| Copyright | (c) Roman Leshchinskiy 2009-2010 |
|---|---|
| License | BSD-style |
| Maintainer | Roman Leshchinskiy <rl@cse.unsw.edu.au> |
| Stability | experimental |
| Portability | non-portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Vector.Storable.Mutable
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 ()
- modify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> 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 ()
- unsafeModify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> 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
Mutable Storable-based vectors
Constructors
| MVector !Int !(ForeignPtr a) |
Instances
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 aa 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, (peek | peekElemOff | peekByteOff), (poke | pokeElemOff | pokeByteOff)
Instances
Accessors
Length information
Extracting subvectors
Yield a part of the mutable vector without copying it. The vector must
contain at least i+n elements.
Yield a part of the mutable vector without copying it. No bounds checks are performed.
Overlapping
overlaps :: Storable a => MVector s a -> MVector s a -> Bool Source #
Check whether two vectors overlap.
Construction
Initialisation
new :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a) Source #
Create a mutable vector of the given length.
unsafeNew :: (PrimMonad m, Storable a) => Int -> m (MVector (PrimState m) a) Source #
Create a mutable vector of the given length. The vector content is uninitialized, which means it is filled with whatever underlying memory buffer happens to contain.
Since: 0.5
replicate :: (PrimMonad m, Storable a) => Int -> a -> m (MVector (PrimState m) a) Source #
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) Source #
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) Source #
Create a copy of a mutable vector.
Growing
grow :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a) Source #
Grow a storable vector by the given number of elements. The number must be
non-negative. Same semantics as in grow for generic vector.
Examples
>>>import qualified Data.Vector.Storable as VS>>>import qualified Data.Vector.Storable.Mutable as MVS>>>mv <- VS.thaw $ VS.fromList ([10, 20, 30] :: [Int])>>>mv' <- MVS.grow mv 2
Extra memory at the end of the newly allocated vector is initialized to 0
bytes, which for Storable instance will usually correspond to some default
value for a particular type, eg. 0 for Int, False for Bool,
etc. However, if unsafeGrow was used instead this would not have been
guaranteed and some garbage would be there instead:
>>>VS.unsafeFreeze mv'[10,20,30,0,0]
Having the extra space we can write new values in there:
>>>MVS.write mv' 3 999>>>VS.unsafeFreeze mv'[10,20,30,999,0]
It is important to note that the source mutable vector is not affected when the newly allocated one is mutated.
>>>MVS.write mv' 2 888>>>VS.unsafeFreeze mv'[10,20,888,999,0]>>>VS.unsafeFreeze mv[10,20,30]
Since: 0.5
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 non-negative but
this is not checked. Same semantics as in unsafeGrow for generic vector.
Since: 0.5
Restricting memory usage
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.
Accessing individual elements
read :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a Source #
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.
modify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> m () Source #
Modify 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.
unsafeRead :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> Int -> m a Source #
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.
unsafeModify :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> (a -> a) -> Int -> m () Source #
Modify 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.
Modifying vectors
Filling and copying
set :: (PrimMonad m, Storable a) => MVector (PrimState m) a -> a -> m () Source #
Set all elements of the vector to the given value.
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.
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.
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.
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.
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 Source #
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
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 Source #
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) 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.
unsafeToForeignPtr0 :: Storable a => MVector s a -> (ForeignPtr a, Int) Source #
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.