base-4.8.2.0: Basic libraries

Copyright(c) The FFI task force 2001
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerffi@haskell.org
Stabilityprovisional
Portabilityportable
Safe HaskellTrustworthy
LanguageHaskell2010

Foreign.C.Types

Contents

Description

Mapping of C types to corresponding Haskell types.

Synopsis

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 t as an argument or result type, the use of CT in 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 for CT has a valid representation in C.
  • sizeOf (undefined :: CT) will yield the same value as sizeof (t) in C.
  • alignment (undefined :: CT) matches the alignment constraint enforced by the C implementation for t.
  • The members peek and poke of the Storable class map all values of CT to the corresponding value of t and vice versa.
  • When an instance of Bounded is defined for CT, the values of minBound and maxBound coincide with t_MIN and t_MAX in C.
  • When an instance of Eq or Ord is defined for CT, the predicates defined by the type class implement the same relation as the corresponding predicate in C on t.
  • When an instance of Num, Read, Integral, Fractional, Floating, RealFrac, or RealFloat is defined for CT, the arithmetic operations defined by the type class implement the same function as the corresponding arithmetic operations (if available) in C on t.
  • When an instance of Bits is defined for CT, the bitwise operation defined by the type class implement the same function as the corresponding bitwise operation in C on t.

Integral types

These types are 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.

newtype CChar Source

Haskell type representing the C char type.

Constructors

CChar Int8 

Instances

Bounded CChar Source 
Enum CChar Source 
Eq CChar Source 

Methods

(==) :: CChar -> CChar -> Bool

(/=) :: CChar -> CChar -> Bool

Integral CChar Source 
Num CChar Source 
Ord CChar Source 

Methods

compare :: CChar -> CChar -> Ordering

(<) :: CChar -> CChar -> Bool

(<=) :: CChar -> CChar -> Bool

(>) :: CChar -> CChar -> Bool

(>=) :: CChar -> CChar -> Bool

max :: CChar -> CChar -> CChar

min :: CChar -> CChar -> CChar

Read CChar Source 
Real CChar Source 
Show CChar Source 
FiniteBits CChar Source 
Bits CChar Source 
Storable CChar Source 

newtype CSChar Source

Haskell type representing the C signed char type.

Constructors

CSChar Int8 

Instances

Bounded CSChar Source 
Enum CSChar Source 
Eq CSChar Source 

Methods

(==) :: CSChar -> CSChar -> Bool

(/=) :: CSChar -> CSChar -> Bool

Integral CSChar Source 
Num CSChar Source 
Ord CSChar Source 
Read CSChar Source 
Real CSChar Source 
Show CSChar Source 
FiniteBits CSChar Source 
Bits CSChar Source 
Storable CSChar Source 

newtype CUChar Source

Haskell type representing the C unsigned char type.

Constructors

CUChar Word8 

Instances

Bounded CUChar Source 
Enum CUChar Source 
Eq CUChar Source 

Methods

(==) :: CUChar -> CUChar -> Bool

(/=) :: CUChar -> CUChar -> Bool

Integral CUChar Source 
Num CUChar Source 
Ord CUChar Source 
Read CUChar Source 
Real CUChar Source 
Show CUChar Source 
FiniteBits CUChar Source 
Bits CUChar Source 
Storable CUChar Source 

newtype CShort Source

Haskell type representing the C short type.

Constructors

CShort Int16 

Instances

Bounded CShort Source 
Enum CShort Source 
Eq CShort Source 

Methods

(==) :: CShort -> CShort -> Bool

(/=) :: CShort -> CShort -> Bool

Integral CShort Source 
Num CShort Source 
Ord CShort Source 
Read CShort Source 
Real CShort Source 
Show CShort Source 
FiniteBits CShort Source 
Bits CShort Source 
Storable CShort Source 

newtype CUShort Source

Haskell type representing the C unsigned short type.

Constructors

CUShort Word16 

Instances

Bounded CUShort Source 
Enum CUShort Source 
Eq CUShort Source 

Methods

(==) :: CUShort -> CUShort -> Bool

(/=) :: CUShort -> CUShort -> Bool

Integral CUShort Source 
Num CUShort Source 
Ord CUShort Source 
Read CUShort Source 
Real CUShort Source 
Show CUShort Source 
FiniteBits CUShort Source 
Bits CUShort Source 
Storable CUShort Source 

newtype CInt Source

Haskell type representing the C int type.

