+++ /dev/null
-%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
-%
-\section{Working with C strings}
-
-A collection of lower-level functions to help converting between
-C strings and Haskell Strings (packed or otherwise).
-
-A more user-friendly Haskell interface to packed string representation
-is the PackedString interface.
-
-\begin{code}
-module CString
- (
- unpackCString -- :: Addr -> [Char]
- , unpackNBytes -- :: Addr -> Int -> [Char]
- , unpackNBytesST -- :: Addr -> Int -> ST s [Char]
- , unpackNBytesAccST -- :: Addr -> Int -> [Char] -> ST s [Char]
- , unpackCString# -- :: Addr# -> [Char] **
- , unpackNBytes# -- :: Addr# -> Int# -> [Char] **
- , unpackNBytesST# -- :: Addr# -> Int# -> ST s [Char]
-
- -- terrrible names...
- , unpackCStringIO -- :: Addr -> IO String
- , unpackCStringLenIO -- :: Addr -> Int -> IO String
- , unpackNBytesIO -- :: Addr -> Int -> IO [Char]
- , unpackNBytesAccIO -- :: Addr -> Int -> [Char] -> IO [Char]
- , unpackNBytesBAIO -- :: ByteArray Int -> Int -> IO [Char]
- , unpackNBytesAccBAIO -- :: ByteArray Int -> Int -> [Char] -> IO [Char]
-
- , packString -- :: [Char] -> ByteArray Int
- , packStringST -- :: [Char] -> ST s (ByteArray Int)
- , packStringIO -- :: [Char] -> IO (ByteArray Int)
- , packNBytesST -- :: Int -> [Char] -> ByteArray Int
- , packCString# -- :: [Char] -> ByteArray#
-
- , unpackCStringBA -- :: ByteArray Int -> [Char]
- , unpackNBytesBA -- :: ByteArray Int -> Int -> [Char]
- , unpackCStringBA# -- :: ByteArray# -> Int# -> [Char]
- , unpackNBytesBA# -- :: ByteArray# -> Int# -> [Char]
-
- -- unmarshaling (char*) vectors.
- , unvectorize -- :: Addr -> Int -> IO [String]
- , vectorize -- :: [[Char]] -> IO (ByteArray Int)
-
-
- , allocChars -- :: Int -> IO (MutableByteArray RealWorld Int)
- , allocWords -- :: Int -> IO (MutableByteArray RealWorld Int)
- , freeze -- :: MutableByteArray RealWorld Int -> IO (ByteArray Int)
- , strcpy -- :: Addr -> IO String
-
- ) where
-
-import PrelPack
-import GlaExts
-import Addr
-import PrelIOBase ( IO(..) )
-import MutableArray
-
-\end{code}
-
-\begin{code}
-packStringIO :: [Char] -> IO (ByteArray Int)
-packStringIO str = stToIO (packStringST str)
-\end{code}
-
-\begin{code}
-unpackCStringIO :: Addr -> IO String
-unpackCStringIO addr
- | addr == nullAddr = return ""
- | otherwise = unpack 0#
- where
- unpack nh = do
- ch <- readCharOffAddr addr (I# nh)
- if ch == '\0'
- then return []
- else do
- ls <- unpack (nh +# 1#)
- return (ch : ls)
-
--- unpack 'len' chars
-unpackCStringLenIO :: Addr -> Int -> IO String
-unpackCStringLenIO addr l@(I# len#)
- | len# <# 0# = ioError (userError ("CString.unpackCStringLenIO: negative length (" ++ show l ++ ")"))
- | len# ==# 0# = return ""
- | otherwise = unpack [] (len# -# 1#)
- where
- unpack acc 0# = do
- ch <- readCharOffAddr addr (I# 0#)
- return (ch:acc)
- unpack acc nh = do
- ch <- readCharOffAddr addr (I# nh)
- unpack (ch:acc) (nh -# 1#)
-
-unpackNBytesIO :: Addr -> Int -> IO [Char]
-unpackNBytesIO a l = stToIO (unpackNBytesST a l)
-
-unpackNBytesAccIO :: Addr -> Int -> [Char] -> IO [Char]
-unpackNBytesAccIO a l acc = stToIO (unpackNBytesAccST a l acc)
-
-unpackNBytesBAIO :: ByteArray Int -> Int -> IO [Char]
-unpackNBytesBAIO ba l = unpackNBytesAccBAIO ba l []
-
--- note: no bounds checking!
-unpackNBytesAccBAIO :: ByteArray Int -> Int -> [Char] -> IO [Char]
-unpackNBytesAccBAIO _ 0 rest = return rest
-unpackNBytesAccBAIO (ByteArray _ _ ba) (I# len#) rest = unpack rest (len# -# 1#)
- where
- unpack acc i#
- | i# <# 0# = return acc
- | otherwise =
- case indexCharArray# ba i# of
- ch -> unpack (C# ch : acc) (i# -# 1#)
-
-\end{code}
-
-Turn a NULL-terminated vector of null-terminated strings into a string list
-(ToDo: create a module of common marshaling functions)
-
-\begin{code}
-unvectorize :: Addr -> Int -> IO [String]
-unvectorize ptr n
- | str == nullAddr = return []
- | otherwise = do
- x <- unpackCStringIO str
- xs <- unvectorize ptr (n+1)
- return (x : xs)
- where
- str = indexAddrOffAddr ptr n
-
-\end{code}
-
- Turn a string list into a NULL-terminated vector of null-terminated
-strings No indices...I hate indices. Death to Ix.
-
-\begin{code}
-vectorize :: [String] -> IO (ByteArray Int)
-vectorize vs = do
- arr <- allocWords (len + 1)
- fill arr 0 vs
- freeze arr
- where
- len :: Int
- len = length vs
-
- fill :: MutableByteArray RealWorld Int -> Int -> [String] -> IO ()
- fill arr n [] =
- _casm_ ``((PP_)%0)[%1] = NULL;'' arr n
- fill arr n (x:xs) = do
- barr <- packStringIO x
- _casm_ ``((PP_)%0)[%1] = (P_)%2;'' arr n barr
- fill arr (n+1) xs
-
-\end{code}
-
-Allocating chunks of memory in the Haskell heap, leaving
-out the bounds - use with care.
-
-\begin{code}
--- Allocate a mutable array of characters with no indices.
-allocChars :: Int -> IO (MutableByteArray RealWorld Int)
-allocChars size = stToIO (newCharArray (0,size))
-
-allocWords :: Int -> IO (MutableByteArray RealWorld Int)
-allocWords size = stToIO (newIntArray (0,size))
-
--- Freeze these index-free mutable arrays
-freeze :: MutableByteArray RealWorld Int -> IO (ByteArray Int)
-freeze mb = stToIO (unsafeFreezeByteArray mb)
-
--- Copy a null-terminated string from outside the heap to
--- Haskellized nonsense inside the heap
-strcpy :: Addr -> IO String
-strcpy str = unpackCStringIO str
-
-\end{code}
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