Source for gnu.xml.xpath.AndExpr

   1: /* AndExpr.java --
   2:    Copyright (C) 2004 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package gnu.xml.xpath;
  39: 
  40: import javax.xml.namespace.QName;
  41: import org.w3c.dom.Node;
  42: 
  43: /**
  44:  * Logical and.
  45:  *
  46:  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  47:  */
  48: public final class AndExpr
  49:   extends Expr
  50: {
  51: 
  52:   final Expr lhs;
  53:   final Expr rhs;
  54: 
  55:   public AndExpr(Expr lhs, Expr rhs)
  56:   {
  57:     this.lhs = lhs;
  58:     this.rhs = rhs;
  59:   }
  60: 
  61:   public Object evaluate(Node context, int pos, int len)
  62:   {
  63:     Object left = lhs.evaluate(context, pos, len);
  64:     if (!_boolean(context, left))
  65:       {
  66:         return Boolean.FALSE;
  67:       }
  68:     Object right = rhs.evaluate(context, pos, len);
  69:     return _boolean(context, right) ? Boolean.TRUE : Boolean.FALSE;
  70:   }
  71: 
  72:   public Expr clone(Object context)
  73:   {
  74:     return new AndExpr(lhs.clone(context), rhs.clone(context));
  75:   }
  76: 
  77:   public boolean references(QName var)
  78:   {
  79:     return (lhs.references(var) || rhs.references(var));
  80:   }
  81: 
  82:   public String toString()
  83:   {
  84:     return lhs + " and " + rhs;
  85:   }
  86: 
  87: }