package com.jclark.xsl.expr;

import com.jclark.xsl.om.*;

/**
 * descendants-or-self(node())/E when E has STAYS_IN_SUBTREE
 */

class SubtreeExpr extends ConvertibleNodeSetExpr {
  private final ConvertibleNodeSetExpr expr;

  SubtreeExpr(ConvertibleNodeSetExpr expr) {
    this.expr = expr;
  }

  public NodeIterator eval(Node node, ExprContext context) throws XSLException {
    return new UnionNodeIterator(expr.eval(node, context),
				 new SequenceComposeNodeIterator(node.getChildren(),
								 this,
								 context));
  }

  int getOptimizeFlags() {
    // if expr is SINGLE_LEVEL then this will be too
    return expr.getOptimizeFlags();
  }
}