import java.util.*;
import java.util.zip.*;
import java.util.List;
import java.util.regex.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.table.*;
import java.io.*;
import java.net.*;
import java.lang.reflect.*;
import java.lang.ref.*;
import java.lang.management.*;
import java.security.*;
import java.security.spec.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import java.math.*;
public class main {


public static void main(String[] args) throws Exception {
  makeBot("Decode Unicode Bot.");
}

static String answer(String s) {
  return bytesToHex(charsToDoubleBytes(s));
}

  public static String bytesToHex(byte[] bytes) {
    return bytesToHex(bytes, 0, bytes.length);
  }

  public static String bytesToHex(byte[] bytes, int ofs, int len) {
    StringBuilder stringBuilder = new StringBuilder(len*2);
    for (int i = 0; i < len; i++) {
      String s = "0" + Integer.toHexString(bytes[ofs+i]);
      stringBuilder.append(s.substring(s.length()-2, s.length()));
    }
    return stringBuilder.toString();
  }

static byte[] charsToDoubleBytes(String s) {
  byte[] b = new byte[l(s)*2];
  for (int i = 0; i < l(s); i++) {
    int x = (int) s.charAt(i);
    b[i*2] = (byte) (x >> 8);
    b[i*2+1] = (byte) x;
  }
  return b;
}
static int makeBot(String greeting) {
  return makeAndroid3(greeting).port;
}

static void makeBot(Android3 a) {
  makeAndroid3(a);
}

static Android3 makeBot(String greeting, Object responder) {
  Android3 a = new Android3(greeting);
  a.responder = makeResponder(responder);
  makeBot(a);
  return a;
}


static String makeResponder_callAnswerMethod(Object bot, String s, List<String> history) {
  String answer = (String) callOpt(bot, "answer", s, history);
  if (answer == null)
    answer = (String) callOpt(bot, "answer", s);
  return answer;
}

static Responder makeResponder(final Object bot) {
  if (bot instanceof Responder) return (Responder) bot;
  
  return new Responder() {
    String answer(String s, List<String> history) {
      return makeResponder_callAnswerMethod(bot, s, history);
    }
  };
}
static class Android3 {
  String greeting;
  boolean publicOverride; // optionally set this in client
  int startPort = 5000; // optionally set this in client
  Responder responder;
  boolean console = true;
  boolean daemon = false;
  boolean incomingSilent = false;
  boolean useMultiPort = true;
  boolean verbose;
  
  // set by system
  int port;
  long vport;
  DialogHandler handler;
  ServerSocket server;
  
  Android3(String greeting) {
  this.greeting = greeting;}
  Android3() {}
  
  synchronized void dispose() {
    if (server != null) {
      try {
        server.close();
      } catch (IOException e) {
        print("[internal] " + e);
      }
      server = null;
    }
    if (vport != 0) try { /* pcall 1*/ 
      //print("Dispoing virtual port " + vport);
      removeFromMultiPort(vport);
      vport = 0;
    /* pcall 2 */ } catch (Throwable __e) { printStackTrace(__e); }
  }
}

static abstract class Responder {
  abstract String answer(String s, List<String> history);
}

static Android3 makeAndroid3(final String greeting) {
  return makeAndroid3(new Android3(greeting));
}

static Android3 makeAndroid3(final String greeting, Responder responder) {
  Android3 android = new Android3(greeting);
  android.responder = responder;
  return makeAndroid3(android);
}

static Android3 makeAndroid3(final Android3 a) {
  if (a.responder == null)
    a.responder = new Responder() {
      String answer(String s, List<String> history) {
        return callStaticAnswerMethod(s, history);
      }
    };
    
  print(a.greeting);
  
  if (a.useMultiPort) {
    a.vport = addToMultiPort(a.greeting,
      makeAndroid3_verboseResponder(a));
    if (a.vport == 1)
      makeAndroid3_handleConsole(a);
    return a;
  }
    
