com.koloboke.collect.map
Interface ObjObjMap<K,V>

All Superinterfaces:

Container, Map<K,V>

All Known Subinterfaces:

HashObjObjMap<K,V>

public interface ObjObjMap<K,V>
extends Map<K,V>, Container

The library's extension of the classic Map interface.

See Also:

ObjObjMapFactory, @KolobokeMap

Nested Class Summary

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Method Summary

V	compute(K key, BiFunction<? super K,? super V,? extends V> remappingFunction) Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).
V	computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null.
V	computeIfPresent(K key, BiFunction<? super K,? super V,? extends V> remappingFunction) If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
ObjObjCursor<K,V>	cursor() Returns a new cursor over the entries of this map.
ObjSet<Map.Entry<K,V>>	entrySet() Returns a Set view of the mappings contained in this map.
void	forEach(BiConsumer<? super K,? super V> action) Performs the given action on each entry in this map until all entries have been processed or the action throws an Exception.
boolean	forEachWhile(BiPredicate<? super K,? super V> predicate) Checks the given predicate on each entry in this map until all entries have been processed or the predicate returns false for some entry, or throws an Exception.
V	getOrDefault(Object key, V defaultValue) Returns the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key.
Equivalence<K>	keyEquivalence() Returns the equivalence strategy for keys in this map.
ObjSet<K>	keySet() Returns a Set view of the keys contained in this map.
V	merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction) If the specified key is not already associated with a value (or is mapped to null), associates it with the given value, otherwise, replaces the value with the results of the given remapping function.
V	putIfAbsent(K key, V value) If the specified key is not already associated with a value (or is mapped to null), associates it with the given value and returns null, else returns the current value.
boolean	remove(Object key, Object value) Removes the entry for the specified key only if it is currently mapped to the specified value.
boolean	removeIf(BiPredicate<? super K,? super V> filter) Removes all of the entries of this collection that satisfy the given predicate.
V	replace(K key, V value) Replaces the entry for the specified key only if it is currently mapped to some value.
boolean	replace(K key, V oldValue, V newValue) Replaces the entry for the specified key only if currently mapped to the specified value.
void	replaceAll(BiFunction<? super K,? super V,? extends V> function) Replaces each entry's value with the result of invoking the given function on that entry, in the order entries are returned by an entry set iterator, until all entries have been processed or the function throws an exception.
Equivalence<V>	valueEquivalence() Returns the equivalence strategy for values in this map.
ObjCollection<V>	values() Returns a Collection view of the values contained in this map.

Methods inherited from interface Map

clear, containsKey, containsValue, equals, get, hashCode, isEmpty, put, putAll, remove, size

Methods inherited from interface com.koloboke.collect.Container

clear, ensureCapacity, isEmpty, shrink, size, sizeAsLong

Method Detail

keyEquivalence

@Nonnull
Equivalence<K> keyEquivalence()

Returns the equivalence strategy for keys in this map. All methods in the Map interface which defined in terms of Object.equals(Object) equality of key objects (almost all methods, actually), are supposed to use this equivalence instead.

Returns:

the equivalence strategy for keys in this map

See Also:

HashObjObjMapFactory.withKeyEquivalence(com.koloboke.collect.Equivalence)

valueEquivalence

@Nonnull
Equivalence<V> valueEquivalence()

Returns the equivalence strategy for values in this map. All methods in the Map interface which defined in terms of Object.equals(Object) equality of value objects, for example, Map.containsValue(Object) and remove(Object, Object), are supposed to use this equivalence instead.

Returns:

the equivalence strategy for values in this map

See Also:

ObjObjMapFactory.withValueEquivalence(com.koloboke.collect.Equivalence)

getOrDefault

V getOrDefault(Object key,
               V defaultValue)

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

Parameters:

key - the key whose associated value is to be returned

defaultValue - the value to return if the specified key is absent in the map

Returns:

the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key

Throws:

ClassCastException - if the key is of an inappropriate type for this map (optional restriction)

NullPointerException - if the specified key is null and this map does not permit null keys (optional restriction)

forEach

void forEach(@Nonnull
             BiConsumer<? super K,? super V> action)

Performs the given action on each entry in this map until all entries have been processed or the action throws an Exception. Exceptions thrown by the action are relayed to the caller. The entries will be processed in the same order as the entry set iterator unless that order is unspecified in which case implementations may use an order which differs from the entry set iterator.

