Package it.unimi.dsi.fastutil.objects

Interface Object2BooleanFunction<K>

All Superinterfaces:
Function<K,​java.lang.Boolean>, java.util.function.Function<K,​java.lang.Boolean>, java.util.function.Predicate<K>
All Known Subinterfaces:
Object2BooleanMap<K>, Object2BooleanSortedMap<K>
All Known Implementing Classes:
AbstractObject2BooleanFunction, AbstractObject2BooleanMap, AbstractObject2BooleanSortedMap, Object2BooleanArrayMap, Object2BooleanAVLTreeMap, Object2BooleanFunctions.EmptyFunction, Object2BooleanFunctions.PrimitiveFunction, Object2BooleanFunctions.Singleton, Object2BooleanFunctions.SynchronizedFunction, Object2BooleanFunctions.UnmodifiableFunction, Object2BooleanLinkedOpenCustomHashMap, Object2BooleanLinkedOpenHashMap, Object2BooleanMaps.EmptyMap, Object2BooleanMaps.Singleton, Object2BooleanMaps.SynchronizedMap, Object2BooleanMaps.UnmodifiableMap, Object2BooleanOpenCustomHashMap, Object2BooleanOpenHashMap, Object2BooleanRBTreeMap, Object2BooleanSortedMaps.EmptySortedMap, Object2BooleanSortedMaps.Singleton, Object2BooleanSortedMaps.SynchronizedSortedMap, Object2BooleanSortedMaps.UnmodifiableSortedMap
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 interface Object2BooleanFunction<K>
extends Function<K,​java.lang.Boolean>, java.util.function.Predicate<K>
A type-specific Function; provides some additional methods that use polymorphism to avoid (un)boxing.

Type-specific versions of get(), put() and remove() cannot rely on null to denote absence of a key. Rather, they return a default return value, which is set to 0/false at creation, but can be changed using the defaultReturnValue() method.

For uniformity reasons, even functions returning objects implement the default return value (of course, in this case the default return value is initialized to null).

The default implementation of optional operations just throw an UnsupportedOperationException, except for the type-specific containsKey(), which return true. Generic versions of accessors delegate to the corresponding type-specific counterparts following the interface rules.

Warning: to fall in line as much as possible with the standard map interface, it is required that standard versions of get(), put() and remove() for maps with primitive-type keys or values return null to denote missing keys rather than wrap the default return value in an object. In case both keys and values are reference types, the default return value must be returned instead, thus violating the standard map interface when the default return value is not null.

See Also:
Function

  • Method Details

    • test

      default boolean test​(K operand)
      Specified by:
      test in interface java.util.function.Predicate<K>
      Since:
      8.0.0

    • put

      default boolean put​(K key, boolean value)
      Adds a pair to the map (optional operation).
      Parameters:
      key - the key.
      value - the value.
      Returns:
      the old value, or the default return value if no value was present for the given key.
      See Also:
      Function.put(Object,Object)

    • getBoolean

      boolean getBoolean​(java.lang.Object key)
      Returns the value to which the given key is mapped.
      Parameters:
      key - the key.
      Returns:
      the corresponding value, or the default return value if no value was present for the given key.
      See Also:
      Function.get(Object)

    • getOrDefault

      default boolean getOrDefault​(java.lang.Object key, boolean defaultValue)
      Returns the value associated by this function to the specified key, or give the specified value if not present.
      Parameters:
      key - the key.
      defaultValue - the value to return if not present.
      Returns:
      the corresponding value, or defaultValue if no value was present for the given key.
      Since:
      8.5.0
      See Also:
      Function.getOrDefault(Object, Object)

    • removeBoolean

      default boolean removeBoolean​(java.lang.Object key)
      Removes the mapping with the given key (optional operation).
      Parameters:
      key - the key.
      Returns:
      the old value, or the default return value if no value was present for the given key.
      See Also:
      Function.remove(Object)

    • put

      @Deprecated default java.lang.Boolean put​(K key, java.lang.Boolean value)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Associates the specified value with the specified key in this function (optional operation).
      Specified by:
      put in interface Function<K,​java.lang.Boolean>
      Parameters:
      key - the key.
      value - the value.
      Returns:
      the old value, or null if no value was present for the given key.
      See Also:
      Map.put(Object,Object)