  a.handler = makeAndroid3_makeDialogHandler(a);
  a.port = a.daemon
    ? startDialogServerOnPortAboveDaemon(a.startPort, a.handler)
    : startDialogServerOnPortAbove(a.startPort, a.handler);
  a.server = startDialogServer_serverSocket;

  if (a.console && makeAndroid3_consoleInUse()) a.console = false;
  
  if (a.console)
    makeAndroid3_handleConsole(a);

  record(a);
  return a;
}

static void makeAndroid3_handleConsole(final Android3 a) {
  // Console handling stuff
  print("You may also type on this console.");
  { Thread _t_0 = new Thread() {
public void run() { try { /* pcall 1*/ 
    List<String> history = new ArrayList<String>();
    String line;
    while ((line = readLine()) != null) {
      /*if (eq(line, "bye")) {
        print("> bye stranger");
        history = new ArrayList<S>();
      } else*/ {
        history.add(line);
        history.add(makeAndroid3_getAnswer(line, history, a)); // prints answer on console too
      }
    }
  /* pcall 2 */ } catch (Throwable __e) { printStackTrace(__e); } }
};
_t_0.start(); }
}

static DialogHandler makeAndroid3_makeDialogHandler(final Android3 a) {
  return new DialogHandler() {
public void run(final DialogIO io) {
    if (!a.publicOverride && !(publicCommOn() || io.isLocalConnection())) {
      io.sendLine("Sorry, not allowed");
      return;
    }
    
    String dialogID = randomID(8);
    
    io.sendLine(a.greeting + " / Your ID: " + dialogID);
    
    List<String> history = new ArrayList<String>();
    
    while (io.isStillConnected()) {
      if (io.waitForLine()) {
        final String line = io.readLineNoBlock();
        String s = dialogID + " at " + now() + ": " + quote(line);
        if (!a.incomingSilent)
          print(s);
        if (eq(line, "bye")) {
          io.sendLine("bye stranger");
          return;
        }
        Matches m = new Matches();
        history.add(line);
        String answer;
        if (match3("this is a continuation of talk *", s, m)
          || match3("hello bot! this is a continuation of talk *", s, m)) {
          dialogID = unquote(m.m[0]);
          answer = "ok";
        } else try {
          makeAndroid3_io.set(io);
          answer = makeAndroid3_getAnswer(line, history, a);
        } finally {
          makeAndroid3_io.set(null);
        }
        history.add(answer);
        io.sendLine(answer);
        //appendToLog(logFile, s);
      }
    }
  }};
}

static String makeAndroid3_getAnswer(String line, List<String> history, Android3 a) {
  String answer;
  try {
    answer = makeAndroid3_fallback(line, history, a.responder.answer(line, history));
  } catch (Throwable e) {
    e = getInnerException(e);
    printStackTrace(e);
    answer = e.toString();
  }
  if (!a.incomingSilent)
    print("> " + shorten(answer, 500));
  return answer;
}

static String makeAndroid3_fallback(String s, List<String> history, String answer) {
  // Now we only do the safe thing instead of VM inspection - give out our process ID
  if (answer == null && match3("what is your pid", s))
    return getPID();
    
  if (answer == null && match3("what is your program id", s)) // should be fairly safe, right?
    return getProgramID();
    
  if (match3("get injection id", s))
    return getInjectionID();
    
  if (answer == null) answer = "?";
  if (answer.indexOf('\n') >= 0 || answer.indexOf('\r') >= 0)
    answer = quote(answer);
  return answer;
}

static boolean makeAndroid3_consoleInUse() {
  for (Object o : record_list)
    if (o instanceof Android3 && ((Android3) o).console)
      return true;
  return false;
}

static Responder makeAndroid3_verboseResponder(final Android3 a) {
  return new Responder() {
    String answer(String s, List<String> history) {
      if (a.verbose)
        print("> " + s);
      String answer = a.responder.answer(s, history);
      if (a.verbose)
        print("< " + answer);
      return answer;
    }
  };
}