Constructors

CInt Int32 

Instances

Bounded CInt Source 
Enum CInt Source 
Eq CInt Source 

Methods

(==) :: CInt -> CInt -> Bool

(/=) :: CInt -> CInt -> Bool

Integral CInt Source 
Num CInt Source 
Ord CInt Source 

Methods

compare :: CInt -> CInt -> Ordering

(<) :: CInt -> CInt -> Bool

(<=) :: CInt -> CInt -> Bool

(>) :: CInt -> CInt -> Bool

(>=) :: CInt -> CInt -> Bool

max :: CInt -> CInt -> CInt

min :: CInt -> CInt -> CInt

Read CInt Source 
Real CInt Source 
Show CInt Source 
FiniteBits CInt Source 
Bits CInt Source 
Storable CInt Source 

newtype CUInt Source

Haskell type representing the C unsigned int type.

Constructors

CUInt Word32 

Instances

Bounded CUInt Source 
Enum CUInt Source 
Eq CUInt Source 

Methods

(==) :: CUInt -> CUInt -> Bool

(/=) :: CUInt -> CUInt -> Bool

Integral CUInt Source 
Num CUInt Source 
Ord CUInt Source 

Methods

compare :: CUInt -> CUInt -> Ordering

(<) :: CUInt -> CUInt -> Bool

(<=) :: CUInt -> CUInt -> Bool

(>) :: CUInt -> CUInt -> Bool

(>=) :: CUInt -> CUInt -> Bool

max :: CUInt -> CUInt -> CUInt

min :: CUInt -> CUInt -> CUInt

Read CUInt Source 
Real CUInt Source 
Show CUInt Source 
FiniteBits CUInt Source 
Bits CUInt Source 
Storable CUInt Source 

newtype CLong Source

Haskell type representing the C long type.

Constructors

CLong Int64 

Instances

Bounded CLong Source 
Enum CLong Source 
Eq CLong Source 

Methods

(==) :: CLong -> CLong -> Bool

(/=) :: CLong -> CLong -> Bool

Integral CLong Source 
Num CLong Source 
Ord CLong Source 

Methods

compare :: CLong -> CLong -> Ordering

(<) :: CLong -> CLong -> Bool

(<=) :: CLong -> CLong -> Bool

(>) :: CLong -> CLong -> Bool

(>=) :: CLong -> CLong -> Bool

max :: CLong -> CLong -> CLong

min :: CLong -> CLong -> CLong

Read CLong Source 
Real CLong Source 
Show CLong Source 
FiniteBits CLong Source 
Bits CLong Source 
Storable CLong Source 

newtype CULong Source

Haskell type representing the C unsigned long type.

Constructors

CULong Word64 

Instances

Bounded CULong Source 
Enum CULong Source 
Eq CULong Source 

Methods

(==) :: CULong -> CULong -> Bool

(/=) :: CULong -> CULong -> Bool

Integral CULong Source 
Num CULong Source 
Ord CULong Source 
Read CULong Source 
Real CULong Source 
Show CULong Source 
FiniteBits CULong Source 
Bits CULong Source 
Storable CULong Source 

newtype CPtrdiff Source

Haskell type representing the C ptrdiff_t type.

Constructors

CPtrdiff Int64 

Instances

Bounded CPtrdiff Source 
Enum CPtrdiff Source 
Eq CPtrdiff Source 
Integral CPtrdiff Source 
Num CPtrdiff Source 
Ord CPtrdiff Source 
Read CPtrdiff Source 
Real CPtrdiff Source 
Show CPtrdiff Source 
FiniteBits CPtrdiff Source 
Bits CPtrdiff Source 
Storable CPtrdiff Source 

newtype CSize Source

Haskell type representing the C size_t type.

