import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import java.lang.reflect.*;
import java.net.*;
import java.io.*;
import javax.swing.*;
import java.util.regex.*;
import java.util.*;
public class main {
  public static void main(String[] args) throws Exception {
    String s = loadMainJava();

List<String> tok = JavaTok.split(s);

for (int i = 1; i+2 < tok.size(); i += 2)
  if (tok.get(i).equals("case")
    && !tok.get(i+2).startsWith("'"))
    tok.set(i, "_case");
    
s = JavaTok.join(tok);
    saveMainJava(s);
  }

  static String loadMainJava() throws IOException {
    return loadTextFile("input/main.java", "");
  }

  static void saveMainJava(String s) throws IOException {
    saveTextFile("output/main.java", s);
  }

  /** writes safely (to temp file, then rename) */
  public static void saveTextFile(String fileName, String contents) throws IOException {
    File file = new File(fileName);
    File parentFile = file.getParentFile();
    if (parentFile != null)
      parentFile.mkdirs();
    String tempFileName = fileName + "_temp";
    FileOutputStream fileOutputStream = new FileOutputStream(tempFileName);
    OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "UTF-8");
    PrintWriter printWriter = new PrintWriter(outputStreamWriter);
    printWriter.print(contents);
    printWriter.close();
    if (file.exists() && !file.delete())
      throw new IOException("Can't delete " + fileName);

    if (!new File(tempFileName).renameTo(file))
      throw new IOException("Can't rename " + tempFileName + " to " + fileName);
  }

  public static String loadTextFile(String fileName, String defaultContents) throws IOException {
    if (!new File(fileName).exists())
      return defaultContents;

    FileInputStream fileInputStream = new FileInputStream(fileName);
    InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "UTF-8");
    return loadTextFile(inputStreamReader);
  }

  public static String loadTextFile(Reader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    try {
      BufferedReader bufferedReader = new BufferedReader(reader);
      String line;
      while ((line = bufferedReader.readLine()) != null)
        builder.append(line).append('\n');
    } finally {
      reader.close();
    }
    return builder.length() == 0 ? "" : builder.substring(0, builder.length()-1);
  }
}

class JavaTok {
  static String join(List<String> cnc) {
    StringBuilder buf = new StringBuilder();
    for (String s : cnc) buf.append(s);
    return buf.toString();
  }
  
  static List<String> split(String src) {
    Java20 lex = new Java20();
    src = src.replace("\r\n", "\n");
    LineNumberReader source = new LineNumberReader(new StringReader(src));
    int lineNr = source.getLineNumber()+1;
    List<T> list = new ArrayList<T>();
    try {
      for (Object a; (a = lex.grab(source)) != lex.$;) {
        String word = lex.word();
        String q = quote(word);
        //System.out.println("grabbed at line " + lineNr + ": " + a + " " + q);
        lineNr = source.getLineNumber()+1;
        
        T t = new T(a, word);
        boolean isSpace = t.isSpace();
        if (isSpace && list.size() > 0 && list.get(list.size()-1).isSpace())
          list.get(list.size()-1).word += word; // merge spaces
        else
          list.add(t);
      }
    } catch (Lexicon.Exception e) {
      throw new RuntimeException(e);
    }
    
    List<String> cnc = new ArrayList<String>();
    for (int i = 0; i < list.size(); ) {
      T t = list.get(i);
      boolean shouldBeSpace = (cnc.size() % 2) == 0;
      boolean isSpace = t.isSpace();
      if (shouldBeSpace == isSpace) {
        cnc.add(t.word);
        ++i;
      } else if (shouldBeSpace)
        cnc.add("");
      else {
        System.out.println(cncToLines(cnc));
        throw new RuntimeException("TILT at " + cnc.size() + ": " + quote(t.word));
      }
    }
    if ((cnc.size() % 2) == 0)
      cnc.add("");

    return cnc;
  }
  
  static class T {
    Object a; String word;
    
    T(Object a, String word) { this.a = a; this.word = word; }
    
    boolean isSpace() {
      return a.equals("WHITE_SPACE") || a.equals("COMMENT");
    }
  }
  
  static String cncToLines(List<String> cnc) {
    StringBuilder out = new StringBuilder();
    for (String token : cnc)
      out.append(quote(token) + "\n");
    return out.toString();
  }
  
  public static String quote(String s) {
    if (s == null) return "null";
    return "\"" + s.replace("\\", "\\\\").replace("\"", "\\\"").replace("\r", "\\r").replace("\n", "\\n") + "\"";
  }
  
  static class Java20 extends Lexicon {

	Java20() {

		/**
		* Grammar for Java 2.0.
		*
		* Nonterminal - first letter uppercase
		* TERMINAL - all letters uppercase
		* keyword - all letters lowercase
		*/
		int INFINITY = -1;

		/**
		* 19.3 Terminals from section 3.6: White Space: [[:space:]]
		*/
		put("WHITE_SPACE", new Repetition(PosixClass.space(), 1, INFINITY));

		/**
		* 19.3 Terminals from section 3.7: Comment
		*/
		put("COMMENT", new Union(

			//
			// Traditional Comment: /\*[^*]+(\*([^*/][^*]*)?)*\*/
			//
			new Concatenation(
				new Singleton("/*"), new Concatenation(
				new Repetition(new NonMatch("*"), 1, INFINITY), new Concatenation(
				new Repetition(
					new Concatenation(
						new Singleton("*"),
						new Repetition(new Concatenation(
							new NonMatch("*/"),
							new Repetition(new NonMatch("*"), 0, INFINITY)
						), 0, 1)
					), 0, INFINITY
				),
				new Singleton("*/")
			))), new Union(

			/**
			* End Of Line Comment: //[^\n]*\n
			*/
			new Concatenation(
				new Singleton("//"), new Concatenation(
				new Repetition(new NonMatch("\n"), 0, INFINITY),
				new Singleton("\n")
			)),

