Package 

Class BidirectionalMap

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public class BidirectionalMap<T extends Object, R extends Object>

    A bidirectional map. Each key-value-pair gets mapped in both directions. Keys and values must be unique in the sense that there must not be a duplicate key in the domain, nor a duplicate value in the coDomain, but the same element may appear once as key and once as value.

    Example:

    A -> B

    A -> C

    is invalid because A is contained twice in the Domain.<br>

    A -> B

    C -> B

    is invalid because B is contained twice in the coDomain.<br>

    A -> B

    C -> A

    is valid because A is only contained once in the domain and in the coDomain.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private final Integer size

    • Constructor Summary

      Constructors 
      Constructor Description
      BidirectionalMap(Pair<T, R> elements) Creates a map with the given set of elements mapping pair first -> pair.second.

    • Method Summary

      Modifier and Type Method Description
      final Integer getSize()
      final Boolean add(T entity, R value) Adds a relation A -> B if domain does not contain A and coDomain does not contain B.
      final Boolean add(Pair<T, R> element) Adds a relation A -> B if domain does not contain A and coDomain does not contain B.
      final Boolean addAll(Pair<T, R> items) Adds all relations A -> B.
      final R forward(T entity) Forward lookup for entry.
      final R forwardOrNull(T entity) Forward lookup for entry.
      final T backward(R value) Backward lookup for entry.
      final T backwardOrNull(R value) Backward lookup for entry.
      final Boolean remove(T entity, R value) Removes relation A -> B if it exists.
      final Boolean remove(Pair<T, R> element) Removes relation A -> B if it exists.
      final Boolean removeForward(T entity) Removes by forward lookup.
      final Boolean removeBackward(R value) Removes by backward lookup.
      final Boolean contains(T entity, R value) Returns whether relation A -> B exists in this map.
      final Boolean contains(Pair<T, R> pair) Returns whether relation A -> B exists in this map.
      final Boolean containsForward(T entity) Returns whether a relation A -> * exists.
      final Boolean containsBackward(R value) Returns whether a relation * -> B exists.
      final Set<T> getDomain() Returns the domain of this map as a set.
      final Set<R> getCoDomain() Returns the coDomain of this map as a set.
      final Unit clear() Clears the map.
      final Boolean isEmpty() Returns whether this map contains no elements.
      final Boolean isNotEmpty() Returns whether this map contains elements.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • BidirectionalMap

        BidirectionalMap(Pair<T, R> elements)
        Creates a map with the given set of elements mapping pair first -> pair.second.
        Parameters:
        elements - Elements to be initialized in the map.

    • Method Detail

      • add

         final Boolean add(T entity, R value)

        Adds a relation A -> B if domain does not contain A and coDomain does not contain B. Returns false if the relation could not be added.

      • add

         final Boolean add(Pair<T, R> element)

        Adds a relation A -> B if domain does not contain A and coDomain does not contain B. Returns false if the relation could not be added.

      • addAll

         final Boolean addAll(Pair<T, R> items)

        Adds all relations A -> B. If any of the given items already exist, it gets ignored. If any item contains a key or value that already exists, the map remains unchanged.

        Example: Map: (A->B), (C->D)

        addAll(E->F),(G->H) results in (A->B), (C->D), (E->F),(G->H) : true

        addAll(A->B),(E->F) results in (A->B), (C->D), (E->F), : true

        addAll(A->C),(E->F) results in (A->B), (C->D) : false

      • forward

         final R forward(T entity)

        Forward lookup for entry.

        Parameters:
        entity - Relation key.

      • forwardOrNull

         final R forwardOrNull(T entity)

        Forward lookup for entry.

        Parameters:
        entity - Relation key.

      • backward

         final T backward(R value)

        Backward lookup for entry.

        Parameters:
        value - Relation value.

      • backwardOrNull

         final T backwardOrNull(R value)

        Backward lookup for entry.

        Parameters:
        value - Relation value.

      • remove

         final Boolean remove(T entity, R value)

        Removes relation A -> B if it exists.

        Parameters:
        entity - Relation key A.
        value - Relation value B.

      • remove

         final Boolean remove(Pair<T, R> element)

        Removes relation A -> B if it exists.

        Parameters:
        element - Pair (Relation key A, Relation value B)

      • removeForward

         final Boolean removeForward(T entity)

        Removes by forward lookup. Removes relation A -> * if it exists.

        Parameters:
        entity - Relation key A.

      • removeBackward

         final Boolean removeBackward(R value)

        Removes by backward lookup. Removes relation * -> B.

        Parameters:
        value - Relation value B.

      • contains

         final Boolean contains(T entity, R value)

        Returns whether relation A -> B exists in this map.

        Parameters:
        entity - Relation key A.
        value - Relation value B.

      • contains

         final Boolean contains(Pair<T, R> pair)

        Returns whether relation A -> B exists in this map.

        Parameters:
        pair - Relation pair A -> B.

      • containsForward

         final Boolean containsForward(T entity)

        Returns whether a relation A -> * exists.

        Parameters:
        entity - Relation key A.

      • containsBackward

         final Boolean containsBackward(R value)

        Returns whether a relation * -> B exists.

        Parameters:
        value - Relation value B.

      • getDomain

         final Set<T> getDomain()

        Returns the domain of this map as a set.

      • getCoDomain

         final Set<R> getCoDomain()

        Returns the coDomain of this map as a set.

      • isEmpty

         final Boolean isEmpty()

        Returns whether this map contains no elements.