/*
 * The Apache Software License, Version 1.1
 * 
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 * 
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache\@apache.org.
 * 
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation, and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/**
 * $Log$
 * Revision 1.1  1999/11/09 01:03:05  twl
 * Initial revision
 *
 * Revision 1.2  1999/11/08 20:45:36  rahul
 * Swat for adding in Product name and CVS comment log variable.
 *
 */

#if !defined(CMNODE_HPP)
#define CMNODE_HPP

#include <util/XML4CDefs.hpp>
#include <validators/DTD/ContentSpecNode.hpp>
#include <validators/DTD/CMStateSet.hpp>


class CMNode
{
public :
    // -----------------------------------------------------------------------
    //  Constructors and Destructors
    // -----------------------------------------------------------------------
    CMNode(const ContentSpecNode::NodeTypes type);
    virtual ~CMNode();


    // -----------------------------------------------------------------------
    //  Virtual methods to be provided derived node classes
    // -----------------------------------------------------------------------
    virtual bool isNullable() const = 0;


    // -----------------------------------------------------------------------
    //  Getter methods
    // -----------------------------------------------------------------------
    ContentSpecNode::NodeTypes getType() const;
    const CMStateSet& getFirstPos() const;
    const CMStateSet& getLastPos() const;


    // -----------------------------------------------------------------------
    //  Setter methods
    // -----------------------------------------------------------------------
    void setMaxStates(const unsigned int maxStates);


protected :
    // -----------------------------------------------------------------------
    //  Protected, abstract methods
    // -----------------------------------------------------------------------
    virtual void calcFirstPos(CMStateSet& toUpdate) const = 0;
    virtual void calcLastPos(CMStateSet& toUpdate) const = 0;


private :
    // -----------------------------------------------------------------------
    //  Unimplemented constructors and operators
    // -----------------------------------------------------------------------
    CMNode();
    CMNode(const CMNode&);
    void operator=(const CMNode&);


    // -----------------------------------------------------------------------
    //  Private data members
    //
    //  fType
    //      The type of node. This indicates whether its a leaf or an
    //      operation.
    //
    //  fFirstPos
    //      The set of NFA states that represent the entry states of this
    //      node in the DFA.
    //
    //  fLastPos
    //      The set of NFA states that represent the final states of this
    //      node in the DFA.
    //
    //  fMaxStates
    //      The maximum number of states that the NFA has, which means the
    //      max number of NFA states that have to be traced in the state
    //      sets during the building of the DFA. Its unfortunate that it
    //      has to be stored redundantly, but we need to fault in the
    //      state set members and they have to be sized to this size.
    // -----------------------------------------------------------------------
    ContentSpecNode::NodeTypes  fType;
    CMStateSet*                 fFirstPos;
    CMStateSet*                 fLastPos;
    unsigned int                fMaxStates;
}; 


// ---------------------------------------------------------------------------
//  CMNode: Constructors and Destructors
// ---------------------------------------------------------------------------
inline CMNode::CMNode(const ContentSpecNode::NodeTypes type) :

    fType(type)
    , fFirstPos(0)
    , fLastPos(0)
    , fMaxStates(-1)
{
}

inline CMNode::~CMNode()
{
    // Clean up any position sets that got created
    delete fFirstPos;
    delete fLastPos;
}


// ---------------------------------------------------------------------------
//  CMNode: Getter methods
// ---------------------------------------------------------------------------
inline ContentSpecNode::NodeTypes CMNode::getType() const
{
    return fType;
}

inline const CMStateSet& CMNode::getFirstPos() const
{
    //
    //  Fault in the state set if needed. Since we can't use mutable members
    //  cast off the const'ness.
    //
    if (!fFirstPos)
    {
        CMNode* unconstThis = (CMNode*)this;
        unconstThis->fFirstPos = new CMStateSet(fMaxStates);
        unconstThis->calcFirstPos(*fFirstPos);
    }
    return *fFirstPos;
}

inline const CMStateSet& CMNode::getLastPos() const
{
    //
    //  Fault in the state set if needed. Since we can't use mutable members
    //  cast off the const'ness.
    //
    if (!fLastPos)
    {
        CMNode* unconstThis = (CMNode*)this;
        unconstThis->fLastPos = new CMStateSet(fMaxStates);
        unconstThis->calcLastPos(*fLastPos);
    }
    return *fLastPos;
}


// ---------------------------------------------------------------------------
//  CMNode: Setter methods
// ---------------------------------------------------------------------------
inline void CMNode::setMaxStates(const unsigned int maxStates)
{
    fMaxStates = maxStates;
}

#endif