Constructors

CSize Word64 

Instances

Bounded CSize Source 
Enum CSize Source 
Eq CSize Source 

Methods

(==) :: CSize -> CSize -> Bool

(/=) :: CSize -> CSize -> Bool

Integral CSize Source 
Num CSize Source 
Ord CSize Source 

Methods

compare :: CSize -> CSize -> Ordering

(<) :: CSize -> CSize -> Bool

(<=) :: CSize -> CSize -> Bool

(>) :: CSize -> CSize -> Bool

(>=) :: CSize -> CSize -> Bool

max :: CSize -> CSize -> CSize

min :: CSize -> CSize -> CSize

Read CSize Source 
Real CSize Source 
Show CSize Source 
FiniteBits CSize Source 
Bits CSize Source 
Storable CSize Source 

newtype CWchar Source

Haskell type representing the C wchar_t type.

Constructors

CWchar Int32 

Instances

Bounded CWchar Source 
Enum CWchar Source 
Eq CWchar Source 

Methods

(==) :: CWchar -> CWchar -> Bool

(/=) :: CWchar -> CWchar -> Bool

Integral CWchar Source 
Num CWchar Source 
Ord CWchar Source 
Read CWchar Source 
Real CWchar Source 
Show CWchar Source 
FiniteBits CWchar Source 
Bits CWchar Source 
Storable CWchar Source 

newtype CSigAtomic Source

Haskell type representing the C sig_atomic_t type.

Constructors

CSigAtomic Int32 

Instances

Bounded CSigAtomic Source 
Enum CSigAtomic Source 
Eq CSigAtomic Source 
Integral CSigAtomic Source 
Num CSigAtomic Source 
Ord CSigAtomic Source 
Read CSigAtomic Source 
Real CSigAtomic Source 
Show CSigAtomic Source 
FiniteBits CSigAtomic Source 
Bits CSigAtomic Source 
Storable CSigAtomic Source 

newtype CLLong Source

Haskell type representing the C long long type.

Constructors

CLLong Int64 

Instances

Bounded CLLong Source 
Enum CLLong Source 
Eq CLLong Source 

Methods

(==) :: CLLong -> CLLong -> Bool

(/=) :: CLLong -> CLLong -> Bool

Integral CLLong Source 
Num CLLong Source 
Ord CLLong Source 
Read CLLong Source 
Real CLLong Source 
Show CLLong Source 
FiniteBits CLLong Source 
Bits CLLong Source 
Storable CLLong Source 

newtype CULLong Source

Haskell type representing the C unsigned long long type.

Constructors

CULLong Word64 

Instances

Bounded CULLong Source 
Enum CULLong Source 
Eq CULLong Source 

Methods

(==) :: CULLong -> CULLong -> Bool

(/=) :: CULLong -> CULLong -> Bool

Integral CULLong Source 
Num CULLong Source 
Ord CULLong Source 
Read CULLong Source 
Real CULLong Source 
Show CULLong Source 
FiniteBits CULLong Source 
Bits CULLong Source 
Storable CULLong Source 

newtype CIntPtr Source

Constructors

CIntPtr Int64 

Instances

Bounded CIntPtr Source 
Enum CIntPtr Source 
Eq CIntPtr Source 

Methods

(==) :: CIntPtr -> CIntPtr -> Bool

(/=) :: CIntPtr -> CIntPtr -> Bool

Integral CIntPtr Source 
Num CIntPtr Source 
Ord CIntPtr Source 
Read CIntPtr Source 
Real CIntPtr Source 
Show CIntPtr Source 
FiniteBits CIntPtr Source 
Bits CIntPtr Source 
Storable CIntPtr Source 

newtype CUIntPtr Source

Constructors

CUIntPtr Word64 

Instances

Bounded CUIntPtr Source 
Enum CUIntPtr Source 
Eq CUIntPtr Source 
Integral CUIntPtr Source 
Num CUIntPtr Source 
Ord CUIntPtr Source 
Read CUIntPtr Source 
Real CUIntPtr Source 
Show CUIntPtr Source 
FiniteBits CUIntPtr Source 
Bits CUIntPtr Source 
Storable CUIntPtr Source 

newtype CIntMax Source

Constructors

CIntMax Int64 

Instances

Bounded CIntMax Source 
Enum CIntMax Source 
Eq CIntMax Source 

Methods

(==) :: CIntMax -> CIntMax -> Bool

(/=) :: CIntMax -> CIntMax -> Bool

Integral CIntMax Source 
Num CIntMax Source 
Ord CIntMax Source 
Read CIntMax Source 
Real CIntMax Source 
Show CIntMax Source 
FiniteBits CIntMax Source 
Bits CIntMax Source 
Storable CIntMax Source 

