Data.RandomAccessList
Contents
Description
A random-access list implementation based on Chris Okasaki's approach on his book "Purely Functional Data Structures", Cambridge University Press, 1998, chapter 9.3.
RandomAccessLists are finite lists providing random-access (lookup,
update, etc.) in O(log n) while the list functionality head,
tail and cons still works in O(1).
A RandomAccessList uses Ints for effective indexing. The valid index
range of a RandomAccessList of size n is [0 .. n-1]. If an index is
out of range, an error is raised.
- data RandomAccessList a
- data View a
- = Empty
- | Cons a (RandomAccessList a)
- empty :: RandomAccessList a
- singleton :: a -> RandomAccessList a
- replicate :: Int -> a -> RandomAccessList a
- null :: RandomAccessList a -> Bool
- isEmpty :: RandomAccessList a -> Bool
- length :: RandomAccessList a -> Int
- size :: RandomAccessList a -> Int
- member :: Eq a => a -> RandomAccessList a -> Bool
- index :: Eq a => a -> RandomAccessList a -> Maybe Int
- head :: RandomAccessList a -> a
- tail :: RandomAccessList a -> RandomAccessList a
- uncons :: RandomAccessList a -> (a, RandomAccessList a)
- view :: RandomAccessList a -> View a
- cons :: a -> RandomAccessList a -> RandomAccessList a
- append :: RandomAccessList a -> RandomAccessList a -> RandomAccessList a
- lookup :: Int -> RandomAccessList a -> a
- update :: Int -> a -> RandomAccessList a -> RandomAccessList a
- adjust :: (a -> a) -> Int -> RandomAccessList a -> RandomAccessList a
- adjustLookup :: (a -> a) -> Int -> RandomAccessList a -> (a, RandomAccessList a)
- filter :: (a -> Bool) -> RandomAccessList a -> RandomAccessList a
- partition :: (a -> Bool) -> RandomAccessList a -> (RandomAccessList a, RandomAccessList a)
- zip :: RandomAccessList a -> RandomAccessList b -> RandomAccessList (a, b)
- zipWith :: (a -> b -> c) -> RandomAccessList a -> RandomAccessList b -> RandomAccessList c
- unzip :: RandomAccessList (a, b) -> (RandomAccessList a, RandomAccessList b)
- fromList :: [a] -> RandomAccessList a
- toList :: RandomAccessList a -> [a]
- toIndexedList :: RandomAccessList a -> [(Int, a)]
- toMap :: RandomAccessList a -> Map Int a
- toIntMap :: RandomAccessList a -> IntMap a
- fromArray :: (IArray a e, Ix i) => a i e -> RandomAccessList e
- toArray :: IArray a e => RandomAccessList e -> a Int e
The RandomAccessList type
data RandomAccessList a Source
Random-access lists allowing O(1) list operations and O(log n) indexed access.
Instances
| Functor RandomAccessList | |
| Foldable RandomAccessList | |
| Eq a => Eq (RandomAccessList a) | |
| Ord a => Ord (RandomAccessList a) | |
| Read a => Read (RandomAccessList a) | |
| Show a => Show (RandomAccessList a) | |
| Monoid (RandomAccessList a) |
View the end of a RandomAccessList which is either empty or has
been constructed by head and tail.
Constructors
| Empty | An empty |
| Cons a (RandomAccessList a) |
|
Construction
empty :: RandomAccessList aSource
O(1). Builds an empty RandomAccessList.
singleton :: a -> RandomAccessList aSource
O(1). Builds a singleton RandomAccessList.
replicate :: Int -> a -> RandomAccessList aSource
O(n). replicate n xRandomAccessList that
contains the same element x n times.
Query
null :: RandomAccessList a -> BoolSource
O(1). Is the RandomAccessList empty?
isEmpty :: RandomAccessList a -> BoolSource
O(1). Is the RandomAccessList empty?
length :: RandomAccessList a -> IntSource
O(1). The number of elements contained in a RandomAccessList.
size :: RandomAccessList a -> IntSource
O(1). The number of elements contained in a RandomAccessList.
member :: Eq a => a -> RandomAccessList a -> BoolSource
O(n). Is the given element a member of the RandomAccessList?
