package com.jclark.xsl.expr;

import com.jclark.xsl.om.*;

/**
 * Composition when expr1 is SINGLE_LEVEL and expr2 is STAYS_IN_SUBTREE.
 */

class SequenceComposeExpr extends ConvertibleNodeSetExpr {
  private final ConvertibleNodeSetExpr expr1;
  private final ConvertibleNodeSetExpr expr2;

  SequenceComposeExpr(ConvertibleNodeSetExpr expr1, ConvertibleNodeSetExpr expr2) {
    this.expr1 = expr1;
    this.expr2 = expr2;
  }

  public NodeIterator eval(Node node, ExprContext context) throws XSLException {
    return new SequenceComposeNodeIterator(expr1.eval(node, context),
					   expr2,
					   context);
  }

  int getOptimizeFlags() {
    // if expr2 is SINGLE_LEVEL then this will be too
    return expr2.getOptimizeFlags();
  }
}