			//
			// Documentation Comment: /\*\*(([^*/][^*]*)?\*)*/
			//
			new Concatenation(
				new Singleton("/**"), new Concatenation(
				new Repetition(
					new Concatenation(
						new Repetition(new Concatenation(
							new NonMatch("*/"),
							new Repetition(new NonMatch("*"), 0, INFINITY)
						), 0, 1),
						new Singleton("*")
					), 0, INFINITY
				),
				new Singleton("/")
			))
		)));

		put("IDENTIFIER", new Concatenation(
			new Union(
				PosixClass.alpha(),
				new Match("_$")
			),
			new Repetition(
				new Union(
					PosixClass.alnum(),
					new Match("_$")
				), 0, INFINITY
			)
		));

		/**
		* 19.3 Terminals from section 3.9: Keyword (recognized but not in the Java grammar)
		*/
		put("KEYWORD", new Union(
			new Singleton("const"),
			new Singleton("goto")
		));

		/**
		* 19.3 Terminals from section 3.10.1: Integer Literal
		*/
		put("INTEGER_LITERAL", new Concatenation(
			new Union(
				/**
				* Decimal Integer Literal: 0|[1-9][[:digit:]]*
				*/
				new Singleton("0"), new Union(

				new Concatenation(
					new Range('1', '9'),
					new Repetition(PosixClass.digit(), 0, INFINITY)
				), new Union(

				/**
				* Hexadecimal Integer Literal: 0[xX][[:xdigit:]]+
				*/
				new Concatenation(
					new Singleton("0"), new Concatenation(
					new Match("xX"),
					new Repetition(PosixClass.xdigit(), 1, INFINITY)
				)),

				/**
				* Octal Integer Literal: 0[0-7]+
				*/
				new Concatenation(
					new Singleton("0"),
					new Repetition(new Range('0', '7'), 1, INFINITY)
				)
			))),
			new Repetition(new Match("lL"), 0, 1)
		));

		/**
		* 19.3 Terminals from section 3.10.2: Floating-Point Literal
		*/
		put("FLOATING_POINT_LITERAL", new Union(

			/**
			* [[:digit:]]+\.[[:digit:]]*([eE][-+]?[[:digit:]]+)?[fFdD]?
			*/
			new Concatenation(
				new Repetition(PosixClass.digit(), 1, INFINITY), new Concatenation(
				new Singleton("."), new Concatenation(
				new Repetition(PosixClass.digit(), 0, INFINITY), new Concatenation(
				new Repetition(new Concatenation(
					new Match("eE"), new Concatenation(
					new Repetition(new Match("-+"), 0, 1),
					new Repetition(PosixClass.digit(), 1, INFINITY)
				)), 0, 1),
				new Repetition(new Match("fFdD"), 0, 1)
			)))), new Union(

			/**
			* \.[[:digit:]]+([eE][-+]?[[:digit:]]+)?[fFdD]?
			*/
			new Concatenation(
				new Singleton("."), new Concatenation(
				new Repetition(PosixClass.digit(), 1, INFINITY), new Concatenation(
				new Repetition(new Concatenation(
					new Match("eE"), new Concatenation(
					new Repetition(new Match("-+"), 0, 1),
					new Repetition(PosixClass.digit(), 1, INFINITY)
				)), 0, 1),
				new Repetition(new Match("fFdD"), 0, 1)
			))), new Union(

			/**
			* [[:digit:]]+[eE][-+]?[[:digit:]]+[fFdD]?
			*/
			new Concatenation(
				new Repetition(PosixClass.digit(), 1, INFINITY), new Concatenation(
				new Match("eE"), new Concatenation(
				new Repetition(new Match("-+"), 0, 1), new Concatenation(
				new Repetition(PosixClass.digit(), 1, INFINITY),
				new Repetition(new Match("fFdD"), 0, 1)
			)))),

			/**
			* [[:digit:]]+([eE][-+]?[[:digit:]]+)?[fFdD]
			*/
			new Concatenation(
				new Repetition(PosixClass.digit(), 1, INFINITY), new Concatenation(
				new Repetition(new Concatenation(
					new Match("eE"), new Concatenation(
					new Repetition(new Match("-+"), 0, 1),
					new Repetition(PosixClass.digit(), 1, INFINITY)
				)), 0, 1),
				new Match("fFdD")
			))
		))));

		/**
		* 19.3 Terminals from section 3.10.3: Boolean Literal
		*/
		put("BOOLEAN_LITERAL", new Union(
			new Singleton("true"),
			new Singleton("false")
		));

		/**
		* 19.3 Terminals from section 3.10.4: Character Literal
		*/
		put("CHARACTER_LITERAL", new Concatenation(
			new Singleton("'"), new Concatenation(
			new Union(

				/**
				* Single Character: [^\r\n'\\]
				*/
				new NonMatch("\r\n'\\"),

				/**
				* Escape Sequence: \\([btnfr\"'\\]|[0-3]?[0-7]{1,2})
				*/
				new Concatenation(
					new Singleton("\\"),
					new Union(
						new Match("btnfr\"'\\"),
						new Concatenation(
							new Repetition(new Range('0', '3'), 0, 1),
							new Repetition(new Range('0', '7'), 1, 2)
						)
					)
				)
			),
			new Singleton("'")
		)));

		put("MULTILINE_LITERAL", new Concatenation(
			new Singleton("[["), new Concatenation(
			new Repetition(
				new Union(
					new NonMatch("]"),
					new Concatenation(
					  new Singleton("]"), new NonMatch("]"))
			  ), 0, INFINITY
			),
			new Singleton("]]")
		)));

		/**
		* 19.3 Terminals from section 3.10.5: String Literal
		*/
		put("STRING_LITERAL", new Concatenation(
			new Singleton("\""), new Concatenation(
			new Repetition(
				new Union(

