package com.jclark.xsl.expr;

import com.jclark.xsl.om.*;

class CountFunction extends Function1 {
  ConvertibleExpr makeCallExpr(ConvertibleExpr e) throws ParseException {
    final NodeSetExpr nse = e.makeNodeSetExpr();
    return new ConvertibleNumberExpr() {
      public double eval(Node node, ExprContext context) throws XSLException {
	return count(nse.eval(node, context));
      }
    };
  }

  static private final int count(NodeIterator iter) throws XSLException {
    int n = 0;
    while (iter.next() != null)
	n++;
    return n;
  }
}