Parameters:

action - The action to be performed for each entry

See Also:

Comparison of iteration options in the library

forEachWhile

boolean forEachWhile(@Nonnull
                     BiPredicate<? super K,? super V> predicate)

Checks the given predicate on each entry in this map until all entries have been processed or the predicate returns false for some entry, or throws an Exception. Exceptions thrown by the predicate are relayed to the caller.

The entries will be processed in the same order as the entry set iterator unless that order is unspecified in which case implementations may use an order which differs from the entry set iterator.

If the map is empty, this method returns true immediately.

Parameters:

predicate - the predicate to be checked for each entry

Returns:

true if the predicate returned true for all entries of the map, false if it returned false for the entry

See Also:

Comparison of iteration options in the library

cursor

@Nonnull
ObjObjCursor<K,V> cursor()

Returns a new cursor over the entries of this map. It's order is always correspond to the entry set iterator order.

Basic cursor usage idiom is:

for (ObjObjCursor<K, V> cur = map.cursor(); cur.moveNext();) {
     // Work with cur.key() and cur.value()
     // Call cur.remove() to remove the current entry
 }

Returns:

a new cursor over the entries of this map

See Also:

Comparison of iteration options in the library

keySet

@Nonnull
ObjSet<K> keySet()

Description copied from interface: java.util.Map

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. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Specified by:

keySet in interface Map<K,V>

Returns:

a set view of the keys contained in this map

values

@Nonnull
ObjCollection<V> values()

Description copied from interface: java.util.Map

Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Specified by:

values in interface Map<K,V>

Returns:

a collection view of the values contained in this map

entrySet

@Nonnull
ObjSet<Map.Entry<K,V>> entrySet()

Description copied from interface: java.util.Map

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. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Specified by:

entrySet in interface Map<K,V>

Returns:

a set view of the mappings contained in this map

putIfAbsent

@Nullable
V putIfAbsent(K key,
                       V value)

If the specified key is not already associated with a value (or is mapped to null), associates it with the given value and returns null, else returns the current value.

Parameters:

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

value - value to be associated with the specified key

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports such values.)

Throws:

UnsupportedOperationException - if the put operation is not supported by this map

ClassCastException - if the class of the specified key or value prevents it from being stored in this map

NullPointerException - if the specified key or value is null, and this map does not permit null keys or values * @throws IllegalArgumentException if some property of a specified key or value prevents it from being stored in this map

compute

V compute(K key,
          @Nonnull
          BiFunction<? super K,? super V,? extends V> remappingFunction)

Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).

If the function returns null, the mapping is removed (or remains absent if initially absent).

If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

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

remappingFunction - the function to compute a value

Returns:

the new value associated with the specified key or if the specified key is null and this map does not support null keys

Throws:

ClassCastException - if the class of the specified key or computed value prevents it from being stored in this map (optional restriction)

UnsupportedOperationException - if the put operation is not supported by this map

computeIfAbsent

V computeIfAbsent(K key,
                  @Nonnull
                  Function<? super K,? extends V> mappingFunction)

If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null. The most common usage is to construct a new object serving as an initial mapped value or memoized result.

If the function returns null no mapping is recorded.

If the function itself throws an (unchecked) exception, the exception is rethrown, and no mapping is recorded.

Parameters:

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

mappingFunction - the function to compute a value

Returns:

the current (existing or computed) value associated with the specified key or if the specified key is null and this map does not support null keys

Throws:

ClassCastException - if the class of the specified key or computed value prevents it from being stored in this map (optional restriction)

UnsupportedOperationException - if the put operation is not supported by this map

computeIfPresent

V computeIfPresent(K key,
                   @Nonnull
                   BiFunction<? super K,? super V,? extends V> remappingFunction)

If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.