					/**
					* Single Character: [^\r\n"\\]
					*/
					new NonMatch("\r\n\"\\"),

					/**
					* Escape Sequence: \\([btnfr\"'\\]|[0-3]?[0-7]{1,2})
					*/
					new Concatenation(
						new Singleton("\\"),
						new Union(
							new Match("btnfr\"'\\"),
							new Union(
  							new Concatenation(
  								new Repetition(new Range('0', '3'), 0, 1),
  								new Repetition(new Range('0', '7'), 1, 2)
  							),
  							new Concatenation(
  							  new Singleton("u"),
  							  new Repetition(new Match("0123456789abcdefABCDEF"), 4, 4)
  							)
  						)
						)
					)
				), 0, INFINITY
			),
			new Singleton("\"")
		)));

		/**
		* 19.3 Terminals section 3.10.7: Null Literal
		*/
		put("NULL_LITERAL", new Singleton("null"));
		
		// OK, it seems we have to add some more stuff...
		
		//put("OTHER1", new Match(";{}=,<>[]().+-:|&!"));
		//put("OTHER1", new NonMatch("")); // catch anything, one character at a time
		put("OTHER1", new NonMatch(" \t\r\n")); // catch any non-whitespace, one character at a time

	}
} // class Java20
}
/**
* <p>This class implements a {@link Lexicon}.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
class Lexicon {
//Q
/**
* <p>The number of lexical NFA states constructed.</p>
*/
private static int QSize = 0;

/**
* <p>Creates a new state in the lexical NFA.</p>
*
* @return a new state in the lexical NFA.
*/
private static Integer s() {
	return ++QSize;
}
//delta
/**
* <p>The transition relation of the lexical NFA.</p>
*/
private static final Stack<Stack<Object>> delta = new Stack<Stack<Object>>();

/**
* <p>Puts a transition into the lexical NFA.</p>
*
* @param s the state from which the transition is made.
* @param A the <code>Alphabet</code> on which the transition is made.
* @param r the state to which the transition is made.
*/
private static void put(Integer s, Alphabet A, Integer r) {

	if (Math.max(s,r) >= delta.size()) delta.setSize(Math.max(s,r)+1);

	Stack<Object> pairs = delta.get(s);
	if (pairs == null) delta.set(s, pairs = new Stack<Object>());

	pairs.push(A);
	pairs.push(r);
}
//Set
/**
* <p>This class implements a {@link Lexicon.Set <code>Set</code>}.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
* @param <E> the element type.
*/
static class Set<E> extends Stack<E> {

	/**
	* <p>The null exclusion indicator. If <code>true</code>, <code>add</code> methods will not add <code>null</code> to this <code>Set</code>.</p>
	*/
	private final boolean excludeNull;

	/**
	* <p>Constructs a <code>Set</code> with an initial capacity.</p>
	*
	* @param capacity the initial capacity. The magnitude of <code>capacity</code> is the initial capacity. The null exclusion indicator is initialized to <code>true</code> if <code>capacity</code> is negative.
	*/
	Set(int capacity) {
		super();
		ensureCapacity(Math.abs(capacity));
		excludeNull = (capacity < 0);
	}

	/**
	* <p>Adds an element to this <code>Set</code>. The element is not added if it occurs in this <code>Set</code> or it is <code>null</code> and the null exclusion indicator is <code>true</code>. The capacity is expanded if necessary.</p>
	*
	* @param element the element to add to this <code>Set</code>.
	* @return <code>true</code> if this <code>Set</code> is changed; <code>false</code> otherwise.
	*/
	public boolean add(E element) {
		if (excludeNull && element == null || contains(element)) return false;
		push(element);
		return true;
	}

	/**
	* <p>Adds a <code>Set</code> of elements to this <code>Set</code>. An element is not added if it occurs in this <code>Set</code> or it is <code>null</code> and the null exclusion indicator is <code>true</code>. The capacity is expanded if necessary.</p>
	*
	* @param index the index in <code>S</code> beyond which elements are added.
	* @param S the <code>Set</code> to add to this <code>Set</code>.
	* @return <code>true</code> if this <code>Set</code> is changed; <code>false</code> otherwise.
	*/
	boolean add(int index, Set<E> S) {
		if (S == null) return false;
		boolean push = isEmpty();
		boolean add = false;

		for (int i = index; i < S.size(); i++) {
			E element = S.get(i);

			if (!(excludeNull && element == null))
				if (push) {
					push(element);
					add = true;
				}
				else if (add(element))
					add = true;
		}
		return add;
	}

	/**
	* <p>Adds a <code>Set</code> of elements to this <code>Set</code>. An element is not added if it occurs in this <code>Set</code> or it is <code>null</code> and the null exclusion indicator is <code>true</code>. The capacity is expanded if necessary.</p>
	*
	* @param S the <code>Set</code> to add to this <code>Set</code>.
	* @return <code>true</code> if this <code>Set</code> is changed; <code>false</code> otherwise.
	*/
	boolean add(Set<E> S) {
		return add(0, S);
	}

	public String toString() {
		StringBuffer result = new StringBuffer(80);
		result.append('{');

		for (int i = 0; i < size(); i++) {
			if (i > 0) result.append(' ');
			result.append(get(i));
		}
		result.append('}');
		return result.toString();
	}
//Set
}
//I
/**
* <p>The initial states of the lexical NFA. When empty, there is a need to compute the current initial states. It is computed only on demand created by {@link #initial()}.</p>
*/
private final Set<Integer> I;
//F
/**
* <p>The final states of the lexical NFA. A final state is mapped to the terminal it accepts in this <code>Lexicon</code>. When empty, there is a need to compute current final states. It is computed only on demand created by {@link #initial()}.</p>
*/
private final Map<Integer, Object> F;
//Lexicon.transition
/**
* <p>Computes a transition using the lexical NFA.</p>
*
* @param S the states from which the transition is made.
* @param a the character on which the transition is made.
* @param R the states to which the transition is made.
* @return the states to which the transition is made.
*/
private static Set<Integer> transition(Set<Integer> S, char a, Set<Integer> R) {
	R.clear();

