/* Predicate.java -- 
   Copyright (C) 2004 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package gnu.xml.xpath;

import org.w3c.dom.Node;

/**
 * Tests whether an expression matches against a given context node.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
class Predicate
  extends Test
{

  final Expr expr;

  Predicate(Expr expr)
  {
    this.expr = expr;
  }

  public boolean matches(Node node, int pos, int len)
  {
    Object ret = expr.evaluate(node, pos, len);
    if (ret instanceof Double)
      {
        // Same as [position() = x]
        return ((Double) ret).intValue() == pos;
      }
    return Expr._boolean(node, expr.evaluate(node, pos, len));
  }

  public Test clone(Object context)
  {
    return new Predicate(expr.clone(context));
  }
  
  public String toString()
  {
    return "[" + expr + "]";
  }
  
}