// Copyright (c) 2003  Per M.A. Bothner.// This is free software;  for terms and warranty disclaimer see ./COPYING.package gnu.kawa.xml;import gnu.lists.*;/** Used to implement a descendant:: step in a path expression. */public class DescendantAxis extends TreeScanner{  public static DescendantAxis make (NodePredicate type)  {    DescendantAxis axis = new DescendantAxis();    axis.type = type;    return axis;  }  public void scan (AbstractSequence seq, int ipos, PositionConsumer out)  {    if (! (seq instanceof TreeList))      { // AbstractSequence's nextMatching does not support descend.  FIXME.	ipos = seq.firstChildPos(ipos);	while (ipos != 0)	  {	    if (type.isInstancePos(seq, ipos))	      out.writePosition(seq, ipos);	    scan(seq, ipos, out);	    ipos = seq.nextPos(ipos);	  }	return;      }    int limit = seq.nextPos(ipos);    int child = ipos;    for (;;)      {	child = seq.nextMatching(child, type, limit, true);	if (child == 0)	  break;	out.writePosition(seq, child);      }  }}