-- Hoogle documentation, generated by Haddock -- See Hoogle, http://www.haskell.org/hoogle/ -- | Mutable and immutable arrays -- -- This package defines the classes IArray of immutable arrays -- and MArray of arrays mutable within appropriate monads, as -- well as some instances of these classes. @package array @version 0.3.0.1 -- | 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. module Data.Array.MArray -- | 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. class (Monad m) => MArray a e m getBounds :: (MArray a e m, Ix i) => a i e -> m (i, i) newArray :: (MArray a e m, Ix i) => (i, i) -> e -> m (a i e) newArray_ :: (MArray a e m, Ix i) => (i, i) -> m (a i e) -- | 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. newListArray :: (MArray a e m, Ix i) => (i, i) -> [e] -> m (a i e) -- | Read an element from a mutable array readArray :: (MArray a e m, Ix i) => a i e -> i -> m e -- | Write an element in a mutable array writeArray :: (MArray a e m, Ix i) => a i e -> i -> e -> m () -- | Constructs a new array derived from the original array by applying a -- function to each of the elements. mapArray :: (MArray a e' m, MArray a e m, Ix i) => (e' -> e) -> a i e' -> m (a i e) -- | Constructs a new array derived from the original array by applying a -- function to each of the indices. mapIndices :: (MArray a e m, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> m (a i e) -- | Return a list of all the elements of a mutable array getElems :: (MArray a e m, Ix i) => a i e -> m [e] -- | Return a list of all the associations of a mutable array, in index -- order. getAssocs :: (MArray a e m, Ix i) => a i e -> m [(i, e)] -- | Converts a mutable array (any instance of MArray) to an -- immutable array (any instance of IArray) by taking a complete -- copy of it. freeze :: (Ix i, MArray a e m, IArray b e) => a i e -> m (b i e) -- | Converts an mutable array into an immutable array. The implementation -- may either simply cast the array from one type to the other without -- copying the array, or it may take a full copy of the array. -- -- Note that because the array is possibly not copied, any subsequent -- modifications made to the mutable version of the array may be shared -- with the immutable version. It is safe to use, therefore, if the -- mutable version is never modified after the freeze operation. -- -- The non-copying implementation is supported between certain pairs of -- array types only; one constraint is that the array types must have -- identical representations. In GHC, The following pairs of array types -- have a non-copying O(1) implementation of unsafeFreeze. Because -- the optimised versions are enabled by specialisations, you will need -- to compile with optimisation (-O) to get them. -- -- unsafeFreeze :: (Ix i, MArray a e m, IArray b e) => a i e -> m (b i e) -- | Converts an immutable array (any instance of IArray) into a -- mutable array (any instance of MArray) by taking a complete -- copy of it. thaw :: (Ix i, IArray a e, MArray b e m) => a i e -> m (b i e) -- | Converts an immutable array into a mutable array. The implementation -- may either simply cast the array from one type to the other without -- copying the array, or it may take a full copy of the array. -- -- Note that because the array is possibly not copied, any subsequent -- modifications made to the mutable version of the array may be shared -- with the immutable version. It is only safe to use, therefore, if the -- immutable array is never referenced again in this thread, and there is -- no possibility that it can be also referenced in another thread. If -- you use an unsafeThawwriteunsafeFreeze sequence in a -- multi-threaded setting, then you must ensure that this sequence is -- atomic with respect to other threads, or a garbage collector crash may -- result (because the write may be writing to a frozen array). -- -- The non-copying implementation is supported between certain pairs of -- array types only; one constraint is that the array types must have -- identical representations. In GHC, The following pairs of array types -- have a non-copying O(1) implementation of unsafeThaw. Because -- the optimised versions are enabled by specialisations, you will need -- to compile with optimisation (-O) to get them. -- -- unsafeThaw :: (Ix i, IArray a e, MArray b e m) => a i e -> m (b i e) -- | Mutable boxed and unboxed arrays in the IO monad. module Data.Array.IO.Internals -- | An IOArray is a mutable, boxed, non-strict array in the -- IO monad. The type arguments are as follows: -- -- newtype IOArray i e :: * -> * -> * IOArray :: STArray RealWorld i e -> IOArray i e -- | Mutable, unboxed, strict arrays in the IO monad. The type -- arguments are as follows: -- -- newtype IOUArray i e IOUArray :: (STUArray RealWorld i e) -> IOUArray i e -- | Casts an IOUArray 