	for (Integer s : S) {
		Stack<Object> pairs = delta.get(s);

		if (pairs != null)
			for (int k = 0; k < pairs.size(); k += 2) {
				Alphabet A = (Alphabet)pairs.get(k);

				if (A != null) {
					Integer r = (Integer)pairs.get(k+1);
					if (A.contains(a)) R.add(r);
				}
			}
	}
	return R;
}
//Lexicon.closure
/**
* <p>Computes a reflexive transitive closure under empty transition using the lexical NFA. The closure is computed in place by a breadth-first search expanding <code>S</code>.</p>
*
* @param S the states whose reflexive transitive closure is computed under empty transition.
* @return the reflexive transitive closure of <code>S</code> under empty transition.
*/
private static Set<Integer> closure(Set<Integer> S) {

	for (int i = 0; i < S.size(); i++) {
		Integer s = S.get(i);
		Stack<Object> pairs = delta.get(s);

		if (pairs != null)
			for (int k = 0; k < pairs.size(); k += 2) {
				Alphabet A = (Alphabet)pairs.get(k);

				if (A == null) {
					Integer r = (Integer)pairs.get(k+1);
					S.add(r);
				}
			}
	}
	return S;
}
//Expression
/**
* <p>This class implements an {@link Lexicon.Expression <code>Expression</code>} expressing a regular language.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
abstract public static class Expression implements Cloneable {

	/**
	* <p>The initial state of the NFA constructed from this <code>Expression</code>.</p>
	*/
	Integer i;
	/**
	* <p>The final state of the NFA constructed from this <code>Expression</code>.</p>
	*/
	Integer f;

	/**
	* <p>Creates a clone of this <code>Expression</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Expression</code>.
	*/
	abstract public Object clone();
}
//Alphabet
/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} of character symbols.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
abstract public static class Alphabet extends Expression {

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	abstract boolean contains(char a);
}
//Match
/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} containing some characters.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Match extends Alphabet {

	/**
	* <p>The {@link Character} or {@link String} representing this <code>Alphabet</code>.</p>
	*/
	final Object A;

	/**
	* <p>Constructs an <code>Alphabet</code> containing some characters, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param i the initial state of the NFA constructed.
	* @param A the {@link Character} or {@link String} of characters in this <code>Alphabet</code>.
	* @param f the final state of the NFA constructed.
	*/
	private Match(Integer i, Object A, Integer f) {
		this.A = A;
		put(this.i = i, this, this.f = f);
	}

	/**
	* <p>Constructs an <code>Alphabet</code> containing one character, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param i the initial state of the NFA constructed.
	* @param a the character in this <code>Alphabet</code>.
	* @param f the final state of the NFA constructed.
	*/
	private Match(Integer i, char a, Integer f) {
		this(i, new Character(a), f);
	}

	/**
	* <p>Constructs an <code>Alphabet</code> containing one character, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param a the character in this <code>Alphabet</code>.
	*/
	public Match(char a) {
		this(s(), a, s());
	}

	/**
	* <p>Constructs an <code>Alphabet</code> containing some characters, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param A the {@link Character} or {@link String} of characters in this <code>Alphabet</code>.
	*/
	public Match(Object A) {
		this(s(), A, s());
	}

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	boolean contains(char a) {
		if (A instanceof Character)
			return (Character)A == a;

		if (A instanceof String)
			return ((String)A).indexOf(a) != -1;

		if (A instanceof Stack<?>)
			for (Alphabet alphabet : (Stack<Alphabet>)A)
				if (alphabet.contains(a)) return true;
		return false;
	}

	/**
	* <p>Creates a clone of this <code>Alphabet</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Alphabet</code>.
	*/
	public Object clone() {
		return new Match(A);
	}
}
//NonMatch
/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} containing all except some characters.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class NonMatch extends Match {

	/**
	* <p>Constructs an <code>Alphabet</code> containing all characters except one, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param a the character not in this <code>Alphabet</code>.
	*/
	public NonMatch(char a) {
		super(a);
	}

	/**
	* <p>Constructs an <code>Alphabet</code> containing all characters except some, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param A the {@link Character} or {@link String} of characters not in this <code>Alphabet</code>.
	*/
	public NonMatch(Object A) {
		super(A);
	}

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	boolean contains(char a) {
		return a != (char)-1 && !super.contains(a);
	}

	/**
	* <p>Creates a clone of this <code>Alphabet</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Alphabet</code>.
	*/
	public Object clone() {
		return new NonMatch(A);
	}
}
//Range
/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} containing the characters in a range.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Range extends Alphabet {

	/**
	* <p>The first character in the range.</p>
	*/
	private final char a1;
	/**
	* <p>The last character in the range.</p>
	*/
	private final char a2;

	/**
	* <p>Constructs an <code>Alphabet</code> containing the characters in a range, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param a1 the first character in the range.
	* @param a2 the last character in the range.
	*/
	public Range(char a1, char a2) {
		this.a1 = a1;
		this.a2 = a2;
		put(i = s(), this, f = s());
	}

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	boolean contains(char a) {
		return a1 <= a && a <= a2;
	}

	/**
	* <p>Creates a clone of this <code>Alphabet</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Alphabet</code>.
	*/
	public Object clone() {
		return new Range(a1, a2);
	}
}

/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} containing the characters in a POSIX character class.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class PosixClass extends Alphabet {

	/**
	* <p>The bit mask representing this <code>PosixClass</code>.</p>
	*/
	private final int posixClass;

