Java/Design Pattern/Interpretor Pattern

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Interpreter Pattern 2

//[C] 2002 Sun Microsystems, Inc.---
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
public class RunInterpreterPattern {
  public static void main(String[] arguments) {
    System.out.println("Example for the Interpreter pattern");
    System.out.println("In this demonstration, the syntax defined");
    System.out.println(" by the Interpreter can be used to search");
    System.out.println(" among a collection of Contacts, returning");
    System.out.println(" the subset that match the given search criteria.");
    ContactList candidates = makeContactList();
    Context ctx = new Context();
    System.out.println("Contents of the ContactList:");
    System.out.println(candidates);
    System.out.println();
    Contact testContact = new ContactImpl();
    VariableExpression varLName = new VariableExpression(testContact,
        "getLastName");
    ConstantExpression constLName = new ConstantExpression("u");
    ContainsExpression eqLName = new ContainsExpression(varLName,
        constLName);
    System.out.println("Contents of the search on ContactList:");
    System.out.println("(search was contains "u" in Lase Name)");
    Object result = candidates.getContactsMatchingExpression(eqLName, ctx,
        testContact);
    System.out.println(result);
    VariableExpression varTitle = new VariableExpression(testContact,
        "getTitle");
    ConstantExpression constTitle = new ConstantExpression("LT");
    EqualsExpression eqTitle = new EqualsExpression(varTitle, constTitle);
    System.out.println("Contents of the search on ContactList:");
    System.out.println("(search was all LT personnel)");
    result = candidates.getContactsMatchingExpression(eqTitle, ctx,
        testContact);
    System.out.println(result);
    System.out.println();
    VariableExpression varLastName = new VariableExpression(testContact,
        "getLastName");
    ConstantExpression constLastName = new ConstantExpression("S");
    ContainsExpression cLName = new ContainsExpression(varLastName,
        constLastName);
    AndExpression andExpr = new AndExpression(eqTitle, cLName);
    System.out.println("Contents of the search on ContactList:");
    System.out
        .println("(search was all LT personnel with "S" in Last Name)");
    result = candidates.getContactsMatchingExpression(andExpr, ctx,
        testContact);
    System.out.println(result);
  }
  private static ContactList makeContactList() {
    ContactList returnList = new ContactList();
    returnList.addContact(new ContactImpl("James", "Kirk", "Captain",
        "USS Enterprise"));
    returnList.addContact(new ContactImpl("Mr.", "Spock",
        "Science Officer", "USS Enterprise"));
    returnList.addContact(new ContactImpl("LT", "Uhura", "LT",
        "USS Enterprise"));
    returnList.addContact(new ContactImpl("LT", "Sulu", "LT",
        "USS Enterprise"));
    returnList.addContact(new ContactImpl("Ensign", "Checkov", "Ensign",
        "USS Enterprise"));
    returnList.addContact(new ContactImpl("Dr.", "McCoy", "Ship"s Doctor",
        "USS Enterprise"));
    returnList.addContact(new ContactImpl("Montgomery", "Scott", "LT",
        "USS Enterprise"));
    return returnList;
  }
}
interface Contact extends Serializable {
  public static final String SPACE = " ";
  public String getFirstName();
  public String getLastName();
  public String getTitle();
  public String getOrganization();
  public void setFirstName(String newFirstName);
  public void setLastName(String newLastName);
  public void setTitle(String newTitle);
  public void setOrganization(String newOrganization);
}
class ContactImpl implements Contact {
  private String firstName;
  private String lastName;
  private String title;
  private String organization;
  public ContactImpl() {
  }
  public ContactImpl(String newFirstName, String newLastName,
      String newTitle, String newOrganization) {
    firstName = newFirstName;
    lastName = newLastName;
    title = newTitle;
    organization = newOrganization;
  }
  public String getFirstName() {
    return firstName;
  }
  public String getLastName() {
    return lastName;
  }
  public String getTitle() {
    return title;
  }
  public String getOrganization() {
    return organization;
  }
  public void setFirstName(String newFirstName) {
    firstName = newFirstName;
  }
  public void setLastName(String newLastName) {
    lastName = newLastName;
  }
  public void setTitle(String newTitle) {
    title = newTitle;
  }
  public void setOrganization(String newOrganization) {
