Data.Primitive.Ptr

Primitive operations on machine addresses

Since: 0.6.4.0

Types

data Ptr a

A value of type Ptr a represents a pointer to an object, or an array of objects, which may be marshalled to or from Haskell values of type a.

The type a will often be an instance of class Storable which provides the marshalling operations. However this is not essential, and you can provide your own operations to access the pointer. For example you might write small foreign functions to get or set the fields of a C struct.

Constructors

Ptr Addr#

Instances

NFData1 Ptr

Since: deepseq-1.4.3.0

Defined in Control.DeepSeq

Methods

liftRnf :: (a -> ()) -> Ptr a -> ()

Generic1 (URec (Ptr ()) :: k -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type Rep1 (URec (Ptr ())) :: k -> Type

Methods

from1 :: forall (a :: k0). URec (Ptr ()) a -> Rep1 (URec (Ptr ())) a

to1 :: forall (a :: k0). Rep1 (URec (Ptr ())) a -> URec (Ptr ()) a

Eq (Ptr a)

Since: base-2.1

Defined in GHC.Ptr

Methods

(==) :: Ptr a -> Ptr a -> Bool

(/=) :: Ptr a -> Ptr a -> Bool

Data a => Data (Ptr a)

Since: base-4.8.0.0

Defined in Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ptr a -> c (Ptr a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Ptr a)

toConstr :: Ptr a -> Constr

dataTypeOf :: Ptr a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Ptr a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Ptr a))

gmapT :: (forall b. Data b => b -> b) -> Ptr a -> Ptr a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ptr a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ptr a -> r

gmapQ :: (forall d. Data d => d -> u) -> Ptr a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Ptr a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ptr a -> m (Ptr a)

Ord (Ptr a)

Since: base-2.1

Defined in GHC.Ptr

Methods

compare :: Ptr a -> Ptr a -> Ordering

(<) :: Ptr a -> Ptr a -> Bool

(<=) :: Ptr a -> Ptr a -> Bool

(>) :: Ptr a -> Ptr a -> Bool

(>=) :: Ptr a -> Ptr a -> Bool

max :: Ptr a -> Ptr a -> Ptr a

min :: Ptr a -> Ptr a -> Ptr a

Show (Ptr a)

Since: base-2.1

Defined in GHC.Ptr

Methods

showsPrec :: Int -> Ptr a -> ShowS

show :: Ptr a -> String

showList :: [Ptr a] -> ShowS

Foldable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UAddr m -> m

foldMap :: Monoid m => (a -> m) -> UAddr a -> m

foldMap' :: Monoid m => (a -> m) -> UAddr a -> m

foldr :: (a -> b -> b) -> b -> UAddr a -> b

foldr' :: (a -> b -> b) -> b -> UAddr a -> b

foldl :: (b -> a -> b) -> b -> UAddr a -> b

foldl' :: (b -> a -> b) -> b -> UAddr a -> b

foldr1 :: (a -> a -> a) -> UAddr a -> a

foldl1 :: (a -> a -> a) -> UAddr a -> a

toList :: UAddr a -> [a]

null :: UAddr a -> Bool

length :: UAddr a -> Int

elem :: Eq a => a -> UAddr a -> Bool

maximum :: Ord a => UAddr a -> a

minimum :: Ord a => UAddr a -> a

sum :: Num a => UAddr a -> a

product :: Num a => UAddr a -> a

Traversable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UAddr a -> f (UAddr b)

sequenceA :: Applicative f => UAddr (f a) -> f (UAddr a)

mapM :: Monad m => (a -> m b) -> UAddr a -> m (UAddr b)

sequence :: Monad m => UAddr (m a) -> m (UAddr a)

Storable (Ptr a)

Since: base-2.1

Defined in Foreign.Storable

Methods

sizeOf :: Ptr a -> Int

alignment :: Ptr a -> Int

peekElemOff :: Ptr (Ptr a) -> Int -> IO (Ptr a)

pokeElemOff :: Ptr (Ptr a) -> Int -> Ptr a -> IO ()

peekByteOff :: Ptr b -> Int -> IO (Ptr a)

pokeByteOff :: Ptr b -> Int -> Ptr a -> IO ()

peek :: Ptr (Ptr a) -> IO (Ptr a)

poke :: Ptr (Ptr a) -> Ptr a -> IO ()

NFData (Ptr a)

Since: deepseq-1.4.2.0

Defined in Control.DeepSeq

Methods

rnf :: Ptr a -> ()

