content: /*
   * Copyright (c) 2016-2020, the Alpha Team.
   * All rights reserved.
   *
   * Additional changes made by Siemens.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1) Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2) Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package at.ac.tuwien.kr.alpha.core.common;
  
  import static at.ac.tuwien.kr.alpha.core.programs.atoms.Literals.atomOf;
  import static at.ac.tuwien.kr.alpha.core.programs.atoms.Literals.isNegated;
  
  import java.util.Iterator;
  
  import at.ac.tuwien.kr.alpha.api.programs.atoms.Atom;
  import at.ac.tuwien.kr.alpha.core.solver.AtomCounter;
  
  /**
   * Translates atoms between integer (solver) and object (grounder) representation.
   */
  public interface AtomStore {
  
  	/**
  	 * Returns true whenever the atom is a valid choice point (i.e., it represents a rule body).
  	 * @param atom
  	 * @return
  	 */
  	boolean isAtomChoicePoint(int atom);
  
  	/**
  	 * Returns the highest atomId in use.
  	 * @return the highest atomId in use.
  	 */
  	int getMaxAtomId();
  
  	/**
  	 * Translates an atom represented as int into an Atom object.
  	 * @param atom the atom to translate.
  	 * @return the Atom object represented by the int.
  	 */
  	Atom get(int atom);
  
  	/**
  	 * Translates an atom represented as Atom object into an int.
  	 * @param atom the Atom object to translate.
  	 * @return the int representing the Atom object.
  	 */
  	int get(Atom atom);
  
  	/**
  	 * If the given ground atom is not already stored, associates it with a new integer (ID) and stores it, else
  	 * returns the current associated atom ID. Hence, multiple calls with the same parameter will return the same
  	 * value.
  	 * @param groundAtom the ground atom to look up in the store.
  	 * @return the integer ID of the ground atom, possibly newly assigned.
  	 */
  	int putIfAbsent(Atom groundAtom);
  
  	/**
  	 * Returns whether the given ground atom is known to the AtomStore.
  	 * @param groundAtom the ground atom to test.
  	 * @return true if the ground atom is already associated an integer ID.
  	 */
  	boolean contains(Atom groundAtom);
  
  	String atomToString(int atom);
  
  	default String literalToString(int literal) {
  		return (isNegated(literal) ? "-" : "+") + "(" + atomToString(atomOf(literal)) + ")";
  	}
  
  	/**
  	 * Prints the NoGood such that literals are structured atoms instead of integers.
  	 * @param noGood the nogood to translate
  	 * @return the string representation of the NoGood.
  	 */
  	default <T extends NoGoodInterface> String noGoodToString(T noGood) {
  		StringBuilder sb = new StringBuilder();
  
  		if (noGood.hasHead()) {
  			sb.append("*");
  		}
  		sb.append("{");
  
  		for (Iterator<Integer> iterator = noGood.iterator(); iterator.hasNext();) {
  			sb.append(literalToString(iterator.next()));
  
  			if (iterator.hasNext()) {
  				sb.append(", ");
  			}
  		}
  
  		sb.append("}");
  
  		return sb.toString();
  	}
  
  	AtomCounter getAtomCounter();
  }
  