    • get

      @Deprecated default java.lang.Boolean get​(java.lang.Object key)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Returns the value associated by this function to the specified key.
      Specified by:
      get in interface Function<K,​java.lang.Boolean>
      Parameters:
      key - the key.
      Returns:
      the corresponding value, or null if no value was present for the given key.
      See Also:
      Map.get(Object)

    • getOrDefault

      @Deprecated default java.lang.Boolean getOrDefault​(java.lang.Object key, java.lang.Boolean defaultValue)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Returns the value associated by this function to the specified key, or give the specified value if not present.
      Specified by:
      getOrDefault in interface Function<K,​java.lang.Boolean>
      Parameters:
      key - the key.
      defaultValue - the default value to return if not present.
      Returns:
      the corresponding value, or defaultValue if no value was present for the given key.
      See Also:
      Map.getOrDefault(Object, Object)

    • remove

      @Deprecated default java.lang.Boolean remove​(java.lang.Object key)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Removes this key and the associated value from this function if it is present (optional operation).
      Specified by:
      remove in interface Function<K,​java.lang.Boolean>
      Parameters:
      key - the key.
      Returns:
      the old value, or null if no value was present for the given key.
      See Also:
      Map.remove(Object)

    • defaultReturnValue

      default void defaultReturnValue​(boolean rv)
      Sets the default return value (optional operation). This value must be returned by type-specific versions of get(), put() and remove() to denote that the map does not contain the specified key. It must be 0/false/null by default.
      Parameters:
      rv - the new default return value.
      See Also:
      defaultReturnValue()

    • defaultReturnValue

      default boolean defaultReturnValue()
      Gets the default return value.

      This default implementation just return the default null value of the type (null for objects, 0 for scalars, false for Booleans).

      Returns:
      the current default return value.

    • andThen

      @Deprecated default <T> java.util.function.Function<K,​T> andThen​(java.util.function.Function<? super java.lang.Boolean,​? extends T> after)
      Deprecated.
      Please use the corresponding type-specific method instead.
      Specified by:
      andThen in interface java.util.function.Function<K,​java.lang.Boolean>

    • andThenByte

      default Object2ByteFunction<K> andThenByte​(Boolean2ByteFunction after)

    • composeByte

      default Byte2BooleanFunction composeByte​(Byte2ObjectFunction<K> before)

    • andThenShort

      default Object2ShortFunction<K> andThenShort​(Boolean2ShortFunction after)

    • composeShort

      default Short2BooleanFunction composeShort​(Short2ObjectFunction<K> before)

    • andThenInt

      default Object2IntFunction<K> andThenInt​(Boolean2IntFunction after)

    • composeInt

      default Int2BooleanFunction composeInt​(Int2ObjectFunction<K> before)

    • andThenLong

      default Object2LongFunction<K> andThenLong​(Boolean2LongFunction after)

    • composeLong

      default Long2BooleanFunction composeLong​(Long2ObjectFunction<K> before)

    • andThenChar

      default Object2CharFunction<K> andThenChar​(Boolean2CharFunction after)

    • composeChar

      default Char2BooleanFunction composeChar​(Char2ObjectFunction<K> before)

    • andThenFloat

      default Object2FloatFunction<K> andThenFloat​(Boolean2FloatFunction after)

    • composeFloat

      default Float2BooleanFunction composeFloat​(Float2ObjectFunction<K> before)

    • andThenDouble

      default Object2DoubleFunction<K> andThenDouble​(Boolean2DoubleFunction after)

    • composeDouble

      default Double2BooleanFunction composeDouble​(Double2ObjectFunction<K> before)

    • andThenObject

      default <T> Object2ObjectFunction<K,​T> andThenObject​(Boolean2ObjectFunction<? extends T> after)

    • composeObject

      default <T> Object2BooleanFunction<T> composeObject​(Object2ObjectFunction<? super T,​? extends K> before)

    • andThenReference

      default <T> Object2ReferenceFunction<K,​T> andThenReference​(Boolean2ReferenceFunction<? extends T> after)

    • composeReference

      default <T> Reference2BooleanFunction<T> composeReference​(Reference2ObjectFunction<? super T,​? extends K> before)