/*
 * Copyright (c) 2004 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 3nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose,
 * including teaching and use in open-source projects.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book, 
 * please visit http://www.davidflanagan.com/javaexamples3.
 */
package je3.classes;

/**
 * This trivial subclass of AbstractTokenizer is suitable for tokenizing input
 * stored in a String, StringBuffer, CharBuffer, or any other class that 
 * implements CharSequence.  Because CharSequence instances may be mutable,
 * the construtor makes an internal copy of the character sequence.  This means
 * that any subsequent changes to the character sequence will not be seen
 * during tokenizing.
 *
 * @author David Flanagan
 */
public class CharSequenceTokenizer extends AbstractTokenizer {
    char[] buffer;  // a copy of the characters in the sequence

    /** 
     * Construct a new CharSequenceTokenizer to tokenize <tt>sequence</tt>.
     * This constructor makes an internal copy of the characters in the
     * specified sequence.
     * @param sequence the character sequence to be tokenized.
     */
    public CharSequenceTokenizer(CharSequence sequence) {
	buffer = sequence.toString().toCharArray();
    }

    /**
     * Set the inherited {@link #text} and {@link #numChars} fields.
     * This class knows the complete length of the input text, so it ignores
     * the <tt>bufferSize</tt> argument uses teh complete input sequence.
     * @param bufferSize ignored in this implementation
     */
    protected void createBuffer(int bufferSize) {
	assert text == null;       // verify that we're only called once
	text = buffer;
	numChars = buffer.length;
    }

    /**
     * Return false to indicate no more input is available.
     * {@link #createBuffer} fills the buffer with the complete input sequence,
     * so this method returns false to indicate that no more text is available.
     * @return always returns false.
     */
    protected boolean fillBuffer() { return false; }

    public static class Test {
	public static void main(String[] args) throws java.io.IOException {
	    StringBuffer text = new StringBuffer();
	    for(int i = 0; i < args.length; i++) text.append(args[i]+" ");
	    CharSequenceTokenizer t=new CharSequenceTokenizer(text.toString());
	    t.tokenizeWords(true).quotes("'&","';").skipSpaces(true);
	    while(t.next() != Tokenizer.EOF)
		System.out.println(t.tokenText());
	}
    }
}