com.devexperts.util

Interface IndexerFunction.IdentityKey<K,V>

All Superinterfaces:

IndexerFunction<K,V>, Serializable

All Known Implementing Classes:

IdentityIndexer, IndexerFunction.DefaultIdentityKey

Enclosing interface:

IndexerFunction<K,V>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface IndexerFunction.IdentityKey<K,V>
extends IndexerFunction<K,V>

A specialized IndexerFunction that distinguishes and identifies elements using identity comparison of object keys.

It uses System.identityHashCode(Object) method instead of Object.hashCode() method to compute hashcode and reference comparison instead of Object.equals(Object) method to determine identity.

In order to use this functional interface, cast a lambda expression to it when creating IndexedSet. For example,
IndexedSet<Key, Value> set = IndexedSet.create((IndexerFunction.IdentityKey<Key, Value>)Value::getKey);

Nested Class Summary

Nested classes/interfaces inherited from interface com.devexperts.util.IndexerFunction

IndexerFunction.DefaultIdentityKey, IndexerFunction.DefaultIndexerFunction, IndexerFunction.IdentityKey<K,V>, IndexerFunction.IntKey<V>, IndexerFunction.LongKey<V>

Field Summary

Fields inherited from interface com.devexperts.util.IndexerFunction

DEFAULT, DEFAULT_IDENTITY_KEY

Method Summary

Modifier and Type	Method and Description
default int	hashCodeByKey(K key) Returns hash code for specified object key; called when performing operations using object keys.
default boolean	matchesByKey(K key, V value) Determines if specified object key matches specified value; called when performing operations using object keys.

Methods inherited from interface com.devexperts.util.IndexerFunction

getNumberKey, getObjectKey, hashCodeByKey, hashCodeByValue, matchesByKey, matchesByValue

Method Detail

hashCodeByKey

default int hashCodeByKey(K key)

Returns hash code for specified object key; called when performing operations using object keys.

This implementation delegates to System.identityHashCode(key) expression.

Specified by:

hashCodeByKey in interface IndexerFunction<K,V>

matchesByKey

default boolean matchesByKey(K key,
                             V value)

Determines if specified object key matches specified value; called when performing operations using object keys.

This implementation delegates to (key == getObjectKey(value)) expression.

Specified by:

matchesByKey in interface IndexerFunction<K,V>