JJTIDLParserState.java

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2001 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.modules.corba.idl.src;

class JJTIDLParserState {
    /**
     * @associates Node 
     */
    private java.util.Stack nodes;

    /**
     * @associates Integer 
     */
    private java.util.Stack marks;

    private int sp;		// number of nodes on stack
    private int mk;		// current mark
    private boolean node_created;

    JJTIDLParserState() {
        nodes = new java.util.Stack();
        marks = new java.util.Stack();
        sp = 0;
        mk = 0;
    }

    /* Determines whether the current node was actually closed and
       pushed.  This should only be called in the final user action of a
       node scope.  */
    boolean nodeCreated() {
        return node_created;
    }

    /* Call this to reinitialize the node stack.  It is called
       automatically by the parser's ReInit() method. */
    void reset() {
        nodes.removeAllElements();
        marks.removeAllElements();
        sp = 0;
        mk = 0;
    }

    /* Returns the root node of the AST.  It only makes sense to call
       this after a successful parse. */
    Node rootNode() {
        return (Node)nodes.elementAt(0);
    }

    /* Pushes a node on to the stack. */
    void pushNode(Node n) {
        nodes.push(n);
        ++sp;
    }

    /* Returns the node on the top of the stack, and remove it from the
       stack.  */
    Node popNode() {
        if (--sp < mk) {
            mk = ((Integer)marks.pop()).intValue();
        }
        return (Node)nodes.pop();
    }

    /* Returns the node currently on the top of the stack. */
    Node peekNode() {
        return (Node)nodes.peek();
    }

    /* Returns the number of children on the stack in the current node
       scope. */
    int nodeArity() {
        return sp - mk;
    }


    void clearNodeScope(Node n) {
        while (sp > mk) {
            popNode();
        }
        mk = ((Integer)marks.pop()).intValue();
    }


    void openNodeScope(Node n) {
        marks.push(new Integer(mk));
        mk = sp;
        n.jjtOpen();
    }


    /* A definite node is constructed from a specified number of
       children.  That number of nodes are popped from the stack and
       made the children of the definite node.  Then the definite node
       is pushed on to the stack. */
    void closeNodeScope(Node n, int num) {
        mk = ((Integer)marks.pop()).intValue();
        while (num-- > 0) {
            Node c = popNode();
            c.jjtSetParent(n);
            n.jjtAddChild(c, num);
        }
        n.jjtClose();
        pushNode(n);
        node_created = true;
    }


    /* A conditional node is constructed if its condition is true.  All
       the nodes that have been pushed since the node was opened are
       made children of the the conditional node, which is then pushed
       on to the stack.  If the condition is false the node is not
       constructed and they are left on the stack. */
    void closeNodeScope(Node n, boolean condition) {
        if (condition) {
            int a = nodeArity();
            mk = ((Integer)marks.pop()).intValue();
            while (a-- > 0) {
                Node c = popNode();
                c.jjtSetParent(n);
                n.jjtAddChild(c, a);
            }
            n.jjtClose();
            pushNode(n);
            node_created = true;
        } else {
            mk = ((Integer)marks.pop()).intValue();
            node_created = false;
        }
    }
}