array-0.3.0.2: Mutable and immutable arrays

Portability | non-portable (uses Data.Array.MArray)
Stability | experimental
Maintainer | libraries@haskell.org

Data.Array.ST

Contents

- Boxed arrays
- Unboxed arrays
- Overloaded mutable array interface

Description

Mutable boxed and unboxed arrays in the `ST` monad.

Synopsis

- data STArray s i e
- runSTArray :: Ix i => (forall s. ST s (STArray s i e)) -> Array i e
- data STUArray s i e
- runSTUArray :: Ix i => (forall s. ST s (STUArray s i e)) -> UArray i e
- castSTUArray :: STUArray s ix a -> ST s (STUArray s ix b)
- module Data.Array.MArray

# Boxed arrays

data STArray s i e Source

Mutable, boxed, non-strict arrays in the `ST` monad. The type arguments are as follows:

- `s`: the state variable argument for the `ST` type
- `i`: the index type of the array (should be an instance of `Ix`)
- `e`: the element type of the array.

Instances

Typeable3 STArray |
MArray (STArray s) e (ST s) |
MArray (STArray s) e (ST s) |
Eq (STArray s i e) |

runSTArray :: Ix i => (forall s. ST s (STArray s i e)) -> Array i e

A safe way to create and work with a mutable array before returning an immutable array for later perusal. This function avoids copying the array before returning it - it uses `unsafeFreeze` internally, but this wrapper is a safe interface to that function.

# Unboxed arrays

data STUArray s i e

A mutable array with unboxed elements, that can be manipulated in the `ST` monad. The type arguments are as follows:

- `s`: the state variable argument for the `ST` type
- `i`: the index type of the array (should be an instance of `Ix`)
- `e`: the element type of the array. Only certain element types are supported.

An `STUArray` will generally be more efficient (in terms of both time and space) than the equivalent boxed version (`STArray`) with the same element type. However, `STUArray` is strict in its elements - so don't use `STUArray` if you require the non-strictness that `STArray` provides.

Instances

Typeable3 STUArray |
MArray (STUArray s) Word64 (ST s) |
MArray (STUArray s) Word32 (ST s) |
MArray (STUArray s) Word16 (ST s) |
MArray (STUArray s) Word8 (ST s) |
MArray (STUArray s) Int64 (ST s) |
MArray (STUArray s) Int32 (ST s) |
MArray (STUArray s) Int16 (ST s) |
MArray (STUArray s) Int8 (ST s) |
MArray (STUArray s) Double (ST s) |
MArray (STUArray s) Float (ST s) |
MArray (STUArray s) Word (ST s) |
MArray (STUArray s) Int (ST s) |
MArray (STUArray s) Char (ST s) |
MArray (STUArray s) Bool (ST s) |
MArray (STUArray s) (StablePtr a) (ST s) |
MArray (STUArray s) (FunPtr a) (ST s) |
MArray (STUArray s) (Ptr a) (ST s) |
Eq (STUArray s i e) |

runSTUArray :: Ix i => (forall s. ST s (STUArray s i e)) -> UArray i e

A safe way to create and work with an unboxed mutable array before returning an immutable array for later perusal. This function avoids copying the array before returning it - it uses `unsafeFreeze` internally, but this wrapper is a safe interface to that function.

castSTUArray :: STUArray s ix a -> ST s (STUArray s ix b)

Casts an `STUArray` with one element type into one with a different element type. All the elements of the resulting array are undefined (unless you know what you're doing...).

# Overloaded mutable array interface

module Data.Array.MArray