List specific operations
head :: RandomAccessList a -> aSource
O(1). Returns the head of a RandomAccessList.
tail :: RandomAccessList a -> RandomAccessList aSource
O(1). Retrieve the tail of a RandomAccessList.
uncons :: RandomAccessList a -> (a, RandomAccessList a)Source
O(1). Retrieve both, head and tail of a RandomAccessList.
view :: RandomAccessList a -> View aSource
O(1). Examine a RandomAccessList: Either it is Empty or it has
a head and a tail (packed in Cons).
cons :: a -> RandomAccessList a -> RandomAccessList aSource
O(1). Prepend an element to the RandomAccessList.
append :: RandomAccessList a -> RandomAccessList a -> RandomAccessList aSource
O(n) where n is the length of the first list. Appends the second
list to the first list.
Random-access specific operations
lookup :: Int -> RandomAccessList a -> aSource
O(log n). Retrieve the ith element of the list. Unless
0 <= i < n, an error is raised.
update :: Int -> a -> RandomAccessList a -> RandomAccessList aSource
O(log n). Set the ith element of the list. Unless
0 <= i < n, an error is raised.
adjust :: (a -> a) -> Int -> RandomAccessList a -> RandomAccessList aSource
O(log n). Adjust ith element of the list according to the
given function. Unless 0 <= i < n, an error is raised.
Arguments
| :: (a -> a) | Modifying element function. |
| -> Int | Index of the affected element. |
| -> RandomAccessList a |
|
| -> (a, RandomAccessList a) | Original element and modified |
O(log n). Find the ith element of the list and change it. This
function returns the element that is at index i in the original
RandomAccessList and a new RandomAccessList with the ith
element replaced according to the given function:
lookup index list === fst (adjustLookup undefined index list)
adjust f index list === snd (adjustLookup f index list)
Unless 0 <= i < n, an error is raised.
Miscellaneous
filter :: (a -> Bool) -> RandomAccessList a -> RandomAccessList aSource
O(n). Remove all elements from a RandomAccessList not fulfilling a
predicate.
partition :: (a -> Bool) -> RandomAccessList a -> (RandomAccessList a, RandomAccessList a)Source
O(n). Split a RandomAccessList into two: The elements in the first
fulfill the given prefix, the others don't.
zip :: RandomAccessList a -> RandomAccessList b -> RandomAccessList (a, b)Source
O(min(n, m)). List-like zip. This function is slightly faster
when called with two RandomAccessLists of equal length.
zipWith :: (a -> b -> c) -> RandomAccessList a -> RandomAccessList b -> RandomAccessList cSource
O(min(n, m)). List-like zipWith. This function is slightly faster
when called with two RandomAccessLists of equal length.
unzip :: RandomAccessList (a, b) -> (RandomAccessList a, RandomAccessList b)Source
O(n). List-like Prelude.unzip for RandomAccessLists.
Conversion
List
fromList :: [a] -> RandomAccessList aSource
O(n). Build a RandomAccessList from a list.
toList :: RandomAccessList a -> [a]Source
O(n). Convert a RandomAccessList to a list.
toIndexedList :: RandomAccessList a -> [(Int, a)]Source
O(n). Convert a RandomAccessList to a list of tuples each holding
an element and its index. The list is ordered ascending regarding the
indices.
Map
toMap :: RandomAccessList a -> Map Int aSource
O(n). Build a Map from a RandomAccessList. The keys in the
Map are the indices of the elements in the RandomAccessList.
toIntMap :: RandomAccessList a -> IntMap aSource
O(n). Build an IntMap from a RandomAccessList. The keys in the
IntMap are the indices of the elements in the RandomAccessList.
Array
fromArray :: (IArray a e, Ix i) => a i e -> RandomAccessList eSource
O(n). Given an IArray, generate a RandomAccessList. The elements'
order will be preserved.
toArray :: IArray a e => RandomAccessList e -> a Int eSource
O(n). Build an IArray from the RandomAccessList. It will have
an index range from [0 .. n-1], where n is the RandomAccessLists
length.