2 % (c) The AQUA Project, Glasgow University, 1994-1996
5 \section[Foreign]{Module @Foreign@}
8 {-# OPTIONS -fno-implicit-prelude #-}
12 #ifndef __PARALLEL_HASKELL__
28 %*********************************************************
30 \subsection{Type @ForeignObj@ and its operations}
32 %*********************************************************
35 #ifndef __PARALLEL_HASKELL__
36 --instance CCallable ForeignObj
37 --instance CCallable ForeignObj#
39 makeForeignObj :: Addr -> IO ForeignObj
40 makeForeignObj (A# obj) = IO ( \ s# ->
41 case makeForeignObj# obj s# of
42 (# s1#, fo# #) -> (# s1#, ForeignObj fo# #) )
44 eqForeignObj :: ForeignObj -> ForeignObj -> Bool
45 --makeForeignObj :: Addr -> Addr -> IO ForeignObj
46 writeForeignObj :: ForeignObj -> Addr -> IO ()
48 writeForeignObj (ForeignObj fo#) (A# datum#) = IO ( \ s# ->
49 case writeForeignObj# fo# datum# s# of { s1# -> (# s1#, () #) } )
52 = unsafePerformIO (_ccall_ eqForeignObj mp1 mp2) /= (0::Int)
54 instance Eq ForeignObj where
55 p == q = eqForeignObj p q
56 p /= q = not (eqForeignObj p q)
57 #endif /* !__PARALLEL_HASKELL__ */
60 %*********************************************************
62 \subsection{Unpacking Foreigns}
64 %*********************************************************
66 Primitives for converting Foreigns pointing to external
67 sequence of bytes into a list of @Char@s (a renamed version
71 #ifndef __PARALLEL_HASKELL__
72 unpackCStringFO :: ForeignObj -> [Char]
73 unpackCStringFO (ForeignObj fo#) = unpackCStringFO# fo#
75 unpackCStringFO# :: ForeignObj# -> [Char]
76 unpackCStringFO# fo {- ptr. to NUL terminated string-}
80 | ch `eqChar#` '\0'# = []
81 | otherwise = C# ch : unpack (nh +# 1#)
83 ch = indexCharOffForeignObj# fo nh
85 unpackNBytesFO :: ForeignObj -> Int -> [Char]
86 unpackNBytesFO (ForeignObj fo) (I# l) = unpackNBytesFO# fo l
88 unpackNBytesFO# :: ForeignObj# -> Int# -> [Char]
89 -- This one is called by the compiler to unpack literal strings with NULs in them; rare.
90 unpackNBytesFO# fo len
95 | otherwise = C# ch : unpack (i +# 1#)
97 ch = indexCharOffForeignObj# fo i