    organization = newOrganization;
  }
  public String toString() {
    return firstName + SPACE + lastName;
  }
}
class ContactList implements Serializable {
  private ArrayList contacts = new ArrayList();
  public ArrayList getContacts() {
    return contacts;
  }
  public Contact[] getContactsAsArray() {
    return (Contact[]) (contacts.toArray(new Contact[1]));
  }
  public ArrayList getContactsMatchingExpression(Expression expr,
      Context ctx, Object key) {
    ArrayList results = new ArrayList();
    Iterator elements = contacts.iterator();
    while (elements.hasNext()) {
      Object currentElement = elements.next();
      ctx.addVariable(key, currentElement);
      expr.interpret(ctx);
      Object interpretResult = ctx.get(expr);
      if ((interpretResult != null)
          && (interpretResult.equals(Boolean.TRUE))) {
        results.add(currentElement);
      }
    }
    return results;
  }
  public void setContacts(ArrayList newContacts) {
    contacts = newContacts;
  }
  public void addContact(Contact element) {
    if (!contacts.contains(element)) {
      contacts.add(element);
    }
  }
  public void removeContact(Contact element) {
    contacts.remove(element);
  }
  public String toString() {
    return contacts.toString();
  }
}
class Context {
  private HashMap map = new HashMap();
  public Object get(Object name) {
    return map.get(name);
  }
  public void addVariable(Object name, Object value) {
    map.put(name, value);
  }
}
interface Expression {
  void interpret(Context c);
}
class OrExpression extends CompoundExpression {
  public OrExpression(ComparisonExpression expressionA,
      ComparisonExpression expressionB) {
    super(expressionA, expressionB);
  }
  public void interpret(Context c) {
    expressionA.interpret(c);
    expressionB.interpret(c);
    Boolean result = new Boolean(((Boolean) c.get(expressionA))
        .booleanValue()
        || ((Boolean) c.get(expressionB)).booleanValue());
    c.addVariable(this, result);
  }
}
abstract class CompoundExpression implements Expression {
  protected ComparisonExpression expressionA;
  protected ComparisonExpression expressionB;
  public CompoundExpression(ComparisonExpression expressionA,
      ComparisonExpression expressionB) {
    this.expressionA = expressionA;
    this.expressionB = expressionB;
  }
}
class ConstantExpression implements Expression {
  private Object value;
  public ConstantExpression(Object newValue) {
    value = newValue;
  }
  public void interpret(Context c) {
    c.addVariable(this, value);
  }
}
abstract class ComparisonExpression implements Expression {
  protected Expression expressionA;
  protected Expression expressionB;
  public ComparisonExpression(Expression expressionA, Expression expressionB) {
    this.expressionA = expressionA;
    this.expressionB = expressionB;
  }
}
class AndExpression extends CompoundExpression {
  public AndExpression(ComparisonExpression expressionA,
      ComparisonExpression expressionB) {
    super(expressionA, expressionB);
  }
  public void interpret(Context c) {
    expressionA.interpret(c);
    expressionB.interpret(c);
    Boolean result = new Boolean(((Boolean) c.get(expressionA))
        .booleanValue()
        && ((Boolean) c.get(expressionB)).booleanValue());
    c.addVariable(this, result);
  }
}
class VariableExpression implements Expression {
  private Object lookup;
  private String methodName;
  public VariableExpression(Object newLookup, String newMethodName) {
    lookup = newLookup;
    methodName = newMethodName;
  }
  public void interpret(Context c) {
    try {
      Object source = c.get(lookup);
      if (source != null) {
        Method method = source.getClass().getMethod(methodName, null);
        Object result = method.invoke(source, null);
        c.addVariable(this, result);
      }
    } catch (NoSuchMethodException exc) {
    } catch (IllegalAccessException exc) {
    } catch (InvocationTargetException exc) {
    }
  }
}
class EqualsExpression extends ComparisonExpression {
  public EqualsExpression(Expression expressionA, Expression expressionB) {
    super(expressionA, expressionB);
  }
  public void interpret(Context c) {
    expressionA.interpret(c);
    expressionB.interpret(c);
    Boolean result = new Boolean(c.get(expressionA).equals(
        c.get(expressionB)));
    c.addVariable(this, result);
  }
}
class ContainsExpression extends ComparisonExpression {
  public ContainsExpression(Expression expressionA, Expression expressionB) {
    super(expressionA, expressionB);
  }
  public void interpret(Context c) {
    expressionA.interpret(c);
    expressionB.interpret(c);