newtype CUIntMax Source

Constructors

CUIntMax Word64 

Instances

Bounded CUIntMax Source 
Enum CUIntMax Source 
Eq CUIntMax Source 
Integral CUIntMax Source 
Num CUIntMax Source 
Ord CUIntMax Source 
Read CUIntMax Source 
Real CUIntMax Source 
Show CUIntMax Source 
FiniteBits CUIntMax Source 
Bits CUIntMax Source 
Storable CUIntMax Source 

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.

newtype CClock Source

Haskell type representing the C clock_t type.

Constructors

CClock Int64 

Instances

Enum CClock Source 
Eq CClock Source 

Methods

(==) :: CClock -> CClock -> Bool

(/=) :: CClock -> CClock -> Bool

Num CClock Source 
Ord CClock Source 
Read CClock Source 
Real CClock Source 
Show CClock Source 
Storable CClock Source 

newtype CTime Source

Haskell type representing the C time_t type.

Constructors

CTime Int64 

Instances

Enum CTime Source 
Eq CTime Source 

Methods

(==) :: CTime -> CTime -> Bool

(/=) :: CTime -> CTime -> Bool

Num CTime Source 
Ord CTime Source 

Methods

compare :: CTime -> CTime -> Ordering

(<) :: CTime -> CTime -> Bool

(<=) :: CTime -> CTime -> Bool

(>) :: CTime -> CTime -> Bool

(>=) :: CTime -> CTime -> Bool

max :: CTime -> CTime -> CTime

min :: CTime -> CTime -> CTime

Read CTime Source 
Real CTime Source 
Show CTime Source 
Storable CTime Source 

newtype CUSeconds Source

Haskell type representing the C useconds_t type.

Since: 4.4.0.0

Constructors

CUSeconds Word32 

Instances

Enum CUSeconds Source 
Eq CUSeconds Source 
Num CUSeconds Source 
Ord CUSeconds Source 
Read CUSeconds Source 
Real CUSeconds Source 
Show CUSeconds Source 
Storable CUSeconds Source 

newtype CSUSeconds Source

Haskell type representing the C suseconds_t type.

Since: 4.4.0.0

Constructors

CSUSeconds Int64 

Instances

Enum CSUSeconds Source 
Eq CSUSeconds Source 
Num CSUSeconds Source 
Ord CSUSeconds Source 
Read CSUSeconds Source 
Real CSUSeconds Source 
Show CSUSeconds Source 
Storable CSUSeconds Source 

To convert CTime to UTCTime, use the following:

\t -> posixSecondsToUTCTime (realToFrac t :: POSIXTime)

Floating types

These types are 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.

newtype CFloat Source

Haskell type representing the C float type.

Constructors

CFloat Float 

Instances

Enum CFloat Source 
Eq CFloat Source 

Methods

(==) :: CFloat -> CFloat -> Bool

(/=) :: CFloat -> CFloat -> Bool

Floating CFloat Source 
Fractional CFloat Source 
Num CFloat Source 
Ord CFloat Source 
Read CFloat Source 
Real CFloat Source 
RealFloat CFloat Source 
RealFrac CFloat Source 
Show CFloat Source 
Storable CFloat Source 

newtype CDouble Source

Haskell type representing the C double type.

Constructors

CDouble Double 

Instances

Enum CDouble Source 
Eq CDouble Source 

Methods

(==) :: CDouble -> CDouble -> Bool

(/=) :: CDouble -> CDouble -> Bool

Floating CDouble Source 
Fractional CDouble Source 
Num CDouble Source 
Ord CDouble Source 
Read CDouble Source 
Real CDouble Source 
RealFloat CDouble Source 
RealFrac CDouble Source 
Show CDouble Source 
Storable CDouble Source 

Other types

data CFile Source

Haskell type representing the C FILE type.

data CFpos Source

Haskell type representing the C fpos_t type.

data CJmpBuf Source

Haskell type representing the C jmp_buf type.