code: /**
   * <copyright>
   * Copyright (c) 2010-2014 Henshin developers. All rights reserved. 
   * This program and the accompanying materials are made available 
   * under the terms of the Eclipse Public License v1.0 which 
   * accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   * </copyright>
   */
  package org.eclipse.emf.henshin.interpreter.matching.constraints;
  
  /**
   * Interface for unary constraints.
   * 
   * @author Enrico Biermann Christian Krause
   */
  public interface UnaryConstraint extends Constraint {
  	
  	/**
  	 * Evaluates this constraint on the given domain slot. Unary constraints may
  	 * be checked at any time.
  	 * @param slot The domain slot the constraint will be evaluated on.
  	 * @return <code>true</code>, if the constraint is valid.
  	 */
  	boolean check(DomainSlot slot);
  	
  }
  