	/**
	* <p>Constructs an <code>Alphabet</code> containing the characters in a POSIX character class, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param posixClass the bit mask representing this <code>PosixClass</code>.
	*/
	private PosixClass(int posixClass) {
		this.posixClass = posixClass;
		put(i = s(), this, f = s());
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the uppercase alphabetic characters.</p>
	*
	* @return an <code>Alphabet</code> containing the uppercase alphabetic characters.
	*/
	public static PosixClass upper() {
		return new PosixClass(0x0001);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the lowercase alphabetic characters.</p>
	*
	* @return an <code>Alphabet</code> containing the lowercase alphabetic characters.
	*/
	public static PosixClass lower() {
		return new PosixClass(0x0002);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the alphabetic characters.</p>
	*
	* @return an <code>Alphabet</code> containing the alphabetic characters.
	*/
	public static PosixClass alpha() {
		return new PosixClass(0x0004);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the decimal digit characters.</p>
	*
	* @return an <code>Alphabet</code> containing the decimal digit characters.
	*/
	public static PosixClass digit() {
		return new PosixClass(0x0008);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the hexadecimal digit characters.</p>
	*
	* @return an <code>Alphabet</code> containing the hexadecimal digit characters.
	*/
	public static PosixClass xdigit() {
		return new PosixClass(0x0010);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the alphanumeric characters.</p>
	*
	* @return an <code>Alphabet</code> containing the alphanumeric characters.
	*/
	public static PosixClass alnum() {
		return new PosixClass(0x0020);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the punctuation characters.</p>
	*
	* @return an <code>Alphabet</code> containing the punctuation characters.
	*/
	public static PosixClass punct() {
		return new PosixClass(0x0040);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the graphical characters.</p>
	*
	* @return an <code>Alphabet</code> containing the graphical characters.
	*/
	public static PosixClass graph() {
		return new PosixClass(0x0080);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the printable characters.</p>
	*
	* @return an <code>Alphabet</code> containing the printable characters.
	*/
	public static PosixClass print() {
		return new PosixClass(0x0100);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the blank characters.</p>
	*
	* @return an <code>Alphabet</code> containing the blank characters.
	*/
	public static PosixClass blank() {
		return new PosixClass(0x0200);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the space characters.</p>
	*
	* @return an <code>Alphabet</code> containing the space characters.
	*/
	public static PosixClass space() {
		return new PosixClass(0x0400);
	}

	/**
	* <p>Creates an <code>Alphabet</code> containing the control characters.</p>
	*
	* @return an <code>Alphabet</code> containing the control characters.
	*/
	public static PosixClass cntrl() {
		return new PosixClass(0x0800);
	}

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	boolean contains(char a) {
		int UPPER = 0x0001; int LOWER = 0x0002;
		int ALPHA = 0x0004; int DIGIT = 0x0008;
		int XDIGIT = 0x0010; int ALNUM = 0x0020;
		int PUNCT = 0x0040; int GRAPH = 0x0080;
		int PRINT = 0x0100; int BLANK = 0x0200;
		int SPACE = 0x0400; int CNTRL = 0x0800;
		int classes = 0;

		switch (Character.getType(a)) {
			default: break;
			case Character.UPPERCASE_LETTER:
				classes |= UPPER | ALPHA | (('A' <= a && a <= 'F') ? XDIGIT : 0) | ALNUM | GRAPH | PRINT; break;
			case Character.LOWERCASE_LETTER:
				classes |= LOWER | ALPHA | (('a' <= a && a <= 'f') ? XDIGIT : 0) | ALNUM | GRAPH | PRINT; break;
			case Character.TITLECASE_LETTER:
			case Character.MODIFIER_LETTER:
			case Character.OTHER_LETTER:
				classes |= ALPHA | ALNUM | GRAPH | PRINT; break;
			case Character.NON_SPACING_MARK:
			case Character.COMBINING_SPACING_MARK:
			case Character.ENCLOSING_MARK:
				classes |= PUNCT | GRAPH | PRINT; break;
			case Character.DECIMAL_DIGIT_NUMBER:
				classes |= DIGIT | XDIGIT | ALNUM | GRAPH | PRINT; break;
			case Character.LETTER_NUMBER:
			case Character.OTHER_NUMBER:
				classes |= ALNUM | GRAPH | PRINT; break;
			case Character.CONNECTOR_PUNCTUATION:
			case Character.DASH_PUNCTUATION:
			case Character.START_PUNCTUATION:
			case Character.END_PUNCTUATION:
			case Character.INITIAL_QUOTE_PUNCTUATION:
			case Character.FINAL_QUOTE_PUNCTUATION:
			case Character.OTHER_PUNCTUATION:
			case Character.MATH_SYMBOL:
			case Character.CURRENCY_SYMBOL:
			case Character.MODIFIER_SYMBOL:
			case Character.OTHER_SYMBOL:
				classes |= PUNCT | GRAPH | PRINT; break;
			case Character.SPACE_SEPARATOR:
				classes |= PRINT | BLANK | SPACE; break;
			case Character.LINE_SEPARATOR:
			case Character.PARAGRAPH_SEPARATOR:
				break;
			case Character.CONTROL:
				classes |= ((a == '\t') ? BLANK : 0) | ((a == '\t' || a == '\n' || a == '\013' || a == '\f' || a == '\r') ? SPACE : 0) | CNTRL; break;
			case Character.FORMAT:
			case Character.SURROGATE:
			case Character.PRIVATE_USE:
			case Character.UNASSIGNED:
				break;
		}
		return (classes & posixClass) != 0;
	}

	/**
	* <p>Creates a clone of this <code>Alphabet</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Alphabet</code>.
	*/
	public Object clone() {
		return new PosixClass(posixClass);
	}
}
//UnicodeCategory
/**
* <p>This class implements an {@link Lexicon.Alphabet <code>Alphabet</code>} containing the characters in a Unicode general category.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class UnicodeCategory extends Alphabet {

