code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM is free software; you can redistribute it and/or modify
  //	it under the terms of the GNU General Public License as published by
  //	the Free Software Foundation; either version 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM is distributed in the hope that it will be useful,
  //	but WITHOUT ANY WARRANTY; without even the implied warranty of
  //	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  //	GNU General Public License for more details.
  //	
  //	You should have received a copy of the GNU General Public License
  //	along with PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package parser.ast;
  
  import parser.Values;
  import prism.OpRelOpBound;
  import prism.PrismException;
  
  /**
   * Abstract class for representing "quantitative" operators (P,R,S),
   * i.e., a superclass of ExpressionProb, ExpressionReward, ExpressionSS.
   */
  public abstract class ExpressionQuant extends Expression
  {
  	/** Optional "modifier" to specify variants of the P/R/S operator */
  	protected String modifier = null;
  	/** The attached relational operator (e.g. "&lt;" in "P&lt;0.1"). */
  	protected RelOp relOp = null;
  	/** The attached (probability/reward) bound, as an expression (e.g. "p" in "P&lt;p"). Null if absent (e.g. "P=?"). */
  	protected Expression bound = null;
  	/** The main operand of the operator (e.g. "F target=true" in "P&lt;0.1[F target=true]. */
  	protected Expression expression = null;
  	/** Optional "old-style" filter. This is just for display purposes since
  	  *  the parser creates an (invisible) new-style filter around this expression. */
  	protected Filter filter = null;
  
  	// Set methods
  
  	/**
  	 * Set the (optional) "modifier" for this operator.
  	 */
  	public void setModifier(String modifier)
  	{
  		this.modifier = modifier;
  	}
  
  	/**
  	 * Set the attached relational operator (e.g. "&lt;" in "P&lt;0.1").
  	 * Uses the enum {@link RelOp}. For example: {@code setRelOp(RelOp.GT);}
  	 */
  	public void setRelOp(RelOp relOp)
  	{
  		this.relOp = relOp;
  	}
  
  	/**
  	 * Set the attached relational operator (e.g. "&lt;" in "P&lt;0.1").
  	 * The operator is passed as a string, e.g. "&lt;" or "&gt;=".
  	 */
  	public void setRelOp(String relOpString)
  	{
  		relOp = RelOp.parseSymbol(relOpString);
  	}
  
  	/**
  	 * Set the attached bound, as an expression (e.g. "p" in "P&lt;p"). Should be null if absent (e.g. "P=?").
  	 */
  	public void setBound(Expression bound)
  	{
  		this.bound = bound;
  	}
  
  	/**
  	 * Set the main operand of the operator (e.g. "F target=true" in "P&lt;0.1[F target=true].
  	 */
  	public void setExpression(Expression expression)
  	{
  		this.expression = expression;
  	}
  
  	/**
  	 * Set the optional "old-style" filter. This is just for display purposes since
  	 * the parser creates an (invisible) new-style filter around this expression.
  	 */
  	public void setFilter(Filter f)
  	{
  		filter = f;
  	}
  
  	// Get methods
  
  	/**
  	 * Get the (optional) "modifier" for this operator.
  	 */
  	public String getModifier()
  	{
  		return modifier;
  	}
  
  	/**
  	 * Get a string representing the modifier as a suffix for the operator.
  	 */
  	public String getModifierString()
  	{
  		return modifier == null ? "" : "(" + modifier + ")";
  	}
  
  	/**
  	 * Get the attached relational operator (e.g. "&lt;" in "P&lt;0.1"), as a {@link RelOp}.
  	 */
  	public RelOp getRelOp()
  	{
  		return relOp;
  	}
  
  	/**
  	 * Get the attached bound, as an expression (e.g. "p" in "P&lt;p"). Should be null if absent (e.g. "P=?").
  	 */
  	public Expression getBound()
  	{
  		return bound;
  	}
  
  	/**
  	 * Get the main operand of the operator (e.g. "F target=true" in "P&lt;0.1[F target=true].
  	 */
  	public Expression getExpression()
  	{
  		return expression;
  	}
  
  	/**
  	 * Get an object storing info about the attached relational operator and bound, after evaluating the bound to a double.
  	 * For example "&lt;0.1" in "P&lt;p" where p=0.5 in {@code constantValues}.
  	 * Does some checks, e.g., throws an exception if a probability is not in the range [0,1]
  	 * 
  	 * @param constantValues Values for constants in order to evaluate any bound
  	 */
  	public abstract OpRelOpBound getRelopBoundInfo(Values constantValues) throws PrismException;
  
  	/**
  	 * Get the optional "old-style" filter. This is just for display purposes since
  	 * the parser creates an (invisible) new-style filter around this expression.
  	 */
  	public Filter getFilter()
  	{
  		return filter;
  	}
  
  	// Standard methods
  	
  	@Override
  	public int hashCode()
  	{
  		final int prime = 31;
  		int result = 1;
  		result = prime * result + ((bound == null) ? 0 : bound.hashCode());
  		result = prime * result + ((expression == null) ? 0 : expression.hashCode());
  		result = prime * result + ((filter == null) ? 0 : filter.hashCode());
  		result = prime * result + ((modifier == null) ? 0 : modifier.hashCode());
  		result = prime * result + ((relOp == null) ? 0 : relOp.hashCode());
  		return result;
  	}
  
  	@Override
  	public boolean equals(Object obj)
  	{
  		if (this == obj)
  			return true;
  		if (obj == null)
  			return false;
  		if (getClass() != obj.getClass())
  			return false;
  		ExpressionQuant other = (ExpressionQuant) obj;
  		if (bound == null) {
  			if (other.bound != null)
  				return false;
  		} else if (!bound.equals(other.bound))
  			return false;
  		if (expression == null) {
  			if (other.expression != null)
  				return false;
  		} else if (!expression.equals(other.expression))
  			return false;
  		if (filter == null) {
  			if (other.filter != null)
  				return false;
  		} else if (!filter.equals(other.filter))
  			return false;
  		if (modifier == null) {
  			if (other.modifier != null)
  				return false;
  		} else if (!modifier.equals(other.modifier))
  			return false;
  		if (relOp != other.relOp)
  			return false;
  		return true;
  	}
  }
  
  //------------------------------------------------------------------------------
  