Works fine here (Mac OS X 10.5):
MigMit:ngram MigMit$ ghc --make Main.hs srilm.o
[1 of 2] Compiling LM ( LM.hs, LM.o )
LM.hs:9:0: Warning: possible missing & in foreign import of FunPtr
[2 of 2] Compiling Main ( Main.hs, Main.o )
Linking Main ...
MigMit:ngram MigMit$ ls Main*
Main* Main.hi Main.hs Main.hs~ Main.o
MigMit:ngram MigMit$ cat Main.hs
module Main where
import LM(scoreSequence, buildLM)
main :: IO ()
main = do
let lm = buildLM 5 "eng.kn.5g.lm"
putStrLn $ show $ scoreSequence lm 5 ["the", "prime", "minister",
"gave","a", "speech", "."]
MigMit:ngram MigMit$ cat LM.hs
{-# INCLUDE "srilm.h" #-}
{-# LANGUAGE ForeignFunctionInterface, EmptyDataDecls #-}
module LM where
import Foreign
import Foreign.C
data Ngram
data NGModel = NGModel {ng :: !(ForeignPtr Ngram)}
foreign import ccall "srilm.h bldLM" c_blm :: CInt -> CString -> Ptr
Ngram
foreign import ccall "srilm.h deleteLM" c_dlm :: FunPtr ((Ptr Ngram) -
> IO ())
foreign import ccall "srilm.h getSeqProb" c_ngramProb :: Ptr Ngram ->
CString -> CUInt -> CUInt -> CFloat
scoreSequence :: NGModel -> Int -> [String] -> Float
scoreSequence ngram order seq =
unsafePerformIO $ do
stringSeq <- newCString (unwords seq)
let sc = c_ngramProb (unsafeForeignPtrToPtr $ ng ngram)
stringSeq (fromIntegral order) (fromIntegral $ length seq)
return (realToFrac sc)
buildLM :: Int -> String -> NGModel
buildLM order fname =
NGModel $
unsafePerformIO $ do
cFName <- newCString fname
let ng = c_blm (fromIntegral order) cFName
return $ unsafePerformIO $ newForeignPtr c_dlm ng
MigMit:ngram MigMit$ cat srilm.h
#ifdef __cplusplus
extern "C" {
class Ngram{};
#else
typedef struct Ngram Ngram;
#endif
Ngram* bldLM(int order, const char* filename);
void deleteLM(Ngram* ngram);
float getSeqProb(Ngram* ngram, const char* ngramstr, unsigned
order, unsigned length);
#ifdef __cplusplus
}
#endif
MigMit:ngram MigMit$ cat srilm.c
#include "srilm.h"
Ngram* bldLM(int order, const char* filename) { return 0; }
void deleteLM(Ngram* ngram) {}
float getSeqProb(Ngram* ngram, const char* ngramstr, unsigned order,
unsigned length) { return 0;}
MigMit:ngram MigMit$
Maybe you just need to recompile srilm.c or something.
On 14 Jan 2010, at 23:39, DNM wrote:
Nope. Ubuntu Linux (Intrepid Ibex). I wish it were that simple.
--D.N.
Daniel Fischer-4 wrote:
Am Donnerstag 14 Januar 2010 20:42:42 schrieb DNM:
Which is weird, because 'srilm.o'/'srilm.h' are the files that
define
the mysterious "undefined references". I'll keep plugging away and
report back when (or whether) I make some progress. In the
meanwhile,
if anyone has a clue, I'm all ears.
Best,
D.N.
Just an idea. Are you on windows?
If so, then your foreign calls would probably have to be
foreign import stdcall "srilm.h whatever" ...
instead of
foreign import ccall "..."
Malcolm Wallace wrote:
However, if you are unsure of which Haskell packages are needed,
it is
wise to let ghc work out the dependencies for you, e.g. with
ghc --make Main.hs slirm.o
It cannot work out the C/C++ dependencies though, so every time you
get "undefined reference" linking errors, you must discover which C
code provides those symbols, and add its object file to the
commandline by hand.
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