	/**
	* <p>The byte representing the Unicode general category.</p>
	*/
	private final byte category;

	/**
	* <p>Constructs an <code>Alphabet</code> containing the characters in a Unicode general category, and builds the NFA constructed from this <code>Expression</code>. The class {@link Character} defines byte constants representing each of the Unicode general categories.</p>
	*
	* @param category The byte representing the Unicode general category.
	* @see Character
	*/
	public UnicodeCategory(byte category) {
		this.category = category;
		put(i = s(), this, f = s());
	}

	/**
	* <p>Indicates whether a character occurs in this <code>Alphabet</code>.</p>
	*
	* @param a the character whose status is requested.
	* @return <code>true</code> if <code>a</code> occurs in this <code>Alphabet</code>; <code>false</code> otherwise.
	*/
	boolean contains(char a) {
		return Character.getType(a) == category;
	}

	/**
	* <p>Creates a clone of this <code>Alphabet</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Alphabet</code>.
	*/
	public Object clone() {
		return new UnicodeCategory(category);
	}
}
//Repetition
/**
* <p>This class implements an {@link Lexicon.Expression <code>Expression</code>} expressing the repetition of a regular language.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Repetition extends Expression {

	/**
	* <p>The operand <code>Expression</code>.</p>
	*/
	private final Expression e1;
	/**
	* <p>The minimum number of times <code>e1</code> is repeated.</p>
	*/
	private final int min;
	/**
	* <p>The maximum number of times <code>e1</code> is repeated.</p>
	*/
	private final int max;

	/**
	* <p>Constructs an <code>Expression</code> expressing the repetition of a regular language, and builds the NFA constructed from this <code>Expression</code>. Large finite values for the minimum or maximum cause the NFA constructed from the operand <code>Expression</code> to be copied many times, resulting in a space-inefficient NFA.</p>
	*
	* @param e1 the operand <code>Expression</code>.
	* @param min the minimum number of times <code>e1</code> is repeated. If negative, it is assumed to be zero.
	* @param max the maximum number of times <code>e1</code> is repeated. If negative, it is assumed to be infinity.
	*/
	public Repetition(Expression e1, int min, int max) {
		this.e1 = e1 = (Expression)e1.clone();
		this.min = min = Math.max(min, 0);
		this.max = max;

		i = (min > 0) ? e1.i : s();
		f = (min > 0) ? e1.f : i;

		if (min == 0 && max < 0) {
			put(i, null, e1.i);
			put(e1.f, null, i);
		}
		else {
			for (int k = 2; k <= min; k++) {
				e1 = (Expression)e1.clone();
				put(f, null, e1.i);
				f = e1.f;
			}
			if (max > min) {
				Integer tail = f;
				put(tail, null, f = s());

				for (int k = min+1; k <= max; k++) {
					if (k > 1) e1 = (Expression)e1.clone();
					put(tail, null, e1.i);
					put(tail = e1.f, null, f);
				}
			}
			else if (max < 0) put(f, null, e1.i);
		}
	}

	/**
	* <p>Creates a clone of this <code>Expression</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Expression</code>.
	*/
	public Object clone() {
		return new Repetition(e1, min, max);
	}
}
//Concatenation
/**
* <p>This class implements an {@link Lexicon.Expression <code>Expression</code>} expressing the concatenation of two regular languages.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Concatenation extends Expression {

	/**
	* <p>The left operand <code>Expression</code>.</p>
	*/
	private final Expression e1;
	/**
	* <p>The right operand <code>Expression</code>.</p>
	*/
	private final Expression e2;

	/**
	* <p>Constructs an <code>Expression</code> expressing the concatenation of two regular languages, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param e1 the left operand <code>Expression</code>.
	* @param e2 the right operand <code>Expression</code>.
	*/
	public Concatenation(Expression e1, Expression e2) {
		this.e1 = e1 = (Expression)e1.clone();
		this.e2 = e2 = (Expression)e2.clone();

		i = e1.i;
		f = e2.f;

		put(e1.f, null, e2.i);
	}

	/**
	* <p>Creates a clone of this <code>Expression</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Expression</code>.
	*/
	public Object clone() {
		return new Concatenation(e1, e2);
	}
}
//Singleton
/**
* <p>This class implements an {@link Lexicon.Expression <code>Expression</code>} expressing a singleton language.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Singleton extends Expression {

	/**
	* <p>The string whose singleton language is expressed.</p>
	*/
	private final String x;

	/**
	* <p>Constructs an <code>Expression</code> expressing a singleton language, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param x the string whose singleton language is expressed.
	*/
	public Singleton(String x) {
		this.x = x;

		f = i = s();

		for (char c : x.toCharArray())
			new Match(f, c, f = s());
	}

	/**
	* <p>Creates a clone of this <code>Expression</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Expression</code>.
	*/
	public Object clone() {
		return new Singleton(x);
	}
}
//Union
/**
* <p>This class implements an {@link Lexicon.Expression <code>Expression</code>} expressing the union of two regular languages.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public static class Union extends Expression {

	/**
	* <p>The left operand <code>Expression</code>.</p>
	*/
	private final Expression e1;
	/**
	* <p>The right operand <code>Expression</code>.</p>
	*/
	private final Expression e2;

	/**
	* <p>Constructs an <code>Expression</code> expressing the union of two regular languages, and builds the NFA constructed from this <code>Expression</code>.</p>
	*
	* @param e1 the left operand <code>Expression</code>.
	* @param e2 the right operand <code>Expression</code>.
	*/
	public Union(Expression e1, Expression e2) {
		this.e1 = e1 = (Expression)e1.clone();
		this.e2 = e2 = (Expression)e2.clone();

		i = s();
		f = s();

		put(i, null, e1.i); put(e1.f, null, f);
		put(i, null, e2.i); put(e2.f, null, f);
	}