    Object exprAResult = c.get(expressionA);
    Object exprBResult = c.get(expressionB);
    if ((exprAResult instanceof String) && (exprBResult instanceof String)) {
      if (((String) exprAResult).indexOf((String) exprBResult) != -1) {
        c.addVariable(this, Boolean.TRUE);
        return;
      }
    }
    c.addVariable(this, Boolean.FALSE);
    return;
  }
}





Interpreter Pattern: Calculator

/*
Software Architecture Design Patterns in Java
by Partha Kuchana 
Auerbach Publications
*/

import java.util.HashMap;
import java.util.Stack;
public class Calculator {
  private String expression;
  private HashMap operators;
  private Context ctx;
  public static void main(String[] args) {
    Calculator calc = new Calculator();
    //instantiate the context
    Context ctx = new Context();
    //set the expression to evaluate
    calc.setExpression("(a+b)*(c-d)");
    //configure the calculator with the
    // Context
    calc.setContext(ctx);
    //Display the result
    System.out.println(" Variable Values: " + "a=" + ctx.getValue("a")
        + ", b=" + ctx.getValue("b") + ", c=" + ctx.getValue("c")
        + ", d=" + ctx.getValue("d"));
    System.out.println(" Expression = (a+b)*(c-d)");
    System.out.println(" Result = " + calc.evaluate());
  }
  public Calculator() {
    operators = new HashMap();
    operators.put("+", "1");
    operators.put("-", "1");
    operators.put("/", "2");
    operators.put("*", "2");
    operators.put("(", "0");
  }
  public void setContext(Context c) {
    ctx = c;
  }
  public void setExpression(String expr) {
    expression = expr;
  }
  public int evaluate() {
    //infix to Postfix
    String pfExpr = infixToPostFix(expression);
    //build the Binary Tree
    Expression rootNode = buildTree(pfExpr);
    //Evaluate the tree
    return rootNode.evaluate(ctx);
  }
  private NonTerminalExpression getNonTerminalExpression(String operation,
      Expression l, Expression r) {
    if (operation.trim().equals("+")) {
      return new AddExpression(l, r);
    }
    if (operation.trim().equals("-")) {
      return new SubtractExpression(l, r);
    }
    if (operation.trim().equals("*")) {
      return new MultiplyExpression(l, r);
    }
    return null;
  }
  private Expression buildTree(String expr) {
    Stack s = new Stack();
    for (int i = 0; i < expr.length(); i++) {
      String currChar = expr.substring(i, i + 1);
      if (isOperator(currChar) == false) {
        Expression e = new TerminalExpression(currChar);
        s.push(e);
      } else {
        Expression r = (Expression) s.pop();
        Expression l = (Expression) s.pop();
        Expression n = getNonTerminalExpression(currChar, l, r);
        s.push(n);
      }
    }//for
    return (Expression) s.pop();
  }
  private String infixToPostFix(String str) {
    Stack s = new Stack();
    String pfExpr = "";
    String tempStr = "";
    String expr = str.trim();
    for (int i = 0; i < str.length(); i++) {
      String currChar = str.substring(i, i + 1);
      if ((isOperator(currChar) == false) && (!currChar.equals("("))
          && (!currChar.equals(")"))) {
        pfExpr = pfExpr + currChar;
      }
      if (currChar.equals("(")) {
        s.push(currChar);
      }
      //for ")" pop all stack contents until "("
      if (currChar.equals(")")) {
        tempStr = (String) s.pop();
        while (!tempStr.equals("(")) {
          pfExpr = pfExpr + tempStr;
          tempStr = (String) s.pop();
        }
        tempStr = "";
      }
      //if the current character is an
      // operator
      if (isOperator(currChar)) {
        if (s.isEmpty() == false) {
          tempStr = (String) s.pop();
          String strVal1 = (String) operators.get(tempStr);
          int val1 = new Integer(strVal1).intValue();
          String strVal2 = (String) operators.get(currChar);
          int val2 = new Integer(strVal2).intValue();
          while ((val1 >= val2)) {
            pfExpr = pfExpr + tempStr;
            val1 = -100;
            if (s.isEmpty() == false) {
              tempStr = (String) s.pop();
              strVal1 = (String) operators.get(tempStr);
              val1 = new Integer(strVal1).intValue();
            }
          }
          if ((val1 < val2) && (val1 != -100))
            s.push(tempStr);
        }
        s.push(currChar);
      }//if
    }// for
    while (s.isEmpty() == false) {
      tempStr = (String) s.pop();
      pfExpr = pfExpr + tempStr;
    }
    return pfExpr;
  }
  private boolean isOperator(String str) {
    if ((str.equals("+")) || (str.equals("-")) || (str.equals("*"))
        || (str.equals("/")))
      return true;
