| Copyright | (c) The FFI task force 2001 |
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) |
| Maintainer | ffi@haskell.org |
| Stability | provisional |
| Portability | portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Foreign.C.Types
Contents
Description
Mapping of C types to corresponding Haskell types.
Synopsis
- newtype CChar = CChar Int8
- newtype CSChar = CSChar Int8
- newtype CUChar = CUChar Word8
- newtype CShort = CShort Int16
- newtype CUShort = CUShort Word16
- newtype CInt = CInt Int32
- newtype CUInt = CUInt Word32
- newtype CLong = CLong Int64
- newtype CULong = CULong Word64
- newtype CPtrdiff = CPtrdiff Int64
- newtype CSize = CSize Word64
- newtype CWchar = CWchar Int32
- newtype CSigAtomic = CSigAtomic Int32
- newtype CLLong = CLLong Int64
- newtype CULLong = CULLong Word64
- newtype CBool = CBool Word8
- newtype CIntPtr = CIntPtr Int64
- newtype CUIntPtr = CUIntPtr Word64
- newtype CIntMax = CIntMax Int64
- newtype CUIntMax = CUIntMax Word64
- newtype CClock = CClock Word64
- newtype CTime = CTime Int64
- newtype CUSeconds = CUSeconds Word32
- newtype CSUSeconds = CSUSeconds Int32
- newtype CFloat = CFloat Float
- newtype CDouble = CDouble Double
- data CFile
- data CFpos
- data CJmpBuf
Representations of C types
These types are needed to accurately represent C function prototypes,
in order to access C library interfaces in Haskell. The Haskell system
is not required to represent those types exactly as C does, but the
following guarantees are provided concerning a Haskell type CT
representing a C type t:
- If a C function prototype has
tas an argument or result type, the use ofCTin the corresponding position in a foreign declaration permits the Haskell program to access the full range of values encoded by the C type; and conversely, any Haskell value forCThas a valid representation in C. will yield the same value assizeOf(undefined:: CT)sizeof (t)in C.matches the alignment constraint enforced by the C implementation foralignment(undefined:: CT)t.- The members
peekandpokeof theStorableclass map all values ofCTto the corresponding value oftand vice versa. - When an instance of
Boundedis defined forCT, the values ofminBoundandmaxBoundcoincide witht_MINandt_MAXin C. - When an instance of
EqorOrdis defined forCT, the predicates defined by the type class implement the same relation as the corresponding predicate in C ont. - When an instance of
Num,Read,Integral,Fractional,Floating,RealFrac, orRealFloatis defined forCT, the arithmetic operations defined by the type class implement the same function as the corresponding arithmetic operations (if available) in C ont. - When an instance of
Bitsis defined forCT, the bitwise operation defined by the type class implement the same function as the corresponding bitwise operation in C ont.
Platform differences
This module contains platform specific information about types. __/As such the types presented on this page reflect the platform on which the documentation was generated and may not coincide with the types on your platform./__
Integral types
These types are represented as newtypes of
types in Data.Int and Data.Word, and are instances of
Eq, Ord, Num, Read,
Show, Enum, Typeable, Storable,
Bounded, Real, Integral and
Bits.
Haskell type representing the C char type.
Instances
Haskell type representing the C signed char type.
Instances
Haskell type representing the C unsigned char type.
Instances
Haskell type representing the C short type.
Instances
Haskell type representing the C unsigned short type.
Instances
Haskell type representing the C int type.
Instances
| Bounded CInt # | |
| Enum CInt # | |
| Eq CInt # | |
| Integral CInt # | |
| Num CInt # | |
| Ord CInt # | |
| Read CInt # | |
| Real CInt # | |
Defined in Foreign.C.Types Methods toRational :: CInt -> Rational # | |
| Show CInt # | |
| FiniteBits CInt # | |
Defined in Foreign.C.Types Methods finiteBitSize :: CInt -> Int # countLeadingZeros :: CInt -> Int # countTrailingZeros :: CInt -> Int # | |
| Bits CInt # | |
Defined in Foreign.C.Types Methods (.&.) :: CInt -> CInt -> CInt # (.|.) :: CInt -> CInt -> CInt # complement :: CInt -> CInt # shift :: CInt -> Int -> CInt # rotate :: CInt -> Int -> CInt # setBit :: CInt -> Int -> CInt # clearBit :: CInt -> Int -> CInt # complementBit :: CInt -> Int -> CInt # testBit :: CInt -> Int -> Bool # bitSizeMaybe :: CInt -> Maybe Int # shiftL :: CInt -> Int -> CInt # unsafeShiftL :: CInt -> Int -> CInt # shiftR :: CInt -> Int -> CInt # unsafeShiftR :: CInt -> Int -> CInt # rotateL :: CInt -> Int -> CInt # | |
| Storable CInt # | |
Defined in Foreign.C.Types | |
Haskell type representing the C unsigned int type.
Instances
Haskell type representing the C long type.
Instances
Haskell type representing the C unsigned long type.
Instances
Haskell type representing the C ptrdiff_t type.
Instances
Haskell type representing the C size_t type.
Instances
Haskell type representing the C wchar_t type.
