1 /* ArithmeticExpr.java --
2 Copyright (C) 2004 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
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)
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.
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
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
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. */
38 package gnu.xml.xpath;
40 import javax.xml.namespace.QName;
41 import org.w3c.dom.Node;
44 * Binary arithmetic expression.
46 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
48 final class ArithmeticExpr
52 static final int ADD = 0;
53 static final int SUBTRACT = 1;
54 static final int MULTIPLY = 2;
55 static final int DIVIDE = 3;
56 static final int MODULO = 4;
62 ArithmeticExpr(Expr lhs, Expr rhs, int op)
76 throw new IllegalArgumentException();
80 public Object evaluate(Node context, int pos, int len)
82 Object left = lhs.evaluate(context, pos, len);
83 Object right = rhs.evaluate(context, pos, len);
85 double ln = _number(context, left);
86 double rn = _number(context, right);
90 return new Double(ln + rn);
92 return new Double(ln - rn);
94 return new Double(ln * rn);
96 if (rn == 0.0d || rn == -0.0d)
98 if (ln == 0.0d || ln == -0.0d)
100 return new Double(Double.NaN);
104 return new Double(ln < 0.0d ?
105 Double.NEGATIVE_INFINITY :
106 Double.POSITIVE_INFINITY);
109 return new Double(ln / rn);
111 if (rn == 0.0d || rn == 0.0d)
113 if (ln == 0.0d || ln == -0.0d)
115 return new Double(Double.NaN);
119 return new Double(ln < 0.0d ?
120 Double.NEGATIVE_INFINITY :
121 Double.POSITIVE_INFINITY);
124 return new Double(ln % rn);
126 throw new IllegalStateException();
130 public Expr clone(Object context)
132 return new ArithmeticExpr(lhs.clone(context), rhs.clone(context), op);
135 public boolean references(QName var)
137 return (lhs.references(var) || rhs.references(var));
140 public String toString()
142 StringBuffer buf = new StringBuffer();
165 return buf.toString();