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...). castIOUArray :: IOUArray ix a -> IO (IOUArray ix b) unsafeThawIOUArray :: (Ix ix) => UArray ix e -> IO (IOUArray ix e) instance MArray IOUArray Word64 IO instance MArray IOUArray Word32 IO instance MArray IOUArray Word16 IO instance MArray IOUArray Word8 IO instance MArray IOUArray Int64 IO instance MArray IOUArray Int32 IO instance MArray IOUArray Int16 IO instance MArray IOUArray Int8 IO instance MArray IOUArray (StablePtr a) IO instance MArray IOUArray Double IO instance MArray IOUArray Float IO instance MArray IOUArray (FunPtr a) IO instance MArray IOUArray (Ptr a) IO instance MArray IOUArray Word IO instance MArray IOUArray Int IO instance MArray IOUArray Char IO instance MArray IOUArray Bool IO instance Eq (IOUArray i e) instance Typeable2 IOUArray -- | Mutable boxed and unboxed arrays in the IO monad. module Data.Array.IO -- | An IOArray is a mutable, boxed, non-strict array in the -- IO monad. The type arguments are as follows: -- -- data IOArray i e :: * -> * -> * -- | Mutable, unboxed, strict arrays in the IO monad. The type -- arguments are as follows: -- -- data IOUArray i e -- | Casts an IOUArray 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...). castIOUArray :: IOUArray ix a -> IO (IOUArray ix b) -- | Reads a number of Word8s from the specified Handle -- directly into an array. hGetArray :: Handle -> IOUArray Int Word8 -> Int -> IO Int -- | Writes an array of Word8 to the specified Handle. hPutArray :: Handle -> IOUArray Int Word8 -> Int -> IO () -- | Mutable boxed and unboxed arrays in the ST monad. module Data.Array.ST -- | Mutable, boxed, non-strict arrays in the ST monad. The type -- arguments are as follows: -- -- data STArray s 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. runSTArray :: (Ix i) => (forall s. ST s (STArray s i e)) -> Array i e -- | A mutable array with unboxed elements, that can be manipulated in the -- ST monad. The type arguments are as follows: -- -- -- -- 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. data STUArray s 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. runSTUArray :: (Ix i) => (forall s. ST s (STUArray s i e)) -> UArray i e -- | 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...). castSTUArray :: STUArray s ix a -> ST s (STUArray s ix b) -- | A storable array is an IO-mutable array which stores its contents in a -- contiguous memory block living in the C heap. Elements are stored -- according to the class Storable. You can obtain the pointer to -- the array contents to manipulate elements from languages like C. -- -- It is similar to Data.Array.IO.IOUArray but slower. Its -- advantage is that it's compatible with C. module Data.Array.Storable -- | The array type data StorableArray i e -- | The pointer to the array contents is obtained by -- withStorableArray. The idea is similar to ForeignPtr -- (used internally here). The pointer should be used only during -- execution of the IO action retured by the function passed as -- argument to withStorableArray. withStorableArray :: StorableArray i e -> (Ptr e -> IO a) -> IO a -- | If you want to use it afterwards, ensure that you -- touchStorableArray after the last use of the pointer, so the -- array is not freed too early. touchStorableArray :: StorableArray i e -> IO () -- | Construct a StorableArray from an arbitrary ForeignPtr. -- It is the caller's responsibility to ensure that the ForeignPtr -- points to an area of memory sufficient for the specified bounds. unsafeForeignPtrToStorableArray :: (Ix i) => ForeignPtr e -> (i, i) -> IO (StorableArray i e) instance (Storable e) => MArray StorableArray e IO -- | Basic non-strict arrays. -- -- Note: The Data.Array.IArray module provides a more -- general interface to immutable arrays: it defines operations with the -- same names as those defined below, but with more general types, and -- also defines Array instances of the relevant classes. To use -- that more general interface, import Data.Array.IArray but not -- Data.Array. module Data.Array -- | The type of immutable non-strict (boxed) arrays with indices in -- i and elements in e. The Int is the number of -- elements in the Array. data (Ix i) => Array i e :: * -> * -> * -- | Construct an array with the specified bounds and containing values for -- given indices within these bounds. -- -- The array is undefined (i.e. bottom) if any index in the list is out -- of bounds. The Haskell 98 Report further specifies that if any two -- associations in the list have the same index, the value at that index -- is undefined (i.e. bottom). However in GHC's implementation, the value -- at such an index is the value part of the last association with that -- index in the list. -- -- Because the indices must be checked for these errors, array is -- strict in the bounds argument and in the indices of the association -- list, but nonstrict in the values. Thus, recurrences such as the -- following are possible: -- -- a = array (1,100) ((1,1) : [(i, i * a!