If the function returns null, the mapping is removed.

If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

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

remappingFunction - the function to compute a value

Returns:

the new value associated with the specified key, or "no entry" value or if the specified key is null and this map does not support null keys

Throws:

ClassCastException - if the class of the specified key or computed value prevents it from being stored in this map (optional restriction)

UnsupportedOperationException - if the put operation is not supported by this map

merge

V merge(K key,
        V value,
        @Nonnull
        BiFunction<? super V,? super V,? extends V> remappingFunction)

If the specified key is not already associated with a value (or is mapped to null), associates it with the given value, otherwise, replaces the value with the results of the given remapping function. This method may be of use when combining multiple mapped values for a key.

If the function returns null, the mapping is removed.

If the remappingFunction itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

Parameters:

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

value - the value to use if absent

remappingFunction - the function to recompute a value if present

Returns:

the new value associated with the specified key

Throws:

NullPointerException - if the remappingFunction is null or if the specified key is null and this map does not support null keys or if the specified value is null and this map does not support null values

ClassCastException - if the class of the specified key or computed value prevents it from being stored in this map (optional restriction)

UnsupportedOperationException - if the put operation is not supported by this map

replace

@Nullable
V replace(K key,
                   V value)

Replaces the entry for the specified key only if it is currently mapped to some value.

Parameters:

key - key with which the specified value is associated

value - value to be associated with the specified key

Returns:

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports such values.)

Throws:

ClassCastException - if the class of the specified key or value prevents it from being stored in this map

NullPointerException - if the specified key or value is null, and this map does not permit null keys or values * @throws IllegalArgumentException if some property of a specified key or value prevents it from being stored in this map

UnsupportedOperationException - if the put operation is not supported by this map

replace

boolean replace(K key,
                V oldValue,
                V newValue)

Replaces the entry for the specified key only if currently mapped to the specified value.

Parameters:

key - key with which the specified value is associated

oldValue - value expected to be associated with the specified key

newValue - value to be associated with the specified key

Returns:

true if the value was replaced

Throws:

ClassCastException - if the class of the specified key or value prevents it from being stored in this map

NullPointerException - if the specified key or value is null, and this map does not permit null keys or values * @throws IllegalArgumentException if some property of a specified key or value prevents it from being stored in this map

UnsupportedOperationException - if the put operation is not supported by this map

replaceAll

void replaceAll(@Nonnull
                BiFunction<? super K,? super V,? extends V> function)

Replaces each entry's value with the result of invoking the given function on that entry, in the order entries are returned by an entry set iterator, until all entries have been processed or the function throws an exception.

Parameters:

function - the function to apply to each entry

Throws:

UnsupportedOperationException - if the set operation is not supported by this map's entry set iterator or the specified replacement value is null, and this map does not permit null values (optional restriction)

ClassCastException - if the class of a replacement value prevents it from being stored in this map

IllegalArgumentException - if some property of a replacement value prevents it from being stored in this map (optional restriction)

remove

boolean remove(Object key,
               Object value)

Removes the entry for the specified key only if it is currently mapped to the specified value.

Parameters:

key - key with which the specified value is associated

value - value expected to be associated with the specified key

Returns:

true if the value was removed

Throws:

ClassCastException - if the class of the specified key or value prevents it from being stored in this map (optional restriction)

NullPointerException - if the specified key or value is null, and this map does not permit null key or values (optional restriction)

UnsupportedOperationException - if the remove operation is not supported by this map

removeIf

boolean removeIf(@Nonnull
                 BiPredicate<? super K,? super V> filter)

Removes all of the entries of this collection that satisfy the given predicate. Errors or runtime exceptions thrown during iteration or by the predicate are relayed to the caller.

Parameters:

filter - a predicate which returns true for elements to be removed

Returns:

true if any elements were removed

Throws:

NullPointerException - if the specified filter is null

UnsupportedOperationException - if elements cannot be removed from this collection. Implementations may throw this exception if a matching element cannot be removed or if, in general, removal is not supported.

See Also:

Comparison of iteration options in the library