vector-0.7.0.1: Efficient ArraysContentsIndex
Data.Vector.Storable.Mutable
Portabilitynon-portable
Stabilityexperimental
MaintainerRoman Leshchinskiy <rl@cse.unsw.edu.au>
Contents
Mutable vectors of Storable types
Accessors
Length information
Extracting subvectors
Overlapping
Construction
Initialisation
Growing
Restricting memory usage
Accessing individual elements
Modifying vectors
Filling and copying
Raw pointers
Deprecated operations
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
null :: Storable a => MVector s a -> Bool
slice :: Storable a => Int -> Int -> MVector s a -> MVector s a
init :: Storable a => MVector s a -> MVector s a
tail :: Storable a => MVector s a -> MVector s a
take :: Storable a => Int -> MVector s a -> MVector s a
drop :: Storable a => Int -> MVector s a -> MVector s a
unsafeSlice :: Storable a => Int -> Int -> MVector s a -> MVector s a
unsafeInit :: Storable a => MVector s a -> MVector s a
unsafeTail :: Storable a => MVector s a -> MVector s a
unsafeTake :: Storable a => Int -> MVector s a -> MVector s a
unsafeDrop :: Storable a => Int -> MVector s a -> MVector s a
overlaps :: Storable a => MVector s a -> MVector s a -> Bool
new :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
unsafeNew :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
replicate :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
clone :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m (MVector (PrimState m) a)
grow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
unsafeGrow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
clear :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m ()
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 ()
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 ()
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 ()
unsafeCopy :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
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
newWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
unsafeNewWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
Mutable vectors of Storable types
data MVector s a
Mutable Storable-based vectors
Constructors
MVector !(Ptr a) !Int !(ForeignPtr a)
show/hide Instances
type IOVector = MVector RealWorld
type STVector s = MVector s
class Storable a

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.

show/hide Instances
Accessors
Length information
length :: Storable a => MVector s a -> Int
Length of the mutable vector.
null :: Storable a => MVector s a -> Bool
Check whether the vector is empty
Extracting subvectors
slice :: Storable a => Int -> Int -> MVector s a -> MVector s a
Yield a part of the mutable vector without copying it.
init :: Storable a => MVector s a -> MVector s a
tail :: Storable a => MVector s a -> MVector s a
take :: Storable a => Int -> MVector s a -> MVector s a
drop :: Storable a => Int -> MVector s a -> MVector s a
unsafeSlice
:: Storable a
=> Intstarting index
-> Intlength of the slice
-> MVector s a
-> MVector s a
Yield a part of the mutable vector without copying it. No bounds checks are performed.
unsafeInit :: Storable a => MVector s a -> MVector s a
unsafeTail :: Storable a => MVector s a -> MVector s a
unsafeTake :: Storable a => Int -> MVector s a -> MVector s a
unsafeDrop :: Storable a => Int -> MVector s a -> MVector s a
Overlapping
overlaps :: Storable a => MVector s a -> MVector s a -> Bool
Construction
Initialisation
new :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
Create a mutable vector of the given length.
unsafeNew :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a)
Create a mutable vector of the given length. The length is not checked.
replicate :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
Create a mutable vector of the given length (0 if the length is negative) and fill it with an initial value.
clone :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m (MVector (PrimState m) a)
Create a copy of a mutable vector.
Growing
grow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
Grow a vector by the given number of elements. The number must be positive.
unsafeGrow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)
Grow a vector by the given number of elements. The number must be positive but this is not checked.
Restricting memory usage
clear :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> m ()
Reset all elements of the vector to some undefined value, clearing all references to external objects. This is usually a noop for unboxed vectors.
Accessing individual elements
read :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a
Yield the element at the given position.
write :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()
Replace the element at the given position.
swap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
Swap the elements at the given positions.
unsafeRead :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a
Yield the element at the given position. No bounds checks are performed.
unsafeWrite :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> a -> m ()
Replace the element at the given position. No bounds checks are performed.
unsafeSwap :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> Int -> m ()
Swap the elements at the given positions. No bounds checks are performed.
Modifying vectors
Filling and copying
set :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> a -> m ()
Set all elements of the vector to the given value.
copy :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
Copy a vector. The two vectors must have the same length and may not overlap.
unsafeCopy
:: (PrimMonad m, Storable a)
=> MVector (PrimState m) atarget
-> MVector (PrimState m) asource
-> m ()
Copy a vector. The two vectors must have the same length and may not overlap. This is not checked.
Raw pointers
unsafeFromForeignPtr
:: Storable a
=> ForeignPtr apointer
-> Intoffset
-> Intlength
-> 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)
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 b
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.
Deprecated operations
newWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
DEPRECATED Use replicate instead
unsafeNewWith :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a)
DEPRECATED Use replicate instead
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