(i-1)) | i <- [2..100]]) -- -- -- Not every index within the bounds of the array need appear in the -- association list, but the values associated with indices that do not -- appear will be undefined (i.e. bottom). -- -- If, in any dimension, the lower bound is greater than the upper bound, -- then the array is legal, but empty. Indexing an empty array always -- gives an array-bounds error, but bounds still yields the bounds -- with which the array was constructed. array :: (Ix i) => (i, i) -> [(i, e)] -> Array i e -- | Construct an array from a pair of bounds and a list of values in index -- order. listArray :: (Ix i) => (i, i) -> [e] -> Array i e -- | The accumArray deals with repeated indices in the association -- list using an accumulating function which combines the values -- of associations with the same index. For example, given a list of -- values of some index type, hist produces a histogram of the -- number of occurrences of each index within a specified range: -- -- hist :: (Ix a, Num b) => (a,a) -> [a] -> Array a b hist -- bnds is = accumArray (+) 0 bnds [(i, 1) | i<-is, inRange bnds i] -- -- -- If the accumulating function is strict, then accumArray is -- strict in the values, as well as the indices, in the association list. -- Thus, unlike ordinary arrays built with array, accumulated -- arrays should not in general be recursive. accumArray :: (Ix i) => (e -> a -> e) -> e -> (i, i) -> [(i, a)] -> Array i e -- | The value at the given index in an array. (!) :: (Ix i) => Array i e -> i -> e -- | The bounds with which an array was constructed. bounds :: (Ix i) => Array i e -> (i, i) -- | The list of indices of an array in ascending order. indices :: (Ix i) => Array i e -> [i] -- | The list of elements of an array in index order. elems :: (Ix i) => Array i e -> [e] -- | The list of associations of an array in index order. assocs :: (Ix i) => Array i e -> [(i, e)] -- | Constructs an array identical to the first argument except that it has -- been updated by the associations in the right argument. For example, -- if m is a 1-origin, n by n matrix, then -- -- m//[((i,i), 0) | i <- [1..n]] -- -- is the same matrix, except with the diagonal zeroed. -- -- Repeated indices in the association list are handled as for -- array: Haskell 98 specifies that the resulting array is -- undefined (i.e. bottom), but GHC's implementation uses the last -- association for each index. (//) :: (Ix i) => Array i e -> [(i, e)] -> Array i e -- | accum f takes an array and an association list and -- accumulates pairs from the list into the array with the accumulating -- function f. Thus accumArray can be defined using -- accum: -- -- accumArray f z b = accum f (array b [(i, z) | i <- range b]) -- accum :: (Ix i) => (e -> a -> e) -> Array i e -> [(i, a)] -> Array i e -- | ixmap allows for transformations on array indices. It may be -- thought of as providing function composition on the right with the -- mapping that the original array embodies. -- -- A similar transformation of array values may be achieved using -- fmap from the Array instance of the Functor -- class. ixmap :: (Ix i, Ix j) => (i, i) -> (i -> j) -> Array j e -> Array i e -- | Immutable arrays, with an overloaded interface. For array types which -- can be used with this interface, see the Array type exported by -- this module and the Data.Array.Unboxed module. Other packages, -- such as diffarray, also provide arrays using this interface. module Data.Array.IArray -- | Class of immutable 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 IArray class is parameterised over both -- a and e, so that instances specialised to certain -- element types can be defined. class IArray a e bounds :: (IArray a e, Ix i) => a i e -> (i, i) -- | The type of immutable non-strict (boxed) arrays with indices in -- i and elements in e. The Int is the number of -- elements in the Array. data (Ix i) => Array i e :: * -> * -> * -- | Constructs an immutable array from a pair of bounds and a list of -- initial associations. -- -- The bounds are specified as a pair of the lowest and highest bounds in -- the array respectively. For example, a one-origin vector of length 10 -- has bounds (1,10), and a one-origin 10 by 10 matrix has bounds -- ((1,1),(10,10)). -- -- An association is a pair of the form (i,x), which defines the -- value of the array at index i to be x. The array is -- undefined if any index in the list is out of bounds. If any two -- associations in the list have the same index, the value at that index -- is implementation-dependent. (In GHC, the last value specified for -- that index is used. Other implementations will also do this for -- unboxed arrays, but Haskell 98 requires that for Array the -- value at such indices is bottom.) -- -- Because the indices must be checked for these errors, array is -- strict in the bounds argument and in the indices of the association -- list. Whether array is strict or non-strict in the elements -- depends on the array type: Data.Array.Array is a non-strict -- array type, but all of the Data.Array.Unboxed.UArray arrays -- are strict. Thus in a non-strict array, recurrences such as the -- following are possible: -- -- 