Instances
newtype CSigAtomic #
Haskell type representing the C sig_atomic_t type.
Constructors
| CSigAtomic Int32 |
Instances
Haskell type representing the C long long type.
Instances
Haskell type representing the C unsigned long long type.
Instances
Haskell type representing the C bool type.
Since: base-4.10.0.0
Instances
Instances
Instances
Instances
Instances
Numeric types
These types are represented as newtypes of basic
foreign types, and are instances of
Eq, Ord, Num, Read,
Show, Enum, Typeable and Storable.
Haskell type representing the C clock_t type.
Instances
| Enum CClock # | |
Defined in Foreign.C.Types | |
| Eq CClock # | |
| Num CClock # | |
| Ord CClock # | |
| Read CClock # | |
| Real CClock # | |
Defined in Foreign.C.Types Methods toRational :: CClock -> Rational # | |
| Show CClock # | |
| Storable CClock # | |
Haskell type representing the C time_t type.
Instances
| Enum CTime # | |
Defined in Foreign.C.Types | |
| Eq CTime # | |
| Num CTime # | |
| Ord CTime # | |
Defined in Foreign.C.Types | |
| Read CTime # | |
| Real CTime # | |
Defined in Foreign.C.Types Methods toRational :: CTime -> Rational # | |
| Show CTime # | |
| Storable CTime # | |
Haskell type representing the C useconds_t type.
Since: base-4.4.0.0
Instances
| Enum CUSeconds # | |
Defined in Foreign.C.Types Methods succ :: CUSeconds -> CUSeconds # pred :: CUSeconds -> CUSeconds # fromEnum :: CUSeconds -> Int # enumFrom :: CUSeconds -> [CUSeconds] # enumFromThen :: CUSeconds -> CUSeconds -> [CUSeconds] # enumFromTo :: CUSeconds -> CUSeconds -> [CUSeconds] # enumFromThenTo :: CUSeconds -> CUSeconds -> CUSeconds -> [CUSeconds] # | |
| Eq CUSeconds # | |
| Num CUSeconds # | |
Defined in Foreign.C.Types | |
| Ord CUSeconds # | |
Defined in Foreign.C.Types | |
| Read CUSeconds # | |
| Real CUSeconds # | |
Defined in Foreign.C.Types Methods toRational :: CUSeconds -> Rational # | |
| Show CUSeconds # | |
| Storable CUSeconds # | |
Defined in Foreign.C.Types | |
newtype CSUSeconds #
Haskell type representing the C suseconds_t type.
Since: base-4.4.0.0
Constructors
| CSUSeconds Int32 |
Instances
To convert CTime to UTCTime, use the following:
\t -> posixSecondsToUTCTime (realToFrac t :: POSIXTime)
Floating types
These types are represented as newtypes of
Float and Double, and are instances of
Eq, Ord, Num, Read,
Show, Enum, Typeable, Storable,
Real, Fractional, Floating,
RealFrac and RealFloat. That does mean
that CFloat's (respectively CDouble's) instances of
Eq, Ord, Num and
Fractional are as badly behaved as Float's
(respectively Double's).
Haskell type representing the C float type.
Instances
| Enum CFloat # | |
Defined in Foreign.C.Types | |
| Eq CFloat # | |
| Floating CFloat # | |
| Fractional CFloat # | |
| Num CFloat # | |
| Ord CFloat # | |
| Read CFloat # | |
| Real CFloat # | |
Defined in Foreign.C.Types Methods toRational :: CFloat -> Rational # | |
| RealFloat CFloat # | |
Defined in Foreign.C.Types Methods floatRadix :: CFloat -> Integer # floatDigits :: CFloat -> Int # floatRange :: CFloat -> (Int, Int) # decodeFloat :: CFloat -> (Integer, Int) # encodeFloat :: Integer -> Int -> CFloat # significand :: CFloat -> CFloat # scaleFloat :: Int -> CFloat -> CFloat # isInfinite :: CFloat -> Bool # isDenormalized :: CFloat -> Bool # isNegativeZero :: CFloat -> Bool # | |
| RealFrac CFloat # | |
| Show CFloat # | |
| Storable CFloat # | |
Haskell type representing the C double type.
Instances
| Enum CDouble # | |
| Eq CDouble # | |
| Floating CDouble # | |
| Fractional CDouble # | |
| Num CDouble # | |
| Ord CDouble # | |
| Read CDouble # | |
| Real CDouble # | |
Defined in Foreign.C.Types Methods toRational :: CDouble -> Rational # | |
| RealFloat CDouble # | |
Defined in Foreign.C.Types Methods floatRadix :: CDouble -> Integer # floatDigits :: CDouble -> Int # floatRange :: CDouble -> (Int, Int) # decodeFloat :: CDouble -> (Integer, Int) # encodeFloat :: Integer -> Int -> CDouble # significand :: CDouble -> CDouble # scaleFloat :: Int -> CDouble -> CDouble # isInfinite :: CDouble -> Bool # isDenormalized :: CDouble -> Bool # isNegativeZero :: CDouble -> Bool # | |
| RealFrac CDouble # | |
| Show CDouble # | |
| Storable CDouble # | |