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GATE - general achitecture for text engineering - is open source software capable of solving almost any text processing problem. This artifact enables you to embed the core GATE Embedded with its essential dependencies. You will able to use the GATE Embedded API and load and store GATE XML documents. This artifact is the perfect dependency for CREOLE plugins or for applications that need to customize the GATE dependencies due to confict with their own dependencies or for lower footprint.

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/*
 *  Copyright (c) 1995-2012, The University of Sheffield. See the file
 *  COPYRIGHT.txt in the software or at http://gate.ac.uk/gate/COPYRIGHT.txt
 *
 *  This file is part of GATE (see http://gate.ac.uk/), and is free
 *  software, licenced under the GNU Library General Public License,
 *  Version 2, June 1991 (in the distribution as file licence.html,
 *  and also available at http://gate.ac.uk/gate/licence.html).
 *
 *  Johann Petrak 2009-08-20
 *
 *  $Id: OValue.java 15333 2012-02-07 13:18:33Z ian_roberts $
 */
package gate.creole.ontology;

/**
 * A class representing something that is either a literal or a OResource.
 * 
 * Developer note: ideally this would be implemented as a superinteface
 * of the Literal and OResource interfaces, but Literal is implemented
 * as a class and has to remain a class for backwards compatibility.löschnaz
 * 
 * @author Johann Petrak
 */
// TODO: should we implement comparable and equals/hashcode for this?
public interface OValue  {

  /**
   * Check if the object represents a literal.
   *
   * @return true if the object represents a literal value, false if it
   * represents a blank node ID or an URI.
   */
  public boolean isLiteral();

  /**
   * Check if the object represents a OResource
   *
   * @return true if the object represents a OResource object
   */
  public boolean isOResource();

  /**
   * Get the {@link OResource} object if this object represents a resource. Throws a
   * {@link GateOntologyException} if this object represents a literal.
   *
   * @return  the OResource represented by this object
   */
  public OResource getOResource();

  /**
   * Get the {@link Literal} object if this object represents a literal.
   * Throws a {@link GateOntologyException} if this object represents a
   * node ID.
   *
   * @return the Literal represented by this object
   */
  public Literal getLiteral();
  @Override
  /**
   * Create a String representation of the represented object.
   *
   */
  public String toString();
  /**
   * Create a String representation that conforms to Turtle language syntax.
   * If this represents a OResource it is identical to OResource.toString()
   *
   * @return a string representation of the node id or literal following
   * Turtle syntax.
   */
  public String toTurtle();

  @Override
  public int hashCode();

  @Override
  public boolean equals(Object other);

}