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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.ast;
import parser.*;
import parser.visitor.*;
import prism.PrismLangException;
public class ExpressionExists extends Expression
{
Expression expression = null;
// Constructors
public ExpressionExists()
{
}
public ExpressionExists(Expression e)
{
expression = e;
}
// Set methods
public void setExpression(Expression e)
{
expression = e;
}
// Get methods
public Expression getExpression()
{
return expression;
}
// Methods required for Expression:
/**
* Is this expression constant?
*/
public boolean isConstant()
{
return false;
}
/**
* Evaluate this expression, return result.
* Note: assumes that type checking has been done already.
*/
public Object evaluate(Values constantValues, Values varValues) throws PrismLangException
{
throw new PrismLangException("Cannot evaluate an E operator without a model");
}
// Methods required for ASTElement:
/**
* Visitor method.
*/
public Object accept(ASTVisitor v) throws PrismLangException
{
return v.visit(this);
}
/**
* Convert to string.
*/
public String toString()
{
String s = "";
s += "E [ " + expression + " ]";
return s;
}
/**
* Perform a deep copy.
*/
public Expression deepCopy()
{
ExpressionExists expr = new ExpressionExists(expression.deepCopy());
expr.setType(type);
expr.setPosition(this);
return expr;
}
}
//------------------------------------------------------------------------------