    return false;
  }
} // End of class
class Context {
  private HashMap varList = new HashMap();
  public void assign(String var, int value) {
    varList.put(var, new Integer(value));
  }
  public int getValue(String var) {
    Integer objInt = (Integer) varList.get(var);
    return objInt.intValue();
  }
  public Context() {
    initialize();
  }
  //Values are hardcoded to keep the example simple
  private void initialize() {
    assign("a", 20);
    assign("b", 40);
    assign("c", 30);
    assign("d", 10);
  }
}
class TerminalExpression implements Expression {
  private String var;
  public TerminalExpression(String v) {
    var = v;
  }
  public int evaluate(Context c) {
    return c.getValue(var);
  }
}
interface Expression {
  public int evaluate(Context c);
}
abstract class NonTerminalExpression implements Expression {
  private Expression leftNode;
  private Expression rightNode;
  public NonTerminalExpression(Expression l, Expression r) {
    setLeftNode(l);
    setRightNode(r);
  }
  public void setLeftNode(Expression node) {
    leftNode = node;
  }
  public void setRightNode(Expression node) {
    rightNode = node;
  }
  public Expression getLeftNode() {
    return leftNode;
  }
  public Expression getRightNode() {
    return rightNode;
  }
}// NonTerminalExpression
class AddExpression extends NonTerminalExpression {
  public int evaluate(Context c) {
    return getLeftNode().evaluate(c) + getRightNode().evaluate(c);
  }
  public AddExpression(Expression l, Expression r) {
    super(l, r);
  }
}// AddExpression
class SubtractExpression extends NonTerminalExpression {
  public int evaluate(Context c) {
    return getLeftNode().evaluate(c) - getRightNode().evaluate(c);
  }
  public SubtractExpression(Expression l, Expression r) {
    super(l, r);
  }
}// SubtractExpression
class MultiplyExpression extends NonTerminalExpression {
  public int evaluate(Context c) {
    return getLeftNode().evaluate(c) * getRightNode().evaluate(c);
  }
  public MultiplyExpression(Expression l, Expression r) {
    super(l, r);
  }
}// MultiplyExpression

//File: Interprepter.properties
/*
a=10
b=20
c=30
d=40
*/





Interpreter pattern in Java

/*
The Design Patterns Java Companion
Copyright (C) 1998, by James W. Cooper
IBM Thomas J. Watson Research Center
*/
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.StringTokenizer;
import java.util.Vector;
import javax.swing.AbstractListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
//-----------------------------------
public class InterpDemo extends JFrame implements ActionListener {
  JButton Go;
  JTextField tx;
  KidData kdata;
  JawtList ptable;
  public InterpDemo() {
    super("Interpreter Demo");
    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    tx = new JTextField(20);
    Go = new JButton("Go");
    JPanel p = new JPanel();
    getContentPane().add(p);
    p.setLayout(new BorderLayout());
    JPanel np = new JPanel();
    p.add("North", np);
    np.add(tx);
    np.add(Go);
    Go.addActionListener(this);
    ptable = new JawtList(20);
    p.add("Center", ptable);
    kdata = new KidData("50free.txt");
    setSize(new Dimension(400, 200));
    setVisible(true);
  }
  //----------------------------------------
  public void actionPerformed(ActionEvent e) {
    Parser p = new Parser(tx.getText());
    p.setData(kdata, ptable);
    p.Execute();
  }
  //----------------------------------------
  static public void main(String argv[]) {
    new InterpDemo();
  }
}
interface Command {
  public void Execute();
}
//this class is just a simple collection of arrays
//of the data which has been selected
class Data {
  Kid[] kids;
  public Data(Kid[] kd) {
    kids = kd;
  }
  public Kid[] getData() {
    return kids;
  }
}
class ParseVar extends ParseObject {
  static final int FRNAME = 0, LNAME = 1, AGE = 2, CLUB = 3, TIME = 4,
      tabMAX = 5;
  public ParseVar(String s) {
    s = s.toLowerCase();
    value = -1;
    type = VAR;
    if (s.equals("frname"))
      value = FRNAME;
    if (s.equals("lname"))
      value = LNAME;
    if (s.equals("age"))
      value = AGE;
    if (s.equals("club"))
      value = CLUB;
    if (s.equals("time"))
      value = TIME;
  }
  //--------------------------------------
  public boolean isLegal() {
    return (value >= 0);
  }
}
class Parser implements Command {
  Stack stk;
  Vector actionList;
  KidData kdata;
  Data data;
  //PrintTable ptable;
  JawtList ptable;
  public Parser(String line) {
    stk = new Stack();
    actionList = new Vector();
    StringTokenizer tok = new StringTokenizer(line);
    while (tok.hasMoreElements()) {
      ParseObject token = tokenize(tok.nextToken());
