| Copyright | (c) The University of Glasgow 2001 |
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) |
| Maintainer | libraries@haskell.org |
| Stability | experimental |
| Portability | non-portable (uses Data.Array.Base) |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Array.MArray
Contents
Description
An overloaded interface to mutable arrays. For array types which can be used with this interface, see Data.Array.IO, Data.Array.ST, and Data.Array.Storable.
- class Monad m => MArray a e m where
- module Data.Ix
- newListArray :: (MArray a e m, Ix i) => (i, i) -> [e] -> m (a i e)
- readArray :: (MArray a e m, Ix i) => a i e -> i -> m e
- writeArray :: (MArray a e m, Ix i) => a i e -> i -> e -> m ()
- mapArray :: (MArray a e' m, MArray a e m, Ix i) => (e' -> e) -> a i e' -> m (a i e)
- mapIndices :: (MArray a e m, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> m (a i e)
- getElems :: (MArray a e m, Ix i) => a i e -> m [e]
- getAssocs :: (MArray a e m, Ix i) => a i e -> m [(i, e)]
- freeze :: (Ix i, MArray a e m, IArray b e) => a i e -> m (b i e)
- thaw :: (Ix i, IArray a e, MArray b e m) => a i e -> m (b i e)
Class of mutable array types
class Monad m => MArray a e m where Source
Class of mutable array types.
An array type has the form (a i e) where a is the array type
constructor (kind * -> * -> *), i is the index type (a member of
the class Ix), and e is the element type.
The MArray class is parameterised over both a and e (so that
instances specialised to certain element types can be defined, in the
same way as for IArray), and also over the type of the monad, m,
in which the mutable array will be manipulated.
Minimal complete definition
getBounds, getNumElements, unsafeRead, unsafeWrite
Methods
getBounds :: Ix i => a i e -> m (i, i) Source
Returns the bounds of the array
newArray :: Ix i => (i, i) -> e -> m (a i e) Source
Builds a new array, with every element initialised to the supplied value.
newArray_ :: Ix i => (i, i) -> m (a i e) Source
Builds a new array, with every element initialised to an undefined value. In a monadic context in which operations must be deterministic (e.g. the ST monad), the array elements are initialised to a fixed but undefined value, such as zero.
Instances
The Ix class and operations
module Data.Ix
Constructing mutable arrays
newListArray :: (MArray a e m, Ix i) => (i, i) -> [e] -> m (a i e) Source
Constructs a mutable array from a list of initial elements. The list gives the elements of the array in ascending order beginning with the lowest index.
Reading and writing mutable arrays
writeArray :: (MArray a e m, Ix i) => a i e -> i -> e -> m () Source
Write an element in a mutable array
Derived arrays
mapArray :: (MArray a e' m, MArray a e m, Ix i) => (e' -> e) -> a i e' -> m (a i e) Source
Constructs a new array derived from the original array by applying a function to each of the elements.
mapIndices :: (MArray a e m, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> m (a i e) Source
Constructs a new array derived from the original array by applying a function to each of the indices.
Deconstructing mutable arrays
getElems :: (MArray a e m, Ix i) => a i e -> m [e] Source
Return a list of all the elements of a mutable array
getAssocs :: (MArray a e m, Ix i) => a i e -> m [(i, e)] Source
Return a list of all the associations of a mutable array, in index order.