--   a = array (1,100) ((1,1) : [(i, i * a!(i-1)) | i \<- [2..100]])
--
-- -- Not every index within the bounds of the array need appear in the -- association list, but the values associated with indices that do not -- appear will be undefined. -- -- If, in any dimension, the lower bound is greater than the upper bound, -- then the array is legal, but empty. Indexing an empty array always -- gives an array-bounds error, but bounds still yields the bounds -- with which the array was constructed. array :: (IArray a e, Ix i) => (i, i) -> [(i, e)] -> a i e -- | Constructs an immutable array from a list of initial elements. The -- list gives the elements of the array in ascending order beginning with -- the lowest index. listArray :: (IArray a e, Ix i) => (i, i) -> [e] -> a i e -- | Constructs an immutable array from a list of associations. Unlike -- array, the same index is allowed to occur multiple times in the -- list of associations; an accumulating function is used to -- combine the values of elements with the same index. -- -- For example, given a list of values of some index type, hist produces -- a histogram of the number of occurrences of each index within a -- specified range: -- -- 
--   hist :: (Ix a, Num b) => (a,a) -> [a] -> Array a b
--   hist bnds is = accumArray (+) 0 bnds [(i, 1) | i\<-is, inRange bnds i]
--
accumArray :: (IArray a e, Ix i) => (e -> e' -> e) -> e -> (i, i) -> [(i, e')] -> a i e -- | Returns the element of an immutable array at the specified index. (!) :: (IArray a e, Ix i) => a i e -> i -> e -- | Returns a list of all the valid indices in an array. indices :: (IArray a e, Ix i) => a i e -> [i] -- | Returns a list of all the elements of an array, in the same order as -- their indices. elems :: (IArray a e, Ix i) => a i e -> [e] -- | Returns the contents of an array as a list of associations. assocs :: (IArray a e, Ix i) => a i e -> [(i, e)] -- | Takes an array and a list of pairs and returns an array identical to -- the left argument except that it has been updated by the associations -- in the right argument. For example, if m is a 1-origin, n by n matrix, -- then m//[((i,i), 0) | i <- [1..n]] is the same matrix, -- except with the diagonal zeroed. -- -- As with the array function, if any two associations in the list -- have the same index, the value at that index is -- implementation-dependent. (In GHC, the last value specified for that -- index is used. Other implementations will also do this for unboxed -- arrays, but Haskell 98 requires that for Array the value at -- such indices is bottom.) -- -- For most array types, this operation is O(n) where n is -- the size of the array. However, the diffarray package provides an -- array type for which this operation has complexity linear in the -- number of updates. (//) :: (IArray a e, Ix i) => a i e -> [(i, e)] -> a i e -- | accum f takes an array and an association list and -- accumulates pairs from the list into the array with the accumulating -- function f. Thus accumArray can be defined using -- accum: -- -- 
--   accumArray f z b = accum f (array b [(i, z) | i \<- range b])
--
accum :: (IArray a e, Ix i) => (e -> e' -> e) -> a i e -> [(i, e')] -> a i e -- | Returns a new array derived from the original array by applying a -- function to each of the elements. amap :: (IArray a e', IArray a e, Ix i) => (e' -> e) -> a i e' -> a i e -- | Returns a new array derived from the original array by applying a -- function to each of the indices. ixmap :: (IArray a e, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> a i e -- | Unboxed immutable arrays. module Data.Array.Unboxed -- | Arrays with unboxed elements. Instances of IArray are provided -- for UArray with certain element types (Int, -- Float, Char, etc.; see the UArray class for a -- full list). -- -- A UArray will generally be more efficient (in terms of both -- time and space) than the equivalent Data.Array.Array with the -- same element type. However, UArray is strict in its elements - -- so don't use UArray if you require the non-strictness that -- Data.Array.Array provides. -- -- Because the IArray interface provides operations overloaded -- on the type of the array, it should be possible to just change the -- array type being used by a program from say Array to -- UArray to get the benefits of unboxed arrays (don't forget to -- import Data.Array.Unboxed instead of Data.Array). data UArray i e