Prim (Ptr a)

Defined in Data.Primitive.Types

Methods

sizeOf# :: Ptr a -> Int#

alignment# :: Ptr a -> Int#

indexByteArray# :: ByteArray# -> Int# -> Ptr a

readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Ptr a #)

writeByteArray# :: MutableByteArray# s -> Int# -> Ptr a -> State# s -> State# s

setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Ptr a -> State# s -> State# s

indexOffAddr# :: Addr# -> Int# -> Ptr a

readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Ptr a #)

writeOffAddr# :: Addr# -> Int# -> Ptr a -> State# s -> State# s

setOffAddr# :: Addr# -> Int# -> Int# -> Ptr a -> State# s -> State# s

Functor (URec (Ptr ()) :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b

(<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a

Eq (URec (Ptr ()) p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(==) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

(/=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

Ord (URec (Ptr ()) p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering

(<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

(<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

(>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

(>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p

min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p

Generic (URec (Ptr ()) p)

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type Rep (URec (Ptr ()) p) :: Type -> Type

Methods

from :: URec (Ptr ()) p -> Rep (URec (Ptr ()) p) x

to :: Rep (URec (Ptr ()) p) x -> URec (Ptr ()) p

data URec (Ptr ()) (p :: k)

Used for marking occurrences of Addr#

Since: base-4.9.0.0

Defined in GHC.Generics

data URec (Ptr ()) (p :: k) = UAddr {

• uAddr# :: Addr#

}

type Rep1 (URec (Ptr ()) :: k -> Type)

Defined in GHC.Generics

type Rep1 (URec (Ptr ()) :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: k -> Type)))

type Rep (URec (Ptr ()) p)

Defined in GHC.Generics

type Rep (URec (Ptr ()) p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UAddr" 'PrefixI 'True) (S1 ('MetaSel ('Just "uAddr#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UAddr :: Type -> Type)))

Address arithmetic

nullPtr :: Ptr a

The constant nullPtr contains a distinguished value of Ptr that is not associated with a valid memory location.

advancePtr :: forall a. Prim a => Ptr a -> Int -> Ptr a

Offset a pointer by the given number of elements.

subtractPtr :: forall a. Prim a => Ptr a -> Ptr a -> Int

Subtract a pointer from another pointer. The result represents the number of elements of type a that fit in the contiguous memory range bounded by these two pointers.

Element access

indexOffPtr :: Prim a => Ptr a -> Int -> a

Read a value from a memory position given by a pointer and an offset. The memory block the address refers to must be immutable. The offset is in elements of type a rather than in bytes.

readOffPtr :: (Prim a, PrimMonad m) => Ptr a -> Int -> m a

Read a value from a memory position given by an address and an offset. The offset is in elements of type a rather than in bytes.

writeOffPtr :: (Prim a, PrimMonad m) => Ptr a -> Int -> a -> m ()

Write a value to a memory position given by an address and an offset. The offset is in elements of type a rather than in bytes.

Block operations

copyPtr

Arguments

:: forall m a. (PrimMonad m, Prim a)

=> Ptr a

destination pointer

-> Ptr a

source pointer

-> Int

number of elements

-> m ()

Copy the given number of elements from the second Ptr to the first. The areas may not overlap.

movePtr

Arguments

:: forall m a. (PrimMonad m, Prim a)

=> Ptr a

destination address

-> Ptr a

source address

-> Int

number of elements

-> m ()

Copy the given number of elements from the second Ptr to the first. The areas may overlap.

setPtr :: (Prim a, PrimMonad m) => Ptr a -> Int -> a -> m ()

Fill a memory block with the given value. The length is in elements of type a rather than in bytes.

copyPtrToMutablePrimArray

Arguments

:: forall m a. (PrimMonad m, Prim a)

=> MutablePrimArray (PrimState m) a

destination array

-> Int

destination offset

-> Ptr a

source pointer

-> Int

number of elements

-> m ()

Copy from a pointer to a mutable primitive array. The offset and length are given in elements of type a. This function is only available when building with GHC 7.8 or newer.

copyPtrToMutableByteArray

Arguments

:: forall m a. (PrimMonad m, Prim a)

=> MutableByteArray (PrimState m)

destination array

-> Int

destination offset given in elements of type a

-> Ptr a

source pointer

-> Int

number of elements

-> m ()

Copy from a pointer to a mutable byte array. The offset and length are given in elements of type a. This function is only available when building with GHC 7.8 or newer.