	/**
	* <p>Creates a clone of this <code>Expression</code>, and replicates the NFA constructed from this <code>Expression</code>.</p>
	*
	* @return a clone of this <code>Expression</code>.
	*/
	public Object clone() {
		return new Union(e1, e2);
	}
}

/**
* <p>The mapping representing this <code>Lexicon</code>. A terminal is mapped to the initial state of the NFA constructed from the associated <code>Expression</code>.</p>
*/
private final Map<Object, Expression> E;

/**
* <p>Puts a terminal and associated <code>Expression</code> into this <code>Lexicon</code>. The <code>Expression</code> supersedes any previously associated with the terminal.</p>
*
* @param a the terminal to add to this <code>Lexicon</code>.
* @param e the <code>Expression</code> associated with terminal <code>a</code>. When grabbing, the language expressed by <code>e</code> matches <code>a</code>.
*/
public void put(Object a, Expression e) {
	E.put(a, e);
	I.clear();
	F.clear();
}

/**
* <p>Indicates whether a symbol is a terminal in this <code>Lexicon</code>.</p>
*
* @param a the symbol whose status is requested.
* @return <code>true</code> if <code>a</code> is a terminal in this <code>Lexicon</code>; <code>false</code> otherwise.
*/
boolean terminal(Object a) {
	return E.containsKey(a);
}
//Lexicon()
/**
* <p>The terminal matched by the character at the end of a source stream.</p>
* @since 1.1, renames <code>END_OF_SOURCE</code> in version 1.0.
*/
protected static final Object $ = new String("$");

/**
* <p>The <code>Alphabet</code> containing the character at the end of a source stream.</p>
*/
private static final Expression $_EXPRESSION = new Match((char)-1);

/**
* <p>Constructs an empty <code>Lexicon</code>.</p>
*/
protected Lexicon() {
	E = new HashMap<Object, Expression>(500);
	I = new Set<Integer>(-200);
	F = new HashMap<Integer, Object>(500);
	put($, $_EXPRESSION);
}

/**
* <p>Constructs a <code>Lexicon</code> that is a shallow copy of <code>lexicon</code>. The fields of the new <code>Lexicon</code> refer to the same elements as those in <code>lexicon</code>.</p>
*
 *
* @param lexicon the <code>Lexicon</code> to copy.
*/
Lexicon(Lexicon lexicon) {/*debug*/
	debug = lexicon.debug;/*off*/
	E = lexicon.E;
	I = lexicon.I;
	F = lexicon.F;
}
//Lexicon.initial
/**
* <p>Returns the initial states of the lexical NFA.</p>
*
* @return {@link #I}, computing it and {@link #F} if there is a need to compute the current initial states and final states.
*/
private Set<Integer> initial() {

	if (I.isEmpty()) {

		for (Object a : E.keySet()) {
			Expression e = E.get(a);

			I.add(e.i);
			F.put(e.f, a);
		}
		closure(I);
	}
	return I;
}
//accept
/**
* <p>Computes the current final state, if any, in the lexical NFA.</p>
*
* @param S the current states.
* @return the maximum final state in <code>S</code>. Returns <code>null</code> if <code>S</code> contains no final states.
*/
private Integer accept(Set<Integer> S) {

	Integer
		f = null;

	for (Integer s : S)
		if (F.containsKey(s))
			if (f == null || f < s) f = s;

	return f;
}

/**
* <p>This class implements an {@link Lexicon.Exception <code>Exception</code>}.</p>
*
* @version 1.3
* @author &copy; 1999-2009 <a href="http://www.csupomona.edu/~carich/">Craig A. Rich</a> &lt;<a href="mailto:carich@csupomona.edu">carich@csupomona.edu</a>&gt;
*/
public class Exception extends java.lang.Exception {

	/**
	* <p>The extended error message.</p>
	*/
	private StringBuffer message;

	/**
	* <p>Constructs an <code>Exception</code> with a message.</p>
	*
	* @param message the error message.
	*/
	public Exception(String message) {
		super(message);
	}

	/**
	* <p>Returns the error message.</p>
	*
	* @return the error message.
	*/
	public String getMessage() {
		return (message == null) ? super.getMessage() : message.toString();
	}

	/**
	* <p>Extends the error message in this <code>Exception</code>. The extended message includes the line number, message and source characters following the error.</p>
	*
	* @param source the source character stream.
	* @return this <code>Exception</code> with an extended message.
	*/
	Exception extend(LineNumberReader source) {
		if (message == null) message = new StringBuffer(132);
		else message.setLength(0);

		message.append("line ");
		message.append(source.getLineNumber()+1);
		message.append(": ");
		message.append(super.getMessage());
		message.append(System.getProperty("line.separator"));
		message.append("...");
		message.append(word());
		try {
			String rest = source.readLine();
			if (rest != null) message.append(rest);
		}
		catch (IOException exception) {}
		message.append(System.getProperty("line.separator"));
		message.append("   ^");
		return this;
	}
}
//Lexicon.grab
/**
* <p>The states through which the lexical NFA transitions.</p>
*/
private final Set<Integer>[] R = (Set<Integer>[])new Set<?>[]{new Set<Integer>(-200), new Set<Integer>(-200)};
/**
* <p>The <code>StringBuffer</code> containing the word most recently grabbed.</p>
*/
private final StringBuffer w = new StringBuffer(4000);

