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.visitor;
  
  import parser.ast.*;
  import parser.type.*;
  import prism.PrismLangException;
  
  /**
   * Expand all formulas, return result.
   */
  public class ExpandFormulas extends ASTTraverseModify
  {
  	// The FormulaList for formula definitions
  	private FormulaList formulaList;
  	 // Whether to replace formulas outright with their definition
  	 // (true for use in models since they may be subjected to renaming afterwards;
  	 // false for properties since it is cleaner just to have the name there when displayed)
  	private boolean replace;
  	
  	public ExpandFormulas(FormulaList formulaList, boolean replace)
  	{
  		this.formulaList = formulaList;
  		this.replace = replace;
  	}
  	
  	public Object visit(ExpressionFormula e) throws PrismLangException
  	{
  		int i;
  		Type t;
  		Expression expr;
  		
  		// See if identifier corresponds to a formula
  		i = formulaList.getFormulaIndex(e.getName());
  		if (i != -1) {
  			// If so, replace it with the corresponding expression
  			expr = formulaList.getFormula(i);
  			// But also recursively expand that
  			// (don't clone it to avoid duplication of work)
  			expr = (Expression)expr.expandFormulas(formulaList, replace);
  			// Put in brackets so precedence is preserved
  			// (for display purposes only; in case of re-parse)
  			expr = Expression.Parenth(expr);
  			// This is probably being done before type-checking so
  			// don't really need to preserve type, but do so just in case
  			t = expr.getTypeIfDefined();
  			expr = Expression.Parenth(expr);
  			expr.setType(t);
  			// Return replacement expression
  			// (or just set definition and return)
  			if (replace) {
  				return expr;
  			} else {
  				e.setDefinition(expr);
  				return e;
  			}
  		}
  		
  		// Couldn't find definition - leave unchanged.
  		return e;
  	}
  }
  
  