static ThreadLocal<DialogIO> makeAndroid3_io = new ThreadLocal<DialogIO>();

static int l(Object[] a) { return a == null ? 0 : a.length; }
static int l(boolean[] a) { return a == null ? 0 : a.length; }
static int l(byte[] a) { return a == null ? 0 : a.length; }
static int l(int[] a) { return a == null ? 0 : a.length; }
static int l(float[] a) { return a == null ? 0 : a.length; }
static int l(char[] a) { return a == null ? 0 : a.length; }
static int l(Collection c) { return c == null ? 0 : c.size(); }
static int l(Map m) { return m == null ? 0 : m.size(); }
static int l(CharSequence s) { return s == null ? 0 : s.length(); } 

static int l(Object o) {
  return l((List) o); // incomplete
}



static Object addToMultiPort_responder;

static long addToMultiPort(final String botName) {
  return addToMultiPort(botName, new Object() {
    public String answer(String s, List<String> history) {
      String answer = (String) ( callOpt(getMainClass(), "answer", s, history));
      if (answer != null) return answer;
      answer = (String) callOpt(getMainClass(), "answer", s);
      if (answer != null) return answer;
      if (match3("get injection id", s))
        return getInjectionID();
      return null;
    }
  });
}

static long addToMultiPort(final String botName, final Object responder) {
  print(botName);
  addToMultiPort_responder = responder;
  startMultiPort();
  List ports = getMultiPorts();
  if (ports == null) return 0;
  if (ports.isEmpty())
    throw fail("No multiports!");
  if (ports.size() > 1)
    print("Multiple multi-ports. Using last one.");
  Object port = last(ports);
  Object responder2 = new Object() {
    public String answer(String s, List<String> history) {
      if (match3("get injection id", s))
        return getInjectionID();
      if (match3("your name", s))
        return botName;
      return (String) call(responder, "answer", s, history);
    }
  };
  record(responder2);
  return (Long) call(port, "addResponder", botName, responder2);
}

  // class Matches is added by #752
 
  static boolean match3(String pat, String s) {
    return match3(pat, s, null);
  }
  
  static boolean match3(String pat, String s, Matches matches) {
    if (s == null) return false;
    return match3(pat, parse3(s), matches);
  }
    
  static boolean match3(String pat, List<String> toks, Matches matches) {
    List<String> tokpat = parse3(pat);
    return match3(tokpat,toks,matches);
  }

  static boolean match3(List<String> tokpat, List<String> toks, Matches matches) {

    String[] m = match2(tokpat, toks);
    //print(structure(tokpat) + " on " + structure(toks) + " => " + structure(m));
    if (m == null)
      return false;
    else {
      if (matches != null) matches.m = m;
      return true;
    }
  }
static Object callOpt(Object o) {
  if (o == null) return null;
  return callF(o);
}

static Object callOpt(Object o, String method, Object... args) {
  try {
    if (o == null) return null;
    if (o instanceof Class) {
      Method m = callOpt_findStaticMethod((Class) o, method, args, false);
      if (m == null) return null;
      m.setAccessible(true);
      return m.invoke(null, args);
    } else {
      Method m = callOpt_findMethod(o, method, args, false);
      if (m == null) return null;
      m.setAccessible(true);
      return m.invoke(o, args);
    }
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Method callOpt_findStaticMethod(Class c, String method, Object[] args, boolean debug) {
  Class _c = c;
  while (c != null) {
    for (Method m : c.getDeclaredMethods()) {
      if (debug)
        System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
      if (!m.getName().equals(method)) {
        if (debug) System.out.println("Method name mismatch: " + method);
        continue;
      }

      if ((m.getModifiers() & Modifier.STATIC) == 0 || !callOpt_checkArgs(m, args, debug))
        continue;

