Copyright | 2011 Bryan O'Sullivan |
---|---|

License | BSD-style |

Maintainer | johan.tibell@gmail.com |

Stability | provisional |

Portability | portable |

Safe Haskell | Trustworthy |

Language | Haskell98 |

A set of *hashable* values. A set cannot contain duplicate items.
A `HashSet`

makes no guarantees as to the order of its elements.

The implementation is based on *hash array mapped trie*. A
`HashSet`

is often faster than other tree-based set types,
especially when value comparison is expensive, as in the case of
strings.

Many operations have a average-case complexity of *O(log n)*. The
implementation uses a large base (i.e. 16) so in practice these
operations are constant time.

## Synopsis

- data HashSet a
- empty :: HashSet a
- singleton :: Hashable a => a -> HashSet a
- union :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a
- unions :: (Eq a, Hashable a) => [HashSet a] -> HashSet a
- null :: HashSet a -> Bool
- size :: HashSet a -> Int
- member :: (Eq a, Hashable a) => a -> HashSet a -> Bool
- insert :: (Eq a, Hashable a) => a -> HashSet a -> HashSet a
- delete :: (Eq a, Hashable a) => a -> HashSet a -> HashSet a
- map :: (Hashable b, Eq b) => (a -> b) -> HashSet a -> HashSet b
- difference :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a
- intersection :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a
- foldl' :: (a -> b -> a) -> a -> HashSet b -> a
- foldr :: (b -> a -> a) -> a -> HashSet b -> a
- filter :: (a -> Bool) -> HashSet a -> HashSet a
- toList :: HashSet a -> [a]
- fromList :: (Eq a, Hashable a) => [a] -> HashSet a
- toMap :: HashSet a -> HashMap a ()
- fromMap :: HashMap a () -> HashSet a

# Documentation

A set of values. A set cannot contain duplicate values.

## Instances

Foldable HashSet # | |

Defined in Data.HashSet fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |

Eq1 HashSet # | |

Ord1 HashSet # | |

Defined in Data.HashSet | |

Show1 HashSet # | |

Hashable1 HashSet # | |

Defined in Data.HashSet | |

(Eq a, Hashable a) => IsList (HashSet a) # | |

Eq a => Eq (HashSet a) # | |

(Data a, Eq a, Hashable a) => Data (HashSet a) # | |

Defined in Data.HashSet gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashSet a -> c (HashSet a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashSet a) # toConstr :: HashSet a -> Constr # dataTypeOf :: HashSet a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashSet a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashSet a)) # gmapT :: (forall b. Data b => b -> b) -> HashSet a -> HashSet a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQ :: (forall d. Data d => d -> u) -> HashSet a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> HashSet a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # | |

Ord a => Ord (HashSet a) # | |

Defined in Data.HashSet | |

(Eq a, Hashable a, Read a) => Read (HashSet a) # | |

Show a => Show (HashSet a) # | |

(Hashable a, Eq a) => Semigroup (HashSet a) # | |

(Hashable a, Eq a) => Monoid (HashSet a) # | |

NFData a => NFData (HashSet a) # | |

Defined in Data.HashSet | |

Hashable a => Hashable (HashSet a) # | |

Defined in Data.HashSet | |

type Item (HashSet a) # | |

Defined in Data.HashSet |

# Construction

# Combine

union :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a #

*O(n+m)* Construct a set containing all elements from both sets.

To obtain good performance, the smaller set must be presented as the first argument.

unions :: (Eq a, Hashable a) => [HashSet a] -> HashSet a #

Construct a set containing all elements from a list of sets.

# Basic interface

insert :: (Eq a, Hashable a) => a -> HashSet a -> HashSet a #

*O(log n)* Add the specified value to this set.

delete :: (Eq a, Hashable a) => a -> HashSet a -> HashSet a #

*O(log n)* Remove the specified value from this set if
present.

# Transformations

map :: (Hashable b, Eq b) => (a -> b) -> HashSet a -> HashSet b #

*O(n)* Transform this set by applying a function to every value.
The resulting set may be smaller than the source.

# Difference and intersection

difference :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a #

*O(n)* Difference of two sets. Return elements of the first set
not existing in the second.

intersection :: (Eq a, Hashable a) => HashSet a -> HashSet a -> HashSet a #

*O(n)* Intersection of two sets. Return elements present in both
the first set and the second.

# Folds

foldl' :: (a -> b -> a) -> a -> HashSet b -> a #

*O(n)* Reduce this set by applying a binary operator to all
elements, using the given starting value (typically the
left-identity of the operator). Each application of the operator
is evaluated before before using the result in the next
application. This function is strict in the starting value.

foldr :: (b -> a -> a) -> a -> HashSet b -> a #

*O(n)* Reduce this set by applying a binary operator to all
elements, using the given starting value (typically the
right-identity of the operator).

# Filter

filter :: (a -> Bool) -> HashSet a -> HashSet a #

*O(n)* Filter this set by retaining only elements satisfying a
predicate.

# Conversions

## Lists

fromList :: (Eq a, Hashable a) => [a] -> HashSet a #

*O(n*min(W, n))* Construct a set from a list of elements.