/* FileWordList.java */

import java.io.*;

/** Implements a class for reading a words (as Strings) from a file.
 */
public class FileWordList {

  /** Constructs a new FileWordList.
   * @param `fname' is the file name to be used for reading words.
   * @exception FileNotFoundException is thrown in the filename does
   *   does not exist.
   */
  public FileWordList( String fname ) throws FileNotFoundException {
    filename = fname;
    reset();
  }

  /** Re-opens the file for reading from the beginning.
   * @exception FileNotFoundException is thrown in the filename does
   *   does not exist.
   */
  public void reset() throws FileNotFoundException {
    FileInputStream f = new FileInputStream( filename );
    InputStreamReader i = new InputStreamReader( f );
    Reader r = new BufferedReader( i );

    fileStream = new StreamTokenizer( r );
  }

  /** Checks whether more input exists.
   * @return true <==> no more input waiting.
   */
  public boolean isEOF() {
    return (fileStream.ttype == StreamTokenizer.TT_EOF);
  }

  /** Read the next word from the file.
   * @return the next word from the file, or null if no more words 
   * are available.   
   */
  public String nextWord() throws IOException {
    if( isEOF() )
      return null;

    fileStream.nextToken();
    if( isEOF() )
      return null;

    return fileStream.sval;
  }

  private String          filename;
  private StreamTokenizer fileStream;
}