vector-0.6.0.1: Efficient ArraysSource codeContentsIndex
Data.Vector.Storable.Mutable
Portabilitynon-portable
Stabilityexperimental
MaintainerRoman Leshchinskiy <rl@cse.unsw.edu.au>
Contents
Mutable vectors of Storable types
Operations on mutable vectors
Unsafe operations
Accessing the underlying memory
Description
Mutable vectors based on Storable.
Synopsis
data MVector s a = MVector !(Ptr a) !Int !(ForeignPtr a)
type IOVector = MVector RealWorld
type STVector s = MVector s
class Storable a
length :: Storable a => MVector s a -> Int
overlaps :: Storable a => MVector s a -> MVector s a -> Bool
slice :: Storable a => Int -> Int -> MVector s a -> MVector s a
new :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
newWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
read :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a
write :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()
swap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
clear :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m ()
set :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> a -> m ()
copy :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
grow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
unsafeSlice :: Storable a => Int -> Int -> MVector s a -> MVector s a
unsafeNew :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
unsafeNewWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
unsafeRead :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a
unsafeWrite :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()
unsafeSwap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
unsafeCopy :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
unsafeGrow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
unsafeFromForeignPtr :: Storable a => ForeignPtr a -> Int -> Int -> MVector s a
unsafeToForeignPtr :: Storable a => MVector s a -> (ForeignPtr a, Int, Int)
unsafeWith :: Storable a => IOVector a -> (Ptr a -> IO b) -> IO b
Mutable vectors of Storable types
data MVector s a Source
Mutable Storable-based vectors
Constructors
MVector !(Ptr a) !Int !(ForeignPtr a)
type IOVector = MVector RealWorldSource
type STVector s = MVector sSource
class Storable a Source

The member functions of this class facilitate writing values of primitive types to raw memory (which may have been allocated with the above mentioned routines) and reading values from blocks of raw memory. The class, furthermore, includes support for computing the storage requirements and alignment restrictions of storable types.

Memory addresses are represented as values of type Ptr a, for some a which is an instance of class Storable. The type argument to Ptr helps provide some valuable type safety in FFI code (you can't mix pointers of different types without an explicit cast), while helping the Haskell type system figure out which marshalling method is needed for a given pointer.

All marshalling between Haskell and a foreign language ultimately boils down to translating Haskell data structures into the binary representation of a corresponding data structure of the foreign language and vice versa. To code this marshalling in Haskell, it is necessary to manipulate primitive data types stored in unstructured memory blocks. The class Storable facilitates this manipulation on all types for which it is instantiated, which are the standard basic types of Haskell, the fixed size Int types (Int8, Int16, Int32, Int64), the fixed size Word types (Word8, Word16, Word32, Word64), StablePtr, all types from Foreign.C.Types, as well as Ptr.

Minimal complete definition: sizeOf, alignment, one of peek, peekElemOff and peekByteOff, and one of poke, pokeElemOff and pokeByteOff.

Operations on mutable vectors
length :: Storable a => MVector s a -> IntSource
Length of the mutable vector.
overlaps :: Storable a => MVector s a -> MVector s a -> BoolSource
slice :: Storable a => Int -> Int -> MVector s a -> MVector s aSource
Yield a part of the mutable vector without copying it.
new :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)Source
Create a mutable vector of the given length.
newWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)Source
Create a mutable vector of the given length and fill it with an initial value.
read :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m aSource
Yield the element at the given position.
write :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()Source
Replace the element at the given position.
swap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()Source
Swap the elements at the given positions.
clear :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m ()Source
Reset all elements of the vector to some undefined value, clearing all references to external objects. This is usually a noop for unboxed vectors.
set :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> a -> m ()Source
Set all elements of the vector to the given value.
copy :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()Source
Copy a vector. The two vectors must have the same length and may not overlap.
grow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)Source
Grow a vector by the given number of elements. The number must be positive.
Unsafe operations
unsafeSliceSource
:: Storable a
=> Intlength of the slice
-> Int
-> MVector s a
-> MVector s a
Yield a part of the mutable vector without copying it. No bounds checks are performed.
unsafeNew :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)Source
Create a mutable vector of the given length. The length is not checked.
unsafeNewWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)Source
Create a mutable vector of the given length and fill it with an initial value. The length is not checked.
unsafeRead :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m aSource
Yield the element at the given position. No bounds checks are performed.
unsafeWrite :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()Source
Replace the element at the given position. No bounds checks are performed.
unsafeSwap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()Source
Swap the elements at the given positions. No bounds checks are performed.
unsafeCopySource
:: (PrimMonad m, Storable a)
=> MVector (PrimState m) asource
-> MVector (PrimState m) a
-> m ()
Copy a vector. The two vectors must have the same length and may not overlap. This is not checked.
unsafeGrow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)Source
Grow a vector by the given number of elements. The number must be positive but this is not checked.
Accessing the underlying memory
unsafeFromForeignPtrSource
:: Storable a
=> ForeignPtr aoffset
-> Intlength
-> Int
-> MVector s a
Create a mutable vector from a ForeignPtr with an offset and a length. Modifying data through the ForeignPtr afterwards is unsafe if the vector could have been frozen before the modification.
unsafeToForeignPtr :: Storable a => MVector s a -> (ForeignPtr a, Int, Int)Source
Yield the underlying ForeignPtr together with the offset to the data and its length. Modifying the data through the ForeignPtr is unsafe if the vector could have frozen before the modification.
unsafeWith :: Storable a => IOVector a -> (Ptr a -> IO b) -> IO bSource
Pass a pointer to the vector's data to the IO action. Modifying data through the pointer is unsafe if the vector could have been frozen before the modification.
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