StringTokenizer.java

package client.net.sf.saxon.ce.tree.util;

/*
 *  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.
 */

/*
 * This file is based on code from the Apache Harmony Project.
 * http://svn.apache.org/repos/asf/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/StringTokenizer.java
 */

/**
 * This version of the class comes via the GWTx project and is modified to remove code not required by Saxon
 */


import java.util.Enumeration;
import java.util.NoSuchElementException;

/**
 * String tokenizer is used to break a string apart into tokens.
 *
 * If returnDelimiters is false, successive calls to nextToken() return maximal
 * blocks of characters that do not contain a delimiter.
 *
 * If returnDelimiters is true, delimiters are considered to be tokens, and
 * successive calls to nextToken() return either a one character delimiter, or a
 * maximal block of text between delimiters.
 */
public class StringTokenizer implements Enumeration<Object> {

    private String string;

    private String delimiters;

    private boolean returnDelimiters;

    private int position;

    /**
     * Constructs a new StringTokenizer for string using whitespace as the
     * delimiter, returnDelimiters is false.
     *
     * @param string
     *            the string to be tokenized
     */
    public StringTokenizer(String string) {
        this(string, " \t\n\r\f", false); //$NON-NLS-1$
    }

    /**
     * Constructs a new StringTokenizer for string using the specified
     * delimiters, returnDelimiters is false.
     *
     * @param string
     *            the string to be tokenized
     * @param delimiters
     *            the delimiters to use
     */
    public StringTokenizer(String string, String delimiters) {
        this(string, delimiters, false);
    }

    /**
     * Constructs a new StringTokenizer for string using the specified
     * delimiters and returning delimiters as tokens when specified.
     *
     * @param string
     *            the string to be tokenized
     * @param delimiters
     *            the delimiters to use
     * @param returnDelimiters
     *            true to return each delimiter as a token
     */
    public StringTokenizer(String string, String delimiters,
            boolean returnDelimiters) {
        if (string != null) {
            this.string = string;
            this.delimiters = delimiters;
            this.returnDelimiters = returnDelimiters;
            this.position = 0;
        } else
            throw new NullPointerException();
    }

    /**
     * Returns true if unprocessed tokens remain.
     *
     * @return true if unprocessed tokens remain
     */
    public boolean hasMoreElements() {
        return hasMoreTokens();
    }

    /**
     * Returns true if unprocessed tokens remain.
     *
     * @return true if unprocessed tokens remain
     */
    public boolean hasMoreTokens() {
        int length = string.length();
        if (position < length) {
            if (returnDelimiters)
                return true; // there is at least one character and even if
            // it is a delimiter it is a token

            // otherwise find a character which is not a delimiter
            for (int i = position; i < length; i++)
                if (delimiters.indexOf(string.charAt(i), 0) == -1)
                    return true;
        }
        return false;
    }

    /**
     * Returns the next token in the string as an Object.
     *
     * @return next token in the string as an Object
     * @exception NoSuchElementException
     *                if no tokens remain
     */
    public Object nextElement() {
        return nextToken();
    }

    /**
     * Returns the next token in the string as a String.
     *
     * @return next token in the string as a String
     * @exception NoSuchElementException
     *                if no tokens remain
     */
    public String nextToken() {
        int i = position;
        int length = string.length();

        if (i < length) {
            if (returnDelimiters) {
                if (delimiters.indexOf(string.charAt(position), 0) >= 0)
                    return String.valueOf(string.charAt(position++));
                for (position++; position < length; position++)
                    if (delimiters.indexOf(string.charAt(position), 0) >= 0)
                        return string.substring(i, position);
                return string.substring(i);
            }

            while (i < length && delimiters.indexOf(string.charAt(i), 0) >= 0)
                i++;
            position = i;
            if (i < length) {
                for (position++; position < length; position++)
                    if (delimiters.indexOf(string.charAt(position), 0) >= 0)
                        return string.substring(i, position);
                return string.substring(i);
            }
        }
        throw new NoSuchElementException();
    }

}

// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. 
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.