      if (token != null)
        stk.push(token);
    }
  }
  //----------------------------------------
  public void setData(KidData k, JawtList pt) {
    data = new Data(k.getData());
    ptable = pt;
  }
  //----------------------------------------
  //executes parse of command line
  public void Execute() {
    while (stk.hasMoreElements()) {
      if (topStack(ParseObject.VAR, ParseObject.VAR)) {
        //reduce (Var Var) to Multvar
        ParseVar v = (ParseVar) stk.pop();
        ParseVar v1 = (ParseVar) stk.pop();
        MultVar mv = new MultVar(v1, v);
        stk.push(mv);
      }
      //reduce MULTVAR VAR to MULTVAR
      if (topStack(ParseObject.MULTVAR, ParseObject.VAR)) {
        MultVar mv = new MultVar();
        MultVar mvo = (MultVar) stk.pop();
        ParseVar v = (ParseVar) stk.pop();
        mv.add(v);
        Vector mvec = mvo.getVector();
        for (int i = 0; i < mvec.size(); i++)
          mv.add((ParseVar) mvec.elementAt(i));
        stk.push(mv);
      }
      if (topStack(ParseObject.VAR, ParseObject.MULTVAR)) {
        //reduce (Multvar Var) to Multvar
        ParseVar v = (ParseVar) stk.pop();
        MultVar mv = (MultVar) stk.pop();
        mv.add(v);
        stk.push(mv);
      }
      //reduce Verb Var to Verb containing vars
      if (topStack(ParseObject.VAR, ParseObject.VERB)) {
        addArgsToVerb();
      }
      //reduce Verb MultVar to Verb containing vars
      if (topStack(ParseObject.MULTVAR, ParseObject.VERB)) {
        addArgsToVerb();
      }
      //move top verb to action list
      if (stk.top().getType() == ParseObject.VERB) {
        actionList.addElement(stk.pop());
      }
    }//while
    //now execute the verbs
    //data.setData(kdata.getData());
    //for (int i = actionList.size() -1; i >= 0; i--)
    for (int i = 0; i < actionList.size(); i++) {
      Verb v = (Verb) actionList.elementAt(i);
      v.setData(data, ptable);
      v.Execute();
    }
  }
  //----------------------------------------
  private void addArgsToVerb() {
    ParseObject v = stk.pop();
    ParseVerb verb = (ParseVerb) stk.pop();
    verb.addArgs(v);
    stk.push(verb);
  }
  //----------------------------------------
  private boolean topStack(int c1, int c2) {
    return (stk.top().getType() == c1) && (stk.nextTop().getType() == c2);
  }
  //----------------------------------------
  private ParseObject tokenize(String s) {
    ParseObject obj = getVerb(s);
    if (obj == null)
      obj = getVar(s);
    return obj;
  }
  //----------------------------------------
  private ParseVerb getVerb(String s) {
    ParseVerb v;
    v = new ParseVerb(s);
    if (v.isLegal())
      return v.getVerb(s);
    else
      return null;
  }
  //----------------------------------------
  private ParseVar getVar(String s) {
    ParseVar v;
    v = new ParseVar(s);
    if (v.isLegal())
      return v;
    else
      return null;
  }
}
class Kid {
  String frname, lname, club;
  int age;
  float time;
  //-------------------------------------
  public Kid(String line) {
    StringTokenizer tok = new StringTokenizer(line);
    String lnum = tok.nextToken();
    frname = tok.nextToken();
    lname = tok.nextToken();
    age = new Integer(tok.nextToken()).intValue();
    club = tok.nextToken();
    time = new Float(tok.nextToken()).floatValue();
  }
  //-------------------------------
  public Object getData(int key) {
    switch (key) {
    case ParseVar.FRNAME:
      return frname;
    case ParseVar.LNAME:
      return lname;
    case ParseVar.CLUB:
      return club;
    case ParseVar.AGE:
      return new Integer(age);
    case ParseVar.TIME:
      return new Float(time);
    }
    return null;
  }
  //--------------------------------
  public int getAge() {
    return age;
  }
  public float getTime() {
    return time;
  }
  public String getFrname() {
    return frname;
  }
  public String getLname() {
    return lname;
  }
  public String getClub() {
    return club;
  }
}
interface awtList {
  public void add(String s);
  public void remove(String s);
  public String[] getSelectedItems();
}
//this is a simple adapter class to
//convert List awt methods to Swing methods
class JawtList extends JScrollPane implements ListSelectionListener, awtList {
  private JList listWindow;
  private JListData listContents;
  //-----------------------------------------
  public JawtList(int rows) {
    listContents = new JListData();
    listWindow = new JList(listContents);
    listWindow.setPrototypeCellValue("Abcdefg Hijkmnop");
    getViewport().add(listWindow);
  }
  //-----------------------------------------
  public void add(String s) {