/**
* <p>Grabs a terminal from a source character stream using this <code>Lexicon</code>. The variable returned by {@link #word()} is set to the longest nonempty prefix of the remaining source characters matching an <code>Expression</code> in this <code>Lexicon</code>. If no nonempty prefix matches an <code>Expression</code>, a <code>Lexicon.Exception</code> is thrown. If the longest matching prefix matches more than one <code>Expression</code>, the terminal associated with the <code>Expression</code> most recently constructed is returned. Blocks until a character is available, an I/O error occurs, or the end of the source stream is reached.</p>
*
* @param source the source character stream.
* @return the terminal grabbed from <code>source</code>.
* @throws Lexicon.Exception if an I/O or lexical error occurs.
*/
protected Object grab(LineNumberReader source) throws Exception {
	Set<Integer> S = initial();
	w.setLength(0);
	int wLength = 0;
	Object b = null;
	try {
		source.mark(w.capacity());
		do {
			int a = source.read();
			S = closure(transition(S, (char)a, R[w.length() % 2]));
			if (S.isEmpty()) break;

			if (a != -1) w.append((char)a); else w.append($);

			Integer f = accept(S);
			if (f != null) {
				wLength = w.length();
				b = F.get(f);
				source.mark(w.capacity());
			}
		} while (b != $);
		w.setLength(wLength);
		source.reset();
	}
	catch (IOException exception) {
		throw new Exception(exception.getMessage());
	}
	if (wLength == 0) throw new Exception("lexical error").extend(source);
	return b;
}

/**
* <p>Returns the word most recently grabbed using this <code>Lexicon</code>.</p>
*
* @return the word most recently grabbed by {@link #grab(java.io.LineNumberReader) <code>grab(source)</code>}.
*/
protected String word() {
	return w.substring(0);
}
//Lexicon.interpret
/**
* <p>Repeatedly invokes {@link #grab(java.io.LineNumberReader) <code>grab(source)</code>} until the end of the source stream reached. Blocks until a character is available, or an I/O error occurs. This method is overridden by <code>Grammar</code> and its parser subclasses, so it is only invoked when this <code>Lexicon</code> has not been extended into a <code>Grammar</code> or parser.</p>
*
* @param source the source character stream.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>. A <code>Lexicon</code> always returns null.
* @throws Lexicon.Exception if an I/O or lexical error occurs.
*/
Object interpret(LineNumberReader source) throws Exception {/*debug*/
	if ((debug & TERMINALS) > 0) System.out.println(
		"----terminals\n\t" + E.keySet().toString().replaceFirst("\\[", "{").replaceAll(", ", " ").replaceFirst("\\]$", "}\n----------"));/*off*/

	for (Object a; (a = grab(source)) != $;)/*debug*/
		if ((debug & LEXICAL) > 0) System.out.println(
			a + (!a.equals(word()) ? " " + word() : ""))/*off*/
		;
	return null;
}

/**
* <p>Interprets a source character stream using this <code>Lexicon</code>.</p>
*
* @param source the source character stream.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret(Reader source) throws Exception {
	return interpret(new LineNumberReader(source));
}

/**
* <p>Interprets a source string using this <code>Lexicon</code>.</p>
*
* @param source the source string.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret(String source) throws Exception {
	return interpret(new StringReader(source));
}

/**
* <p>Interprets a source byte stream using this <code>Lexicon</code>.</p>
*
* @param source the source byte stream.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret(InputStream source) throws Exception {
	return interpret(new InputStreamReader(source));
}

/**
* <p>Interprets the standard input stream using this <code>Lexicon</code>.</p>
*
* @return the <code>ParseTree</code> constructed by interpreting the standard input stream.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret() throws Exception {
	return interpret(System.in);
}

/**
* <p>Interprets a source file using this <code>Lexicon</code>.</p>
*
* @param source the source file.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>.
* @throws FileNotFoundException if the source file cannot be found.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret(File source) throws FileNotFoundException, Exception {
	return interpret(new FileReader(source));
}

/**
* <p>Interprets a source pipe using this <code>Lexicon</code>.</p>
*
* @param source the source pipe.
* @return the <code>ParseTree</code> constructed by interpreting <code>source</code>.
* @throws IOException if the source pipe cannot be connected.
* @throws Lexicon.Exception if an I/O, lexical, syntax or semantic error occurs.
*/
public Object interpret(PipedWriter source) throws IOException, Exception {
	return interpret(new PipedReader(source));
}
//Lexicon.interpret(arguments)
/**
* <p>The debug switches, initially zero. The following bits enable debugging to standard output:</p>
* <blockquote><dl>
*	<dt><code>0x01</code> = <code>TERMINALS</code></dt>
*	<dd>Print the set of terminals before lexical analysis</dd>
*	<dt><code>0x02</code> = <code>LEXICAL</code> </dt>
*	<dd>Print terminals and associated words grabbed during lexical analysis</dd>
*	<dt><code>0x04</code> = <code>FIRST_FOLLOW</code></dt>
*	<dd>Print first and follow sets precomputed during syntax analysis</dd>
*	<dt><code>0x08</code> = <code>SYNTAX</code></dt>
*	<dd>Print parsing decisions made during syntax analysis</dd>
*	<dt><code>0x10</code> = <code>CONFLICT</code></dt>
*	<dd>Print parsing conflicts encountered during syntax analysis</dd>
*	<dt><code>0x20</code> = <code>PARSE_TREE</code></dt>
*	<dd>Print each <code>ParseTree</code> produced by syntax analysis</dd>
* </dl></blockquote>
* @since 1.1
*/
protected int debug = 0;

/**
* <p>{@link #debug <code>debug</code>} switch constant enabling printing the set of terminals before lexical analysis.</p>
* @since 1.1
*/
protected static final int TERMINALS = 0x01;
/**
* <p>{@link #debug <code>debug</code>} switch constant enabling printing terminals and associated words grabbed during lexical analysis.</p>
* @since 1.1
*/
protected static final int LEXICAL = 0x02;
/**
* <p>{@link #debug <code>debug</code>} switch constant enabling all debugging.</p>
* @since 1.1
*/
protected static final int VERBOSE = 0xFF;

}