edu.umd.cloud9.util.map
Interface MapKL<K>

Type Parameters:

K - type of the keys

All Known Implementing Classes:

HMapKL

public interface MapKL<K>

Map from arbitrary objects to longs.

Nested Class Summary

static interface

MapKL.Entry<K> A map entry (key-value pair) for MapKL.

Method Summary

void	clear() Removes all of the mappings from this map.
boolean	containsKey(K key) Returns true if this map contains a mapping for the specified key.
boolean	containsValue(long value) Returns true if this map contains one or more mappings with the specified value.
Set<MapKL.Entry<K>>	entrySet() Returns a Set view of the mappings contained in this map.
boolean	equals(Object o) Compares the specified object with this map for equality.
long	get(K key) Returns the value to which the specified key is mapped, or throws NoSuchElementException if this map contains no mapping for the key.
int	hashCode() Returns the hash code value for this map.
boolean	isEmpty() Returns true if this map contains no key-value mappings.
Set<K>	keySet() Returns a Set view of the keys contained in this map.
void	put(K key, long value) Associates the specified value with the specified key in this map.
void	putAll(MapKL<? extends K> m) Copies all of the mappings from the specified map to this map.
long	remove(K key) Removes the mapping for a key from this map if it is present.
int	size() Returns the number of key-value mappings in this map.
Collection<Long>	values() Returns a Collection view of the values contained in this map.

Method Detail

size

int size()

Returns the number of key-value mappings in this map.

Returns:

the number of key-value mappings in this map

isEmpty

boolean isEmpty()

Returns true if this map contains no key-value mappings.

Returns:

true if this map contains no key-value mappings

containsKey

boolean containsKey(K key)

Returns true if this map contains a mapping for the specified key.

Parameters:

key - key whose presence in this map is to be tested

Returns:

true if this map contains a mapping for the specified key

containsValue

boolean containsValue(long value)

Returns true if this map contains one or more mappings with the specified value.

Parameters:

value - value whose presence in this map is to be tested

Returns:

true this map contains one or more mappings with the specified value

get

long get(K key)

Returns the value to which the specified key is mapped, or throws NoSuchElementException if this map contains no mapping for the key.

Parameters:

key - the key whose associated value is to be returned

Returns:

the value to which the specified key is mapped

Throws:

NoSuchElementException - if the key is not contained in this map

put

void put(K key,
         long value)

Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced by the specified value.

Parameters:

key - key with which the specified value is to be associated

value - value to be associated with the specified key

remove

long remove(K key)

Removes the mapping for a key from this map if it is present. No action is performed if this map does not contain the key.

Parameters:

key - key whose mapping is to be removed from the map

putAll

void putAll(MapKL<? extends K> m)

Copies all of the mappings from the specified map to this map.

Parameters:

m - mappings to be stored in this map

clear

void clear()

Removes all of the mappings from this map. The map will be empty after this call returns.

keySet

Set<K> keySet()

Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. See Map.keySet() for more details.

Returns:

a set view of the keys contained in this map

values

Collection<Long> values()

Returns a Collection view of the values contained in this map. Note that this is a inefficient operation since it triggers autoboxing of the long values, which is exactly what this implementation is trying to avoid. Unlike a standard Java Map, values in the backing map cannot be altered with this collection view.

Returns:

a collection view of the values contained in this map

entrySet

Set<MapKL.Entry<K>> entrySet()

Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. See Map.entrySet() for more details.

Returns:

a set view of the mappings contained in this map

equals

boolean equals(Object o)

Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings if m1.entrySet().equals(m2.entrySet()). This ensures that the equals method works properly across different implementations of the MapKL interface.

Overrides:

equals in class Object

Parameters:

o - object to be compared for equality with this map

Returns:

true if the specified object is equal to this map

hashCode

int hashCode()

Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's entrySet() view. This ensures that m1.equals(m2) implies that m1.hashCode()==m2.hashCode() for any two maps m1 and m2, as required by the general contract of Object.hashCode().

Overrides:

hashCode in class Object

Returns:

the hash code value for this map

See Also:

MapKL.Entry.hashCode(), Object.equals(Object), equals(Object)