| 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
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 Int64
- 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 Int32
- newtype CTime = CTime Int64
- newtype CUSeconds = CUSeconds Word32
- newtype CSUSeconds = CSUSeconds Int64
- 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. sizeOf(undefined:: CT)sizeof (t)in C.alignment(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.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C signed char type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C unsigned char type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C short type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C unsigned short type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C int type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C unsigned int type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C long type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C unsigned long type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C ptrdiff_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C size_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C wchar_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
newtype CSigAtomic Source #
Haskell type representing the C sig_atomic_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
See Note [Lack of signals on wasm32-wasi].
Constructors
| CSigAtomic Int64 |
Instances
Haskell type representing the C long long type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C unsigned long long type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C bool type.
(The concrete types of Foreign.C.Types are platform-specific.)
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.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
| Storable CClock Source # | |
Defined in Foreign.C.Types Methods sizeOf :: CClock -> Int Source # alignment :: CClock -> Int Source # peekElemOff :: Ptr CClock -> Int -> IO CClock Source # pokeElemOff :: Ptr CClock -> Int -> CClock -> IO () Source # peekByteOff :: Ptr b -> Int -> IO CClock Source # pokeByteOff :: Ptr b -> Int -> CClock -> IO () Source # | |
| Enum CClock Source # | |
Defined in Foreign.C.Types Methods succ :: CClock -> CClock Source # pred :: CClock -> CClock Source # toEnum :: Int -> CClock Source # fromEnum :: CClock -> Int Source # enumFrom :: CClock -> [CClock] Source # enumFromThen :: CClock -> CClock -> [CClock] Source # enumFromTo :: CClock -> CClock -> [CClock] Source # enumFromThenTo :: CClock -> CClock -> CClock -> [CClock] Source # | |
| Num CClock Source # | |
Defined in Foreign.C.Types | |
| Read CClock Source # | |
| Real CClock Source # | |
Defined in Foreign.C.Types Methods toRational :: CClock -> Rational Source # | |
| Show CClock Source # | |
| Eq CClock Source # | |
| Ord CClock Source # | |
Haskell type representing the C time_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
| Storable CTime Source # | |
Defined in Foreign.C.Types Methods sizeOf :: CTime -> Int Source # alignment :: CTime -> Int Source # peekElemOff :: Ptr CTime -> Int -> IO CTime Source # pokeElemOff :: Ptr CTime -> Int -> CTime -> IO () Source # peekByteOff :: Ptr b -> Int -> IO CTime Source # pokeByteOff :: Ptr b -> Int -> CTime -> IO () Source # | |
| Enum CTime Source # | |
Defined in Foreign.C.Types Methods succ :: CTime -> CTime Source # pred :: CTime -> CTime Source # toEnum :: Int -> CTime Source # fromEnum :: CTime -> Int Source # enumFrom :: CTime -> [CTime] Source # enumFromThen :: CTime -> CTime -> [CTime] Source # enumFromTo :: CTime -> CTime -> [CTime] Source # enumFromThenTo :: CTime -> CTime -> CTime -> [CTime] Source # | |
| Num CTime Source # | |
| Read CTime Source # | |
| Real CTime Source # | |
Defined in Foreign.C.Types Methods toRational :: CTime -> Rational Source # | |
| Show CTime Source # | |
| Eq CTime Source # | |
| Ord CTime Source # | |
Defined in Foreign.C.Types | |
Haskell type representing the C useconds_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Since: base-4.4.0.0
Instances
newtype CSUSeconds Source #
Haskell type representing the C suseconds_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Since: base-4.4.0.0
Constructors
| CSUSeconds Int64 |
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.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Haskell type representing the C double type.
(The concrete types of Foreign.C.Types are platform-specific.)
Instances
Other types
Haskell type representing the C FILE type.
(The concrete types of Foreign.C.Types are platform-specific.)
Haskell type representing the C fpos_t type.
(The concrete types of Foreign.C.Types are platform-specific.)
Haskell type representing the C jmp_buf type.
(The concrete types of Foreign.C.Types are platform-specific.)