Add the most useful Apache Commons utils

compiler/java/com/google/dart/compiler/util/apache/mutable/MutableInt.java

Index: compiler/java/com/google/dart/compiler/util/apache/mutable/MutableInt.java
diff --git a/compiler/java/com/google/dart/compiler/util/apache/mutable/MutableInt.java b/compiler/java/com/google/dart/compiler/util/apache/mutable/MutableInt.java
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+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.dart.compiler.util.apache.mutable;
+
+/**
+ * A mutable <code>int</code> wrapper.
+ * <p>
+ * Note that as MutableInt does not extend Integer, it is not treated by String.format as an Integer parameter. 
+ * <p>
+ * NOTICE: This file is modified copy of its original Apache library.
+ * It was moved to the different package, and changed to reduce number of dependencies.
+ * 
+ * @see Integer
+ * @since 2.1
+ * @version $Id: MutableInt.java 1160571 2011-08-23 07:36:08Z bayard $
+ */
+public class MutableInt extends Number implements Comparable<MutableInt>, Mutable<Number> {
+
+    /**
+     * Required for serialization support.
+     * 
+     * @see java.io.Serializable
+     */
+    private static final long serialVersionUID = 512176391864L;
+
+    /** The mutable value. */
+    private int value;
+
+    /**
+     * Constructs a new MutableInt with the default value of zero.
+     */
+    public MutableInt() {
+        super();
+    }
+
+    /**
+     * Constructs a new MutableInt with the specified value.
+     * 
+     * @param value  the initial value to store
+     */
+    public MutableInt(int value) {
+        super();
+        this.value = value;
+    }
+
+    /**
+     * Constructs a new MutableInt with the specified value.
+     * 
+     * @param value  the initial value to store, not null
+     * @throws NullPointerException if the object is null
+     */
+    public MutableInt(Number value) {
+        super();
+        this.value = value.intValue();
+    }
+
+    /**
+     * Constructs a new MutableInt parsing the given string.
+     * 
+     * @param value  the string to parse, not null
+     * @throws NumberFormatException if the string cannot be parsed into an int
+     * @since 2.5
+     */
+    public MutableInt(String value) throws NumberFormatException {
+        super();
+        this.value = Integer.parseInt(value);
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Gets the value as a Integer instance.
+     * 
+     * @return the value as a Integer, never null
+     */
+    public Integer getValue() {
+        return Integer.valueOf(this.value);
+    }
+
+    /**
+     * Sets the value.
+     * 
+     * @param value  the value to set
+     */
+    public void setValue(int value) {
+        this.value = value;
+    }
+
+    /**
+     * Sets the value from any Number instance.
+     * 
+     * @param value  the value to set, not null
+     * @throws NullPointerException if the object is null
+     */
+    public void setValue(Number value) {
+        this.value = value.intValue();
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Increments the value.
+     *
+     * @since Commons Lang 2.2
+     */
+    public void increment() {
+        value++;
+    }
+
+    /**
+     * Decrements the value.
+     *
+     * @since Commons Lang 2.2
+     */
+    public void decrement() {
+        value--;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Adds a value to the value of this instance.
+     * 
+     * @param operand  the value to add, not null
+     * @since Commons Lang 2.2
+     */
+    public void add(int operand) {
+        this.value += operand;
+    }
+
+    /**
+     * Adds a value to the value of this instance.
+     * 
+     * @param operand  the value to add, not null
+     * @throws NullPointerException if the object is null
+     * @since Commons Lang 2.2
+     */
+    public void add(Number operand) {
+        this.value += operand.intValue();
+    }
+
+    /**
+     * Subtracts a value from the value of this instance.
+     * 
+     * @param operand  the value to subtract, not null
+     * @since Commons Lang 2.2
+     */
+    public void subtract(int operand) {
+        this.value -= operand;
+    }
+
+    /**
+     * Subtracts a value from the value of this instance.
+     * 
+     * @param operand  the value to subtract, not null
+     * @throws NullPointerException if the object is null
+     * @since Commons Lang 2.2
+     */
+    public void subtract(Number operand) {
+        this.value -= operand.intValue();
+    }
+
+    //-----------------------------------------------------------------------
+    // shortValue and byteValue rely on Number implementation
+    /**
+     * Returns the value of this MutableInt as an int.
+     *
+     * @return the numeric value represented by this object after conversion to type int.
+     */
+    @Override
+    public int intValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a long.
+     *
+     * @return the numeric value represented by this object after conversion to type long.
+     */
+    @Override
+    public long longValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a float.
+     *
+     * @return the numeric value represented by this object after conversion to type float.
+     */
+    @Override
+    public float floatValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a double.
+     *
+     * @return the numeric value represented by this object after conversion to type double.
+     */
+    @Override
+    public double doubleValue() {
+        return value;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Gets this mutable as an instance of Integer.
+     *
+     * @return a Integer instance containing the value from this mutable, never null
+     */
+    public Integer toInteger() {
+        return Integer.valueOf(intValue());
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
+     * not <code>null</code> and is a <code>MutableInt</code> object that contains the same <code>int</code> value
+     * as this object.
+     * 
+     * @param obj  the object to compare with, null returns false
+     * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof MutableInt) {
+            return value == ((MutableInt) obj).intValue();
+        }
+        return false;
+    }
+
+    /**
+     * Returns a suitable hash code for this mutable.
+     * 
+     * @return a suitable hash code
+     */
+    @Override
+    public int hashCode() {
+        return value;
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Compares this mutable to another in ascending order.
+     * 
+     * @param other  the other mutable to compare to, not null
+     * @return negative if this is less, zero if equal, positive if greater
+     */
+    public int compareTo(MutableInt other) {
+        int anotherVal = other.value;
+        return value < anotherVal ? -1 : (value == anotherVal ? 0 : 1);
+    }
+
+    //-----------------------------------------------------------------------
+    /**
+     * Returns the String value of this mutable.
+     * 
+     * @return the mutable value as a string
+     */
+    @Override
+    public String toString() {
+        return String.valueOf(value);
+    }
+
+}