) known problem which I haven't fixed yet. It's in the indent.hs test-suite, with a FIXME :-( ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskore
On Fri, 22 Sep 2006, David Curran wrote: Hi I have been trying to learn haskell (tip over the vending machine) for a while and eventually decided the Haskore music library might be a good way to start understating the language. Please, don't understate this language! ;-) I am using windows and hugs98. The IOExtensions.hs file will not work under windows. Any ideas on how to make it work or is this library *nix only? I think that this problem was resolved in the revised Haskore version, see http://darcs.haskell.org/haskore/ and its binary file wrapper http://darcs.haskell.org/haskore/src/Haskore/General/IO.hs However, I feel that this Haskore version is no longer simple enough for learning. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell DLL crashes Excel
Kyra wrote: Use SysAllocString... family. Also, remember they (by convention) have to be released from the client side. Oops, they = such allocated BSTRs. Cheers, Kyra ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: [newbie] How to test this function?
Johan Tibell [EMAIL PROTECTED] writes: If there's a problem with haskell emacs mode, it seems very likely that if you ask the maintainer nicely, he'll do something about it. See http://www.iro.umontreal.ca/~monnier/elisp/#haskell-mode I asked Stefan a while ago: I like your Emacs mode but it behaves a bit oddly when trying to indent if/then/else expressions in do notation. Typing tab only gives me one possible indentation, like so: do if True then foo else bar That is, the then and else branches line up under the if which is an error according to Haskell's layout rule. It probably should indent them like case with the then lining up with the condition to the if. I'd fix it myself if I knew Lisp but I don't. :/ Yes, it's a (recently) known problem which I haven't fixed yet. It's in the indent.hs test-suite, with a FIXME :-( For that one, if it doesn't get mended for long enough, Haskell' might accept the present layout. http://hackage.haskell.org/trac/haskell-prime/wiki/DoAndIfThenElse -- Jón Fairbairn [EMAIL PROTECTED] http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2006-09-13) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskore
David Curran [EMAIL PROTECTED] writes: Hi I have been trying to learn haskell (tip over the vending machine) Tipping over a vending machine is a real world effect, so you'll have to use the IO Monad. -- Jón Fairbairn [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskore
Hello David, Friday, September 22, 2006, 1:40:31 PM, you wrote: openBinaryFile :: FilePath - IOMode - IO Handle import System.IO writeBinaryFile :: FilePath - String - IO () writeBinaryFile f txt = bracket (openBinaryFile f WriteMode) hClose (\hdl - hPutStr hdl txt) readBinaryFile :: FilePath - IO String readBinaryFile name = openBinaryFile name ReadMode = hGetContents these definitions will work both on unix and win -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskore
As Henning points out, the darcs version of Haskore is now the standard, which Henning has been kind enough to set up. However, it has also been extended and re-organized, and at least currently does not have the simplistic feel of the original Haskore. On the other hand, the version that is described in Chapter 20 of SOE (which is called "MDL") is very simple and elegant and would be a great way to "learn Haskell". Even though it's in Chapter 20, it depends only on material presented much earlier in the book. I hope this helps, -Paul Henning Thielemann wrote: On Fri, 22 Sep 2006, David Curran wrote: Hi I have been trying to learn haskell (tip over the vending machine) for a while and eventually decided the Haskore music library might be a good way to start understating the language. I am using windows and hugs98. The IOExtensions.hs file will not work under windows. Any ideas on how to make it work or is this library *nix only? I think that this problem was resolved in the revised Haskore version, see http://darcs.haskell.org/haskore/ and its binary file wrapper http://darcs.haskell.org/haskore/src/Haskore/General/IO.hs However, I feel that this Haskore version is no longer simple enough for learning. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskore microtonal support
An easier and better way to support microtonal music in Haskore is to use the csound back-end instead of MIDI. I'd be happy to help someone develop such a thing if interested. -Paul Magnus Jonsson wrote: On Thu, 14 Sep 2006, Henning Thielemann wrote: On Thu, 14 Sep 2006, Magnus Jonsson wrote: Now even more interestingly, my program also deals with music! :) I'm generating microtonal midi files. I use it for very much the same purpose as you do (although my program is not yet finished). Is it something we could and should add to Haskore? If Haskore could support microtones that would make this world a slightly better world for me. Here are the basic things you need to support microtonal music: - Pitch representations would have to be able to express any pitch. - One appealing approach is to represent a pitch directly as it's frequency. - Probably the most useful representation though is a base pitch, say one of C,D,E,F,G,A,B, followed by a list of accidentals that modify the pitch. The user should be able to define his own base pitches and accidentals, in terms of cents or frequency ratios or something similar. - Generating microtonal midi files requires that you add pitch-bend messages before all notes. That restricts each midi channel to only being able to play one note at a time. This is a big deficiency in the midi protocol imo. / Magnus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: Haskel DLL crashes Excel
Andreas Marth wrote: As you might now already know I try to let VBA call Haskell via a DLL. I had to do this a while ago; the best I could come up with was: 1. Make a Haskell DLL that exports plain C-style interface. 2. With Visual Studio, make a COM DLL that exports the interfaces to be used by VBA and passes the calls to the Haskell DLL. This COM DLL, among other things, handles the conversion between C-style strings and BSTR (there are examples on msdn.microsoft.com of doing this). Hope this helps. Cheers, Cyril ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Why am I not allowed to use CStringLen inforeignexport?
Andreas Marth wrote: Thanks a lot for this information it helped a lot. Glad to be of help. I am thinking about creating a wikipage about Haskell-VBA interfacing through a DLL. Is it okay for you if I put your code there? Yes. I am a bit concerned about the memory. newArray states that the memory has to be freed after usage. Is this needed here? How can it be done? One way could be to write a function which creates the BSTR, passes it to a function, then deallocates the BSTR before returning eg (untested): import Control.Exception (bracket) withBSTR8 :: [Char] - (BSTR8 - IO a) - IO a withBSTR8 s f = bracket (createBSTR8 s) (\bstr - free (bstr `plusPtr` (-4))) (\bstr - f bstr) Regards, Brian. -- Logic empowers us and Love gives us purpose. Yet still phantoms restless for eras long past, congealed in the present in unthought forms, strive mightily unseen to destroy us. http://www.metamilk.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
