content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package mf.org.apache.xerces.impl.dtd.models;
  
  import mf.org.apache.xerces.impl.dtd.XMLContentSpec;
  
  /**
   * Content model Bin-Op node.
   *
   * @version $Id: CMBinOp.java 572057 2007-09-02 18:03:20Z mrglavas $
   * @xerces.internal
   */
  public class CMBinOp extends CMNode {
      // -------------------------------------------------------------------
      //  Private data members
      //
      //  fLeftChild
      //  fRightChild
      //      These are the references to the two nodes that are on either
      //      side of this binary operation.
      // -------------------------------------------------------------------
      private final CMNode fLeftChild;
      private final CMNode fRightChild;
  
      // -------------------------------------------------------------------
      //  Constructors
      // -------------------------------------------------------------------
      public CMBinOp(int type, CMNode leftNode, CMNode rightNode) {
          super(type);
  
          // Insure that its one of the types we require
          if ((type() != XMLContentSpec.CONTENTSPECNODE_CHOICE)
                  && (type() != XMLContentSpec.CONTENTSPECNODE_SEQ)) {
              throw new RuntimeException("ImplementationMessages.VAL_BST");
          }
  
          // Store the nodes and init any data that needs it
          fLeftChild = leftNode;
          fRightChild = rightNode;
      }
  
      // -------------------------------------------------------------------
      //  Package, final methods
      // -------------------------------------------------------------------
      final CMNode getLeft() {
          return fLeftChild;
      }
  
      final CMNode getRight() {
          return fRightChild;
      }
  
      // -------------------------------------------------------------------
      //  Package, inherited methods
      // -------------------------------------------------------------------
      @Override
      public boolean isNullable() {
          //
          //  If its an alternation, then if either child is nullable then
          //  this node is nullable. If its a concatenation, then both of
          //  them have to be nullable.
          //
          if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE)
              return (fLeftChild.isNullable() || fRightChild.isNullable());
          else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ)
              return (fLeftChild.isNullable() && fRightChild.isNullable());
          else
              throw new RuntimeException("ImplementationMessages.VAL_BST");
      }
  
      // -------------------------------------------------------------------
      //  Protected, inherited methods
      // -------------------------------------------------------------------
      @Override
      protected void calcFirstPos(CMStateSet toSet) {
          if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE) {
              // Its the the union of the first positions of our children.
              toSet.setTo(fLeftChild.firstPos());
              toSet.union(fRightChild.firstPos());
          } else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ) {
              //
              //  If our left child is nullable, then its the union of our
              //  children's first positions. Else is our left child's first
              //  positions.
              //
              toSet.setTo(fLeftChild.firstPos());
              if (fLeftChild.isNullable())
                  toSet.union(fRightChild.firstPos());
          } else {
              throw new RuntimeException("ImplementationMessages.VAL_BST");
          }
      }
  
      @Override
      protected void calcLastPos(CMStateSet toSet) {
          if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE) {
              // Its the the union of the first positions of our children.
              toSet.setTo(fLeftChild.lastPos());
              toSet.union(fRightChild.lastPos());
          } else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ) {
              //
              //  If our right child is nullable, then its the union of our
              //  children's last positions. Else is our right child's last
              //  positions.
              //
              toSet.setTo(fRightChild.lastPos());
              if (fRightChild.isNullable())
                  toSet.union(fLeftChild.lastPos());
          } else {
              throw new RuntimeException("ImplementationMessages.VAL_BST");
          }
      }
  }
  
  