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//==============================================================================
//
// 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 constants, return result.
*/
public class ExpandConstants extends ASTTraverseModify
{
private ConstantList constantList;
public ExpandConstants(ConstantList constantList)
{
this.constantList = constantList;
}
public Object visit(ExpressionConstant e) throws PrismLangException
{
int i;
Type t;
Expression expr;
// See if identifier corresponds to a constant
i = constantList.getConstantIndex(e.getName());
if (i != -1) {
// And check that the constant is defined
if (constantList.getConstant(i) != null) {
// If so, replace it with the corresponding expression
expr = constantList.getConstant(i).deepCopy();
// But also recursively expand that
expr = (Expression) expr.expandConstants(constantList);
// Put in brackets so precedence is preserved
// (for display purposes only; in case of re-parse)
// This is being done after type-checking so also set type
t = expr.getType();
expr = Expression.Parenth(expr);
expr.setType(t);
// Return replacement expression
return expr;
}
else {
// Error (should never happen)
throw new PrismLangException("Undefined constant", e);
}
}
else {
// Error (should never happen)
throw new PrismLangException("Undefined constant", e);
}
}
}