/*

 */

/*

 *

 *

 */

package com.sun.org.apache.xerces.internal.impl.dtd.models;

/**

 * A content model node.

 *

 * @xerces.internal

 *

 */

public abstract class CMNode

{

    // -------------------------------------------------------------------

    //  Constructors

    // -------------------------------------------------------------------

    public CMNode(int type)

    {

        fType = type;

    }

    // -------------------------------------------------------------------

    //  Package, abstract methods

    // -------------------------------------------------------------------

    // made this public so it could be implemented and used outside this package -neilg.

    public abstract boolean isNullable() ;

    // -------------------------------------------------------------------

    //  Package final methods

    // -------------------------------------------------------------------

    public final int type()

    {

        return fType;

    }

    // made this public so it could be implemented and used outside this package -neilg.

    public final CMStateSet firstPos()

    {

        if (fFirstPos == null)

        {

            fFirstPos = new CMStateSet(fMaxStates);

            calcFirstPos(fFirstPos);

        }

        return fFirstPos;

    }

    // made this public so it could be implemented and used outside this package -neilg.

    public final CMStateSet lastPos()

    {

        if (fLastPos == null)

        {

            fLastPos = new CMStateSet(fMaxStates);

            calcLastPos(fLastPos);

        }

        return fLastPos;

    }

    final void setFollowPos(CMStateSet setToAdopt)

    {

        fFollowPos = setToAdopt;

    }

    public final void setMaxStates(int maxStates)

    {

        fMaxStates = maxStates;

    }

    /**

     * Allows the user to set arbitrary data on this content model

     * node. This is used by the a{n,m} optimization that runs

     * in constant space.

     */

    public void setUserData(Object userData) {

        fUserData = userData;

    }

    /**

     * Allows the user to get arbitrary data set on this content

     * model node. This is used by the a{n,m} optimization that runs

     * in constant space.

     */

    public Object getUserData() {

        return fUserData;

    }

    // -------------------------------------------------------------------

    //  Protected, abstract methods

    // -------------------------------------------------------------------

    protected abstract void calcFirstPos(CMStateSet toSet) ;

    protected abstract void calcLastPos(CMStateSet toSet) ;

    // -------------------------------------------------------------------

    //  Private data members

    //

    //  fType

    //      The type of node. This indicates whether its a leaf or an

    //      operation. Though we also do derived classes for these types,

    //      it is too expensive to use runtime typing to find this out.

    //      This is one of the ContentSpecNode.NODE_XXX types.

    //

    //  fFirstPos

    //      The set of NFA states that represent the entry states of this

    //      node in the DFA.

    //

    //  fFollowPos

    //      The set of NFA states that can be gotten to from from 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. We

    //      init to to -1 so it will cause an error if its used without

    //      being initialized.

    // -------------------------------------------------------------------

    private Object      fUserData   = null;

};