package com.jclark.xsl.expr;

import com.jclark.xsl.om.*;

public class UnionNodeIterator implements NodeIterator {
  private NodeIterator iter1;
  private NodeIterator iter2;
  private Node node1;
  private Node node2;

  public UnionNodeIterator(NodeIterator iter1, NodeIterator iter2) throws XSLException {
    this.iter1 = iter1;
    this.iter2 = iter2;
    this.node1 = iter1.next();
    this.node2 = iter2.next();
  }

  public Node next() throws XSLException {
    if (node1 == null) {
      Node tem = node2;
      node2 = iter2.next();
      return tem;
    }
    if (node2 == null) {
      Node tem = node1;
      node1 = iter1.next();
      return tem;
    }
    int cmp = node1.compareTo(node2);
    if (cmp == 0) {
      Node tem = node1;
      node1 = iter1.next();
      node2 = iter2.next();
      return tem;
    }
    if (cmp < 0) {
      Node tem = node1;
      node1 = iter1.next();
      return tem;
    }
    else {
      Node tem = node2;
      node2 = iter2.next();
      return tem;
    }
  }
}