vector-0.9.1: Efficient Arrays

Portability | non-portable
Stability | experimental
Maintainer | Roman Leshchinskiy <rl@cse.unsw.edu.au>
Safe Haskell | Safe-Infered

Data.Vector.Storable.Mutable

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
- Unsafe conversions
- Raw pointers

Description

Mutable vectors based on Storable.

Synopsis

- data MVector s a = MVector !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
- splitAt :: Storable a => Int -> MVector s a -> (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)
- replicateM :: (PrimMonad m, Storable a) => Int -> m 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 ()
- move :: (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 ()
- unsafeMove :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()
- unsafeCast :: forall a b s. (Storable a, Storable b) => MVector s a -> MVector s b
- unsafeFromForeignPtr :: Storable a => ForeignPtr a -> Int -> Int -> MVector s a
- unsafeFromForeignPtr0 :: Storable a => ForeignPtr a -> Int -> MVector s a
- unsafeToForeignPtr :: Storable a => MVector s a -> (ForeignPtr a, Int, Int)
- unsafeToForeignPtr0 :: Storable a => MVector s a -> (ForeignPtr a, Int)
- unsafeWith :: Storable a => IOVector a -> (Ptr a -> IO b) -> IO b

# Mutable vectors of `Storable` types

data MVector s a

Mutable `Storable`-based vectors

Constructors

MVector !Int !(ForeignPtr a) |

Instances

Typeable2 MVector |
Storable a => MVector MVector a |

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`.

Instances

Storable Bool |
Storable Char |
Storable Double |
Storable Float |
Storable Int |
Storable Int8 |
Storable Int16 |
Storable Int32 |
Storable Int64 |
Storable Word |
Storable Word8 |
Storable Word16 |
Storable Word32 |
Storable Word64 |
Storable WordPtr |
Storable IntPtr |
Storable CChar |
Storable CSChar |
Storable CUChar |
Storable CShort |
Storable CUShort |
Storable CInt |
Storable CUInt |
Storable CLong |
Storable CULong |
Storable CLLong |
Storable CULLong |
Storable CFloat |
Storable CDouble |
Storable CPtrdiff |
Storable CSize |
Storable CWchar |
Storable CSigAtomic |
Storable CClock |
Storable CTime |
Storable CUSeconds |
Storable CSUSeconds |
Storable CIntPtr |
Storable CUIntPtr |
Storable CIntMax |
Storable CUIntMax |
Storable Fingerprint |
Storable (StablePtr a) |
Storable (Ptr a) |
Storable (FunPtr a) |

# 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

splitAt :: Storable a => Int -> MVector s a -> (MVector s a, MVector s a)

unsafeSlice

Arguments

:: Storable a |
=> Int | starting index
-> Int | length 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.

replicateM :: (PrimMonad m, Storable a) => Int -> m a -> m (MVector (PrimState m) a)

Create a mutable vector of the given length (0 if the length is negative) and fill it with values produced by repeatedly executing the monadic action.

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.

move :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()

Move the contents of a vector. The two vectors must have the same length.

If the vectors do not overlap, then this is equivalent to `copy`. Otherwise, the copying is performed as if the source vector were copied to a temporary vector and then the temporary vector was copied to the target vector.

unsafeCopy

Arguments

:: (PrimMonad m, Storable a) |
=> MVector (PrimState m) a | target
-> MVector (PrimState m) a | source
-> m () |

Copy a vector. The two vectors must have the same length and may not overlap. This is not checked.

unsafeMove

Arguments

:: (PrimMonad m, Storable a) |
=> MVector (PrimState m) a | target
-> MVector (PrimState m) a | source
-> m () |

Move the contents of a vector. The two vectors must have the same length, but this is not checked.

If the vectors do not overlap, then this is equivalent to `unsafeCopy`. Otherwise, the copying is performed as if the source vector were copied to a temporary vector and then the temporary vector was copied to the target vector.

# Unsafe conversions

unsafeCast :: forall a b s. (Storable a, Storable b) => MVector s a -> MVector s b

O(1) Unsafely cast a mutable vector from one element type to another. The operation just changes the type of the underlying pointer and does not modify the elements.

The resulting vector contains as many elements as can fit into the underlying memory block.

# Raw pointers

unsafeFromForeignPtr

Arguments

:: Storable a |
=> ForeignPtr a | pointer
-> Int | offset
-> Int | length
-> 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.

If your offset is 0 it is more efficient to use `unsafeFromForeignPtr0`.

unsafeFromForeignPtr0

Arguments

:: Storable a |
=> ForeignPtr a | pointer
-> Int | length
-> MVector s a |

O(1) Create a mutable vector from a `ForeignPtr` and a length.

It is assumed the pointer points directly to the data (no offset). Use `unsafeFromForeignPtr` if you need to specify an offset.

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.

unsafeToForeignPtr0 :: Storable a => MVector s a -> (ForeignPtr a, Int)

O(1) Yield the underlying `ForeignPtr` together with its length.

You can assume the pointer points directly to the data (no offset).

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.