package com.jclark.xsl.tr;

import com.jclark.xsl.om.*;
import com.jclark.xsl.expr.NodeSetExpr;
import com.jclark.xsl.expr.ExprContext;
import com.jclark.xsl.expr.NodeListSorter;

public class SortNodeSetExpr implements NodeSetExpr {
  private NodeSetExpr expr;
  private ComparatorTemplate comparatorTemplate;

  public SortNodeSetExpr(NodeSetExpr expr,
			 ComparatorTemplate comparatorTemplate) {
    this.expr = expr;
    this.comparatorTemplate = comparatorTemplate;
  }

  public NodeIterator eval(Node node, ExprContext context) throws XSLException {
    try {
      return NodeListSorter.sort(expr.eval(node, context),
				 comparatorTemplate.instantiate(node, context));
    }
    catch (UncheckedXSLException e) {
      throw e.getXSLException();
    }
  }

}