    listContents.addElement(s);
  }
  //-----------------------------------------
  public void remove(String s) {
    listContents.removeElement(s);
  }
  //-----------------------------------------
  public void clear() {
    listContents.clear();
  }
  //-----------------------------------------
  public String[] getSelectedItems() {
    Object[] obj = listWindow.getSelectedValues();
    String[] s = new String[obj.length];
    for (int i = 0; i < obj.length; i++)
      s[i] = obj[i].toString();
    return s;
  }
  //-----------------------------------------
  public void valueChanged(ListSelectionEvent e) {
  }
}
//  =========================================
class JListData extends AbstractListModel {
  private Vector data;
  //-----------------------------------------
  public JListData() {
    data = new Vector();
  }
  //-----------------------------------------
  public int getSize() {
    return data.size();
  }
  //-----------------------------------------
  public Object getElementAt(int index) {
    return data.elementAt(index);
  }
  //-----------------------------------------
  public void addElement(String s) {
    data.addElement(s);
    fireIntervalAdded(this, data.size() - 1, data.size());
  }
  //-----------------------------------------
  public void removeElement(String s) {
    data.removeElement(s);
    fireIntervalRemoved(this, 0, data.size());
  }
  //-----------------------------------------
  public void clear() {
    int size = data.size();
    data = new Vector();
    fireIntervalRemoved(this, 0, size);
  }
}
class ParseObject {
  public static final int VERB = 1000, VAR = 1010, MULTVAR = 1020;
  protected int value;
  protected int type;
  public int getValue() {
    return value;
  }
  public int getType() {
    return type;
  }
}
class ParseVerb extends ParseObject {
  static public final int PRINT = 100, SORTBY = 110, THENBY = 120;
  protected Vector args;
  public ParseVerb(String s) {
    args = new Vector();
    s = s.toLowerCase();
    value = -1;
    type = VERB;
    if (s.equals("print"))
      value = PRINT;
    if (s.equals("sortby"))
      value = SORTBY;
  }
  //-----------------------------------
  public ParseVerb getVerb(String s) {
    switch (value) {
    case PRINT:
      return new Print(s);
    case SORTBY:
      return new Sort(s);
    }
    return null;
  }
  //-----------------------------------
  public void addArgs(MultVar mv) {
    args = mv.getVector();
  }
  //-----------------------------------
  public void addArgs(ParseObject p) {
    args.addElement(p);
  }
  //-----------------------------------
  public boolean isLegal() {
    return (value >= 0);
  }
  //-----------------------------------
}
class Sort extends Verb {
  Kid[] kids;
  int pindex;
  public Sort(String s) {
    super(s);
    value = SORTBY;
  }
  //-----------------------------------
  public void Execute() {
    int sortKey;
    kids = data.getData();
    for (int a = 0; a < args.size(); a++) {
      ParseVar v = (ParseVar) args.elementAt(a);
      if (v instanceof MultVar) {
        MultVar mv = (MultVar) v;
        Vector mvec = mv.getVector();
        for (int k = mvec.size() - 1; k >= 0; k--) {
          ParseVar pv = (ParseVar) mvec.elementAt(k);
          sortKey = pv.getValue();
          sortByKey(sortKey);
        }
      } else {
        sortKey = v.getValue();
        sortByKey(sortKey);
      }
    }
  }
  //----------------------------------------
  private void sortByKey(int sortkey) {
    System.out.println(sortkey);
    for (int i = 0; i < kids.length; i++)
      for (int j = i + 1; j < kids.length; j++)
        if (compare(i, j, sortkey)) {
          Kid tmp = kids[i];
          kids[i] = kids[j];
          kids[j] = tmp;
        }
  }
  //----------------------------------------
  private boolean compare(int i, int j, int key) {
    boolean cval;
    switch (key) {
    case ParseVar.FRNAME:
      cval = kids[i].getFrname().rupareTo(kids[j].getFrname()) > 0;
      break;
    case ParseVar.LNAME:
      cval = kids[i].getLname().rupareTo(kids[j].getLname()) > 0;
      break;
    case ParseVar.CLUB:
      cval = kids[i].getClub().rupareTo(kids[j].getClub()) > 0;
      break;
    case ParseVar.AGE:
      cval = kids[i].getAge() > kids[j].getAge();
      break;
    case ParseVar.TIME:
      cval = kids[i].getTime() > kids[j].getTime();
      break;
    default:
      cval = false;
    }
    return cval;
  }
}
class Verb extends ParseVerb implements Command {
  protected Data data;
  protected JawtList ptable;
  public Verb(String s) {
    super(s);
  }
  public void Execute() {
  }
  public void setData(Data dt, JawtList pt) {
