import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
/**
 * Create a LocPathIterator object, including creation
 * of step walkers from the opcode list, and call back
 * into the Compiler to create predicate expressions.
 *
 * @param compiler The Compiler which is creating
 * this expression.
 * @param opPos The position of this iterator in the
 * opcode list from the compiler.
 *
 * @throws javax.xml.transform.TransformerException
 */
protected BasicTestIterator(Compiler compiler, int opPos, int analysis)
        throws javax.xml.transform.TransformerException
{
  super(compiler, opPos, analysis, false);

  int firstStepPos = OpMap.getFirstChildPos(opPos);
  int whatToShow = compiler.getWhatToShow(firstStepPos);

  if ((0 == (whatToShow
             & (DTMFilter.SHOW_ATTRIBUTE
             | DTMFilter.SHOW_NAMESPACE
             | DTMFilter.SHOW_ELEMENT
             | DTMFilter.SHOW_PROCESSING_INSTRUCTION)))
             || (whatToShow == DTMFilter.SHOW_ALL))
    initNodeTest(whatToShow);
  else
  {
    initNodeTest(whatToShow, compiler.getStepNS(firstStepPos),
                            compiler.getStepLocalName(firstStepPos));
  }
  initPredicateInfo(compiler, firstStepPos);
}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
/**
 * Create a OneStepIterator object.
 *
 * @param compiler A reference to the Compiler that contains the op map.
 * @param opPos The position within the op map, which contains the
 * location path expression for this itterator.
 *
 * @throws javax.xml.transform.TransformerException
 */
OneStepIterator(Compiler compiler, int opPos, int analysis)
        throws javax.xml.transform.TransformerException
{
  super(compiler, opPos, analysis);
  int firstStepPos = OpMap.getFirstChildPos(opPos);

  m_axis = WalkerFactory.getAxisFromStep(compiler, firstStepPos);

}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
static boolean functionProximateOrContainsProximate(Compiler compiler,
                                                    int opPos)
{
  int endFunc = opPos + compiler.getOp(opPos + 1) - 1;
  opPos = OpMap.getFirstChildPos(opPos);
  int funcID = compiler.getOp(opPos);
  //  System.out.println("funcID: "+funcID);
  //  System.out.println("opPos: "+opPos);
  //  System.out.println("endFunc: "+endFunc);
  switch(funcID)
  {
    case FunctionTable.FUNC_LAST:
    case FunctionTable.FUNC_POSITION:
      return true;
    default:
      opPos++;
      int i = 0;
      for (int p = opPos; p < endFunc; p = compiler.getNextOpPos(p), i++)
      {
        int innerExprOpPos = p+2;
        int argOp = compiler.getOp(innerExprOpPos);
        boolean prox = isProximateInnerExpr(compiler, innerExprOpPos);
        if(prox)
          return true;
      }

  }
  return false;
}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
static boolean isProximateInnerExpr(Compiler compiler, int opPos)
{
  int op = compiler.getOp(opPos);
  int innerExprOpPos = opPos+2;
  switch(op)
  {
    case OpCodes.OP_ARGUMENT:
      if(isProximateInnerExpr(compiler, innerExprOpPos))
        return true;
      break;
    case OpCodes.OP_VARIABLE:
    case OpCodes.OP_NUMBERLIT:
    case OpCodes.OP_LITERAL:
    case OpCodes.OP_LOCATIONPATH:
      break; // OK
    case OpCodes.OP_FUNCTION:
      boolean isProx = functionProximateOrContainsProximate(compiler, opPos);
      if(isProx)
        return true;
      break;
    case OpCodes.OP_GT:
    case OpCodes.OP_GTE:
    case OpCodes.OP_LT:
    case OpCodes.OP_LTE:
    case OpCodes.OP_EQUALS:
      int leftPos = OpMap.getFirstChildPos(op);
      int rightPos = compiler.getNextOpPos(leftPos);
      isProx = isProximateInnerExpr(compiler, leftPos);
      if(isProx)
        return true;
      isProx = isProximateInnerExpr(compiler, rightPos);
      if(isProx)
        return true;
      break;
    default:
      return true; // be conservative...
  }
  return false;
}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
/**
 * Create a OneStepIterator object.
 *
 * @param compiler A reference to the Compiler that contains the op map.
 * @param opPos The position within the op map, which contains the
 * location path expression for this itterator.
 *
 * @throws javax.xml.transform.TransformerException
 */
OneStepIteratorForward(Compiler compiler, int opPos, int analysis)
        throws javax.xml.transform.TransformerException
{
  super(compiler, opPos, analysis);
  int firstStepPos = OpMap.getFirstChildPos(opPos);

  m_axis = WalkerFactory.getAxisFromStep(compiler, firstStepPos);

}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
/**
 * Create a WalkingIterator iterator, including creation
 * of step walkers from the opcode list, and call back
 * into the Compiler to create predicate expressions.
 *
 * @param compiler The Compiler which is creating
 * this expression.
 * @param opPos The position of this iterator in the
 * opcode list from the compiler.
 * @param shouldLoadWalkers True if walkers should be
 * loaded, or false if this is a derived iterator and
 * it doesn't wish to load child walkers.
 *
 * @throws javax.xml.transform.TransformerException
 */
WalkingIterator(
        Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
          throws javax.xml.transform.TransformerException
{
  super(compiler, opPos, analysis, shouldLoadWalkers);

  int firstStepPos = OpMap.getFirstChildPos(opPos);

  if (shouldLoadWalkers)
  {
    m_firstWalker = WalkerFactory.loadWalkers(this, compiler, firstStepPos, 0);
    m_lastUsedWalker = m_firstWalker;
  }
}
 

import com.sun.org.apache.xpath.internal.compiler.OpMap; //导入依赖的package包/类
/**
 * Create a UnionPathIterator object, including creation
 * of location path iterators from the opcode list, and call back
 * into the Compiler to create predicate expressions.
 *
 * @param compiler The Compiler which is creating
 * this expression.
 * @param opPos The position of this iterator in the
 * opcode list from the compiler.
 *
 * @throws javax.xml.transform.TransformerException
 */
public UnionPathIterator(Compiler compiler, int opPos)
        throws javax.xml.transform.TransformerException
{

  super();

  opPos = OpMap.getFirstChildPos(opPos);

  loadLocationPaths(compiler, opPos, 0);
}