      return m;
    }
    c = c.getSuperclass();
  }
  return null;
}

static Method callOpt_findMethod(Object o, String method, Object[] args, boolean debug) {
  Class c = o.getClass();
  while (c != null) {
    for (Method m : c.getDeclaredMethods()) {
      if (debug)
        System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
      if (m.getName().equals(method) && callOpt_checkArgs(m, args, debug))
        return m;
    }
    c = c.getSuperclass();
  }
  return null;
}

private static boolean callOpt_checkArgs(Method m, Object[] args, boolean debug) {
  Class<?>[] types = m.getParameterTypes();
  if (types.length != args.length) {
    if (debug)
      System.out.println("Bad parameter length: " + args.length + " vs " + types.length);
    return false;
  }
  for (int i = 0; i < types.length; i++)
    if (!(args[i] == null || isInstanceX(types[i], args[i]))) {
      if (debug)
        System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
      return false;
    }
  return true;
}


static String programID;

static String getProgramID() {
  return nempty(programID) ? formatSnippetID(programID) : "?";
}

// TODO: ask JavaX instead
static String getProgramID(Class c) {
  String id = (String) getOpt(c, "programID");
  if (nempty(id))
    return formatSnippetID(id);
  return "?";
}

static String getProgramID(Object o) {
  return getProgramID(getMainClass(o));
}
  static String quote(String s) {
    if (s == null) return "null";
    return "\"" + s.replace("\\", "\\\\").replace("\"", "\\\"").replace("\r", "\\r").replace("\n", "\\n") + "\"";
  }
  
  static String quote(long l) {
    return quote("" + l);
  }
  
  static String quote(char c) {
    return quote("" + c);
  }

static String shorten(String s, int max) {
  if (s == null) return "";
  return s.length() <= max ? s : s.substring(0, Math.min(s.length(), max)) + "...";
}
  static AtomicInteger dialogServer_clients = new AtomicInteger();
  static boolean dialogServer_printConnects;
  
  static Set<String> dialogServer_knownClients = synchroTreeSet();
  
  static int startDialogServerOnPortAbove(int port, DialogHandler handler) {
    while (!forbiddenPort(port) && !startDialogServerIfPortAvailable(port, handler))
      ++port;
    return port;
  }
  
  static int startDialogServerOnPortAboveDaemon(int port, DialogHandler handler) {
    while (!forbiddenPort(port) && !startDialogServerIfPortAvailable(port, handler, true))
      ++port;
    return port;
  }
  
  static void startDialogServer(int port, DialogHandler handler) {
    if (!startDialogServerIfPortAvailable(port, handler))
      throw fail("Can't start dialog server on port " + port);
  }
  
  static boolean startDialogServerIfPortAvailable(int port, final DialogHandler handler) {
    return startDialogServerIfPortAvailable(port, handler, false);
  }
  
  static ServerSocket startDialogServer_serverSocket;
    
  static boolean startDialogServerIfPortAvailable(int port, final DialogHandler handler, boolean daemon) {
    ServerSocket serverSocket = null;
    try {
      serverSocket = new ServerSocket(port);
    } catch (IOException e) {
      // probably the port number is used - let's assume there already is a chat server.
      return false;
    }
    final ServerSocket _serverSocket = serverSocket;
    startDialogServer_serverSocket = serverSocket;

    Thread thread = new Thread("Socket accept port " + port) { public void run() {
     try {
      while (true) {
        try {
          final Socket s = _serverSocket.accept();
          
          String client = s.getInetAddress().toString();
          if (!dialogServer_knownClients.contains(client) && neq(client, "/127.0.0.1")) {
            print("connect from " + client + " - clients: " + dialogServer_clients.incrementAndGet());
            dialogServer_knownClients.add(client);
          }
          
          String threadName = "Handling client " + s.getInetAddress();

          Thread t2 = new Thread(threadName) {
           public void run() {
            try {
              final Writer w = new OutputStreamWriter(s.getOutputStream(), "UTF-8");
              final BufferedReader