    data = dt;
    ptable = pt;
  }
}
class Print extends Verb {
  Kid[] kids;
  public Print(String s) {
    super(s);
    value = PRINT;
  }
  //-----------------------------------
  public void Execute() {
    String pline;
    kids = data.getData();
    //ptable.setDims(kids.length, args.size());
    ptable.clear();
    for (int i = 0; i < kids.length; i++) {
      pline = ""; //line in output list
      for (int j = 0; j < args.size(); j++) {
        ParseVar v = (ParseVar) args.elementAt(j);
        if (v instanceof MultVar) {
          MultVar mv = (MultVar) v;
          Vector vlist = mv.getVector();
          for (int k = 0; k < vlist.size(); k++) {
            ParseVar pv = (ParseVar) vlist.elementAt(k);
            //System.out.print(kids[i].getData(pv.getValue())+" ");
            pline += kids[i].getData(pv.getValue()) + "   ";
          }
        } else {
          // System.out.print(kids[i].getData(v.getValue())+" ");
          //ptable.setValueAt( kids[i].getData(v.getValue()), i, j);
          pline += kids[i].getData(v.getValue()) + "   ";
        }
      }
      ptable.add(pline);
      //System.out.println();
    }
    ptable.validate();
    ptable.repaint();
  }
  //-----------------------------------
}
class MultVar extends ParseVar {
  Vector multVec;
  public MultVar(ParseObject v1, ParseObject v2) {
    super("");
    multVec = new Vector();
    multVec.addElement(v1);
    multVec.addElement(v2);
    type = MULTVAR;
  }
  public MultVar() {
    super("");
    multVec = new Vector();
    type = MULTVAR;
  }
  public void add(ParseObject v1) {
    multVec.addElement(v1);
  }
  public Vector getVector() {
    return multVec;
  }
}
class KidData {
  Vector kids;
  //------------------------------------------
  public KidData(String filename) {
    kids = new Vector();
    InputFile f = new InputFile(filename);
    String s = f.readLine();
    while (s != null) {
      if (s.trim().length() > 0) {
        Kid k = new Kid(s);
        kids.addElement(k);
      }
      s = f.readLine();
    }
  }
  //--------------------------------
  public Kid[] getData() {
    Kid[] kd = new Kid[kids.size()];
    for (int i = 0; i < kids.size(); i++)
      kd[i] = (Kid) kids.elementAt(i);
    return kd;
  }
  //--------------------------------
  public int size() {
    return kids.size();
  }
  //--------------------------------
  public Kid getKid(int i) {
    return (Kid) kids.elementAt(i);
  }
  //--------------------------------
  public Vector getKidData(int key) {
    Vector v = new Vector();
    for (int i = 0; i < kids.size(); i++)
      v.addElement(getKid(i).getData(key));
    return v;
  }
  //--------------------------------
  public int getTableKey(String tabName) {
    int key = -1;
    tabName = tabName.toLowerCase();
    if (tabName.equals("frname"))
      key = ParseVar.FRNAME;
    if (tabName.equals("lname"))
      key = ParseVar.LNAME;
    if (tabName.equals("age"))
      key = ParseVar.AGE;
    if (tabName.equals("club"))
      key = ParseVar.CLUB;
    if (tabName.equals("time"))
      key = ParseVar.TIME;
    return key;
  }
  //----------------------------
  public String getTableName(int i) {
    String name = "";
    switch (i) {
    case ParseVar.FRNAME:
      name = "frname";
    case ParseVar.LNAME:
      name = "lname";
    case ParseVar.AGE:
      name = "age";
    case ParseVar.CLUB:
      name = "club";
    case ParseVar.TIME:
      name = "time";
    }
    return name;
  }
  //----------------------------
}
class InputFile {
  RandomAccessFile f = null;
  boolean errflag;
  String s = null;
  public InputFile(String fname) {
    errflag = false;
    try {
      //open file
      f = new RandomAccessFile(fname, "r");
    } catch (IOException e) {
      //print error if not found
      System.out.println("no file found");
      errflag = true; //and set flag
    }
  }
  //-----------------------------------------
  public boolean checkErr() {
    return errflag;
  }
  //-----------------------------------------
  public String read() {
    //read a single field up to a comma or end of line
    String ret = "";
    if (s == null) //if no data in string
    {
      s = readLine(); //read next line
    }
    if (s != null) //if there is data
    {
      s.trim(); //trim off blanks
      int i = s.indexOf(","); //find next comma
      if (i <= 0) {
        ret = s.trim(); //if no commas go to end of line
        s = null; //and null out stored string
      } else {
        ret = s.substring(0, i).trim(); //return left of comma
        s = s.substring(i + 1); //save right of comma
      }
    } else
      ret = null;
