Safe Haskell | Safe |
---|---|
Language | Haskell2010 |
- data CChar :: *
- data CSChar :: *
- data CUChar :: *
- data CShort :: *
- data CUShort :: *
- data CInt :: *
- data CUInt :: *
- data CLong :: *
- data CULong :: *
- data CPtrdiff :: *
- data CSize :: *
- data CWchar :: *
- data CSigAtomic :: *
- data CLLong :: *
- data CULLong :: *
- data CIntPtr :: *
- data CUIntPtr :: *
- data CIntMax :: *
- data CUIntMax :: *
- data CClock :: *
- data CTime :: *
- data CFloat :: *
- data CDouble :: *
- 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
t
as an argument or result type, the use ofCT
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 forCT
has 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
peek
andpoke
of theStorable
class map all values ofCT
to the corresponding value oft
and vice versa. - When an instance of
Bounded
is defined forCT
, the values ofminBound
andmaxBound
coincide witht_MIN
andt_MAX
in C. - When an instance of
Eq
orOrd
is 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
, orRealFloat
is 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
Bits
is defined forCT
, the bitwise operation defined by the type class implement the same function as the corresponding bitwise operation in C ont
.
Integral types
These types are are represented as newtype
s of
types in Data.Int and Data.Word, and are instances of
Eq
, Ord
, Num
, Read
,
Show
, Enum
, Storable
,
Bounded
, Real
, Integral
and
Bits
.
Haskell type representing the C char
type.
Haskell type representing the C signed char
type.
Haskell type representing the C unsigned char
type.
Haskell type representing the C short
type.
Haskell type representing the C unsigned short
type.
Haskell type representing the C int
type.
Haskell type representing the C unsigned int
type.
Haskell type representing the C long
type.
Haskell type representing the C unsigned long
type.
Haskell type representing the C ptrdiff_t
type.
Haskell type representing the C size_t
type.
Haskell type representing the C wchar_t
type.
data CSigAtomic :: * Source
Haskell type representing the C sig_atomic_t
type.
Haskell type representing the C long long
type.
Haskell type representing the C unsigned long long
type.
Numeric types
These types are are represented as newtype
s of basic
foreign types, and are instances of
Eq
, Ord
, Num
, Read
,
Show
, Enum
and Storable
.
Haskell type representing the C clock_t
type.
Haskell type representing the C time_t
type.
Floating types
These types are are represented as newtype
s of
Float
and Double
, and are instances of
Eq
, Ord
, Num
, Read
,
Show
, Enum
, Storable
,
Real
, Fractional
, Floating
,
RealFrac
and RealFloat
.
Haskell type representing the C float
type.
Haskell type representing the C double
type.