Class PredicateFunction

java.lang.Object
org.apache.commons.functor.adapter.PredicateFunction
All Implemented Interfaces:
Serializable, Function<Boolean>, Functor, NullaryFunctor
public final class PredicateFunction extends Object implements Function<Boolean>, Serializable
Adapts a Predicate to the Function interface.

Note that although this class implements Serializable, a given instance will only be truly Serializable if the underlying predicate is. Attempts to serialize an instance whose delegate is not Serializable will result in an exception.

Version:
$Revision$ $Date$
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      serialVersionUID declaration.
      See Also:

    • predicate

      private final Predicate predicate
      The Predicate I'm wrapping.

  • Constructor Details

    • PredicateFunction

      public PredicateFunction(Predicate predicate)
      Create a new PredicateFunction.
      Parameters:
      predicate - to adapt

  • Method Details

    • evaluate

      public Boolean evaluate()
      Evaluate this function. Returns Boolean.TRUE (Boolean.FALSE) when the test method of my underlying predicate returns true (false).
      Specified by:
      evaluate in interface Function<Boolean>
      Returns:
      a non-null Boolean instance

    • equals

      public boolean equals(Object that)
      Indicates whether some other object is "equal to" this functor. This method must adhere to general Object.equals contract. Additionally, this method can return true only if the specified Object implements the same functor interface and is known to produce the same results and/or side-effects for the same arguments (if any).

      While implementators are strongly encouraged to override the default Object implementation of this method, note that the default Object implementation does in fact adhere to the functor equals contract.

      Specified by:
      equals in interface Functor
      Overrides:
      equals in class Object
      Parameters:
      that - the object to compare this functor to
      Returns:
      true iff the given object implements this functor interface, and is known to produce the same results and/or side-effects for the same arguments (if any).
      See Also:

    • equals

      public boolean equals(PredicateFunction that)
      Learn whether another PredicateFunction is equal to this.
      Parameters:
      that - PredicateFunction to test
      Returns:
      boolean

    • hashCode

      public int hashCode()
      Returns a hash code for this functor adhering to the general Object.hashCode contract. Implementators are strongly encouraged but not strictly required to override the default Object implementation of this method.
      Specified by:
      hashCode in interface Functor
      Overrides:
      hashCode in class Object
      Returns:
      a hash code for this functor
      See Also:

    • toString

      public String toString()
      Returns a human readable description of this functor. Implementators are strongly encouraged but not strictly required to override the default Object implementation of this method.
      Specified by:
      toString in interface Functor
      Overrides:
      toString in class Object
      Returns:
      a human readable description of this functor

    • adapt

      public static PredicateFunction adapt(Predicate predicate)
      Adapt a Predicate to the Function interface.
      Parameters:
      predicate - to adapt
      Returns:
      PredicateFunction