This library provides machine addresses, i.e., handles to chunks of raw memory. It is primarily intended for use with the Foreign Function Interface (FFI) and will usually be imported via the module Foreign (see Section 4.9).
data Addr -- abstract handle for memory addresses
-- instance of: Eq, Ord, Show, Typeable
data AddrOff -- abstract handle of address offsets
-- instance of: Eq, Ord, Show, Enum, Num, Real, Integral, Typeable
nullAddr :: Addr
alignAddr :: Addr -> Int -> Addr
plusAddr :: Addr -> AddrOff -> Addr
minusAddr :: Addr -> Addr -> AddrOff |
The following specifies the behaviour of the four function definitions.
The constant nullAddr contains a distinguished value of Addr that denotes the absence of an address that is associated with a valid memory location.
Given an arbitrary address and an alignment constraint, alignAddr yields the next higher address that fulfills the alignment constraint. An alignment constraint x is fulfilled by any address divisible by x. This operation is idempotent.
Advances the given address by the given address offset.
Computes the offset required to get from the first to the second argument. We have
a2 == a1 `plusAddr` (a2 `minusAddr` a1) |
The following definition is available to C programs inter-operating with Haskell code when including the header HsFFI.h.
typedef void* HsAddr; /* C representation of an Addr */ |
The following functions are deprecated in the new FFI. Use the module Storable (Section 4.25) instead.
-- read value out of _immutable_ memory indexCharOffAddr :: Addr -> Int -> Char indexIntOffAddr :: Addr -> Int -> Int indexAddrOffAddr :: Addr -> Int -> Addr indexFloatOffAddr :: Addr -> Int -> Float indexDoubleOffAddr :: Addr -> Int -> Double indexWord8OffAddr :: Addr -> Int -> Word8 indexWord16OffAddr :: Addr -> Int -> Word16 indexWord32OffAddr :: Addr -> Int -> Word32 indexWord64OffAddr :: Addr -> Int -> Word64 indexInt8OffAddr :: Addr -> Int -> Int8 indexInt16OffAddr :: Addr -> Int -> Int16 indexInt32OffAddr :: Addr -> Int -> Int32 indexInt64OffAddr :: Addr -> Int -> Int64 indexStablePtrOffAddr :: Addr -> Int -> StablePtr a -- read value out of mutable memory readCharOffAddr :: Addr -> Int -> IO Char readIntOffAddr :: Addr -> Int -> IO Int readAddrOffAddr :: Addr -> Int -> IO Addr readFloatOffAddr :: Addr -> Int -> IO Float readDoubleOffAddr :: Addr -> Int -> IO Double readWord8OffAddr :: Addr -> Int -> IO Word8 readWord16OffAddr :: Addr -> Int -> IO Word16 readWord32OffAddr :: Addr -> Int -> IO Word32 readWord64OffAddr :: Addr -> Int -> IO Word64 readInt8OffAddr :: Addr -> Int -> IO Int8 readInt16OffAddr :: Addr -> Int -> IO Int16 readInt32OffAddr :: Addr -> Int -> IO Int32 readInt64OffAddr :: Addr -> Int -> IO Int64 readStablePtrOffAddr :: Addr -> Int -> IO (StablePtr a) -- write value into mutable memory writeCharOffAddr :: Addr -> Int -> Char -> IO () writeIntOffAddr :: Addr -> Int -> Int -> IO () writeAddrOffAddr :: Addr -> Int -> Addr -> IO () writeFloatOffAddr :: Addr -> Int -> Float -> IO () writeDoubleOffAddr :: Addr -> Int -> Double -> IO () writeWord8OffAddr :: Addr -> Int -> Word8 -> IO () writeWord16OffAddr :: Addr -> Int -> Word16 -> IO () writeWord32OffAddr :: Addr -> Int -> Word32 -> IO () writeWord64OffAddr :: Addr -> Int -> Word64 -> IO () writeInt8OffAddr :: Addr -> Int -> Int8 -> IO () writeInt16OffAddr :: Addr -> Int -> Int16 -> IO () writeInt32OffAddr :: Addr -> Int -> Int32 -> IO () writeInt64OffAddr :: Addr -> Int -> Int64 -> IO () writeForeignObjOffAddr :: Addr -> Int -> ForeignObj -> IO () writeStablePtrOffAddr :: Addr -> Int -> StablePtr a -> IO () -- conversion to/from Int, a little bit doubtful... addrToInt :: Addr -> Int intToAddr :: Int -> Addr -- completely deprecated data Word = W# Word# wordToInt :: Word -> Int intToWord :: Int -> Word |
Hugs provides Addr and nullAddr but does not provide any of the index, read or write functions. They can be implemented using GreenCard if required.