content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation and others.
   * 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
   *
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.corext.refactoring.typeconstraints;
  
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.HashSet;
  
  import org.eclipse.core.runtime.Assert;
  
  
  public final class ConstraintOperator {
  	
  	private final String fOperatorString;
  	private final int fOperatorCode;
  
  	private static final int CODE_SUBTYPE= 0;
  	private static final int CODE_EQUALS= 1;
  	private static final int CODE_DEFINES= 2;
  	private static final int CODE_STRICT_SUBTYPE= 3;
  	
  	private static final String STRING_SUBTYPE= "<=";//$NON-NLS-1$
  	private static final String STRING_EQUALS= "==";//$NON-NLS-1$
  	private static final String STRING_DEFINES= "=^=";//$NON-NLS-1$
  	private static final String STRING_STRICT_SUBTYPE= "<";//$NON-NLS-1$
  	private static final Collection fgOperatorStrings= new HashSet(Arrays.asList(new String[] {STRING_SUBTYPE, STRING_EQUALS, STRING_DEFINES, STRING_STRICT_SUBTYPE}));
  
  	private static final ConstraintOperator fgSubtype= new ConstraintOperator(STRING_SUBTYPE, CODE_SUBTYPE);
  	private static final ConstraintOperator fgEquals= new ConstraintOperator(STRING_EQUALS, CODE_EQUALS);
  	private static final ConstraintOperator fgDefines= new ConstraintOperator(STRING_DEFINES, CODE_DEFINES);
  	private static final ConstraintOperator fgStrictSubtype= new ConstraintOperator(STRING_STRICT_SUBTYPE, CODE_STRICT_SUBTYPE);
  
  	public static ConstraintOperator createSubTypeOperator() {
  		return fgSubtype;
  	}
  
  	public static ConstraintOperator createEqualsOperator() {
  		return fgEquals;
  	}
  
  	public static ConstraintOperator createDefinesOperator() {
  		return fgDefines;
  	}
  
  	public static ConstraintOperator createStrictSubtypeOperator() {
  		return fgStrictSubtype;
  	}
  	
  	private ConstraintOperator(String string, int code){
  		Assert.isTrue(fgOperatorStrings.contains(string));
  		Assert.isTrue(code == CODE_DEFINES || code == CODE_EQUALS || code == CODE_STRICT_SUBTYPE || code == CODE_SUBTYPE);
  		fOperatorString= string;
  		fOperatorCode= code;
  	}
  		
  	public String getOperatorString(){
  		return fOperatorString;
  	}
  	
  	/* (non-Javadoc)
  	 * @see java.lang.Object#toString()
  	 */
  	public String toString() {
  		return getOperatorString();
  	}
  		
  	/* (non-Javadoc)
  	 * @see java.lang.Object#equals(java.lang.Object)
  	 */
  	public boolean equals(Object obj) {
  		if (! (obj instanceof ConstraintOperator))
  			return false;
  		ConstraintOperator other= (ConstraintOperator)obj;
  		return fOperatorCode == other.fOperatorCode;
  	}
  
  	/* (non-Javadoc)
  	 * @see java.lang.Object#hashCode()
  	 */
  	public int hashCode() {
  		return fOperatorString.hashCode();
  	}
  
  	public final boolean isSubtypeOperator() {
  		return fOperatorCode == CODE_SUBTYPE;
  	}
  
  	public final boolean isStrictSubtypeOperator() {
  		return fOperatorCode == CODE_STRICT_SUBTYPE;
  	}
  
  	public final boolean isEqualsOperator() {
  		return fOperatorCode == CODE_EQUALS;
  	}
  
  	public final boolean isDefinesOperator() {
  		return fOperatorCode == CODE_DEFINES;
  	}
  }
  