/* * Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package sun.tools.jstat;import java.util.*;/** * A typesafe enumeration for describing mathematical operators. * * @author Brian Doherty * @since 1.5 */public abstract class Operator { private static int nextOrdinal = 0; private static HashMap<String, Operator> map = new HashMap<String, Operator>(); private final String name; private final int ordinal = nextOrdinal++; private Operator(String name) { this.name = name; map.put(name, this); } protected abstract double eval(double x, double y); /* Operator '+' */ public static final Operator PLUS = new Operator("+") { protected double eval(double x, double y) { return x + y; } }; /* Operator '-' */ public static final Operator MINUS = new Operator("-") { protected double eval(double x, double y) { return x - y; } }; /* Operator '/' */ public static final Operator DIVIDE = new Operator("/") { protected double eval(double x, double y) { if (y == 0) { return Double.NaN; } return x / y; } }; /* Operator '*' */ public static final Operator MULTIPLY = new Operator("*") { protected double eval(double x, double y) { return x * y; } }; /** * Returns the string representation of this Operator object. * * @return the string representation of this Operator object */ public String toString() { return name; } /** * Maps a string to its corresponding Operator object. * * @param s an string to match against Operator objects. * @return The Operator object matching the given string. */ public static Operator toOperator(String s) { return map.get(s); } /** * Returns an enumeration of the keys for this enumerated type * * @param s an string to match against Operator objects. * @return The Operator object matching the given string. */ protected static Set keySet() { return map.keySet(); }}
/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.tools.jstat;
import java.util.*;
/**
* A typesafe enumeration for describing mathematical operators.
*
* @author Brian Doherty
* @since 1.5
*/
public abstract class Operator {
private static int nextOrdinal = 0;
private static HashMap<String, Operator> map = new HashMap<String, Operator>();
private final String name;
private final int ordinal = nextOrdinal++;
private Operator(String name) {
this.name = name;
map.put(name, this);
}
protected abstract double eval(double x, double y);
/* Operator '+' */
public static final Operator PLUS = new Operator("+") {
protected double eval(double x, double y) {
return x + y;
}
};
/* Operator '-' */
public static final Operator MINUS = new Operator("-") {
protected double eval(double x, double y) {
return x - y;
}
};
/* Operator '/' */
public static final Operator DIVIDE = new Operator("/") {
protected double eval(double x, double y) {
if (y == 0) {
return Double.NaN;
}
return x / y;
}
};
/* Operator '*' */
public static final Operator MULTIPLY = new Operator("*") {
protected double eval(double x, double y) {
return x * y;
}
};
/**
* Returns the string representation of this Operator object.
*
* @return the string representation of this Operator object
*/
public String toString() {
return name;
}
/**
* Maps a string to its corresponding Operator object.
*
* @param s an string to match against Operator objects.
* @return The Operator object matching the given string.
*/
public static Operator toOperator(String s) {
return map.get(s);
}
/**
* Returns an enumeration of the keys for this enumerated type
*
* @param s an string to match against Operator objects.
* @return The Operator object matching the given string.
*/
protected static Set keySet() {
return map.keySet();
}
}