haskell2010-1.1.1.1: Compatibility with Haskell 2010

Safe HaskellSafe
LanguageHaskell2010

Foreign.C.Types

Contents

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, Storable, Bounded, Real, Integral and Bits.

data CChar :: *

Haskell type representing the C char type.

Instances

data CSChar :: *

Haskell type representing the C signed char type.

Instances

data CUChar :: *

Haskell type representing the C unsigned char type.

Instances

data CShort :: *

Haskell type representing the C short type.

Instances

data CUShort :: *

Haskell type representing the C unsigned short type.

Instances

data CInt :: *

Haskell type representing the C int type.

Instances

data CUInt :: *

Haskell type representing the C unsigned int type.

Instances

data CLong :: *

Haskell type representing the C long type.

Instances

data CULong :: *

Haskell type representing the C unsigned long type.

Instances

data CPtrdiff :: *

Haskell type representing the C ptrdiff_t type.

Instances

data CSize :: *

Haskell type representing the C size_t type.

Instances

data CWchar :: *

Haskell type representing the C wchar_t type.

Instances

data CSigAtomic :: *

Haskell type representing the C sig_atomic_t type.

Instances

data CLLong :: *

Haskell type representing the C long long type.

Instances

data CULLong :: *

Haskell type representing the C unsigned long long type.

Instances

data CIntPtr :: *

Instances

data CUIntPtr :: *

Instances

data CIntMax :: *

Instances

data CUIntMax :: *

Instances

Numeric types

These types are are represented as newtypes of basic foreign types, and are instances of Eq, Ord, Num, Read, Show, Enum and Storable.

data CClock :: *

Haskell type representing the C clock_t type.

Instances

data CTime :: *

Haskell type representing the C time_t type.

Instances

Floating types

These types are are represented as newtypes of Float and Double, and are instances of Eq, Ord, Num, Read, Show, Enum, Storable, Real, Fractional, Floating, RealFrac and RealFloat.

data CFloat :: *

Haskell type representing the C float type.

Instances

data CDouble :: *

Haskell type representing the C double type.

Instances

Other types

data CFile :: *

Haskell type representing the C FILE type.

data CFpos :: *

Haskell type representing the C fpos_t type.

data CJmpBuf :: *

Haskell type representing the C jmp_buf type.