    return ret; //return string
  }
  //-----------------------------------------
  public String readLine() {
    //read in a line from the file
    s = null;
    try {
      s = f.readLine(); //could throw error
    } catch (IOException e) {
      errflag = true;
      System.out.println("File read error");
    }
    return s;
  }
  //-----------------------------------------
  public void close() {
    try {
      f.close(); //close file
    } catch (IOException e) {
      System.out.println("File close error");
      errflag = true;
    }
  }
  //-----------------------------------------
}
class Stack {
  Vector stk;
  public Stack() {
    stk = new Vector();
  }
  //----------------------------------------
  public void push(Object obj) {
    stk.addElement(obj);
  }
  //----------------------------------------
  public ParseObject pop() {
    ParseObject obj = (ParseObject) stk.lastElement();
    int i = stk.size() - 1;
    stk.removeElementAt(i);
    return obj;
  }
  //----------------------------------------
  public void dump(String s) {
    System.out.println(s);
    dump();
  }
  //----------------------------------------
  public void dump() {
    for (int i = 0; i < stk.size(); i++) {
      ParseObject p = (ParseObject) stk.elementAt(i);
      System.out.println(i + " " + p.getType());
    }
  }
  //----------------------------------------
  public ParseObject top() {
    return (ParseObject) stk.lastElement();
  }
  //----------------------------------------
  public boolean hasMoreElements() {
    return (stk.size() > 0);
  }
  //----------------------------------------
  public ParseObject nextTop() {
    int i = stk.size();
    if (i > 1) {
      return (ParseObject) stk.elementAt(i - 2);
    } else
      return null;
  }
  //----------------------------------------
  public void pop2Push(ParseObject p) {
    int i = stk.size();
    if (i >= 2) {
      pop();
      pop();
      push(p);
    } else
      push(p);
  }
}
//50free.txt
/*
1 Amanda McCarthy             12  WCA         29.28
2 Jamie Falco                 12  HNHS        29.80
3 Meaghan O"Donnell           12  EDST        30.00
4 Greer Gibbs                 12  CDEV        30.04
5 Rhiannon Jeffrey            11  WYW         30.04
6 Sophie Connolly             12  WAC         30.05
7 Dana Helyer                 12  ARAC        30.18
8 Lindsay Marotto             12  OAK         30.23
9 Sarah Treichel              12  WYW         30.35
10 Ashley McEntee             12  RAC         30.47
11 Rachel Brookman            12  CAT         30.51
12 Michelle Ducharme          12  LEHY        30.51
13 Karleen Danais             12  NES         30.70
14 Megan Loock                12  WAC         30.90
15 Kaitlyn Ament              12  HNHS        30.93
16 Tara Schoen                12  WYW         31.01
17 Kate Olshefski             12  NCY         31.01
18 Emma Zuidema               12  HMST        31.07
19 Katie Persing              12  OAK         31.14
20 Christina Monsees          11  RAC         31.27
21 Kimberly Watcke            12  CDEV        31.50
22 Colleen Smith              12  AJSC        31.52
23 Chloe Osborne              12  GYWD        31.74
24 Natalia Fugate             12  WAC         31.75
25 Lisa McHale                11  RAC         31.76
26 Lindsay Cowles             11  NES         31.79
27 Jacquelyn Yavarone         12  HNHS        31.83
28 Molly Fenn                 12  WRAT        31.84
29 Karin Brudvig              12  HMST        31.84
30 Annie Duffy                12  MGAT        31.90
31 Nicole Coia                11  WCA         31.94
32 Elizabeth Rice             12  WYW         31.96
33 Yvette Landwehr            12  WRAT        32.00
34 Ashley Recklet             12  SHEL        32.24
35 Lauren McKenna             11  PSDY        32.27
36 Kristen Fontaine           12  EDST        32.28
37 Diana Cooke                12  ZEUS        32.33
38 Kimberly Gambino           11  NES         32.43
39 Jenny Morgan               11  NES         32.49
40 Colleen Coelho             12  CDEV        32.50
41 Leigh Gordon               12  CDEV        32.62
42 Caitlin Gillen             12  WYW         32.75
43 Kristen Skroski            12  HNHS        32.91
44 Sarah Greenberg            11  CDEV        32.97
45 Kathy Collins              12  EHBB        33.11
46 Morgan Bullock             12  ICSC        33.33
47 Brittany Medlin            12  CAT         33.33
48 Haley Ottenbreit           12  HNHS        33.35
49 Laura Kunces               11  WAC         33.64
50 Hayley Wolfgruber          12  WYW         33.73
51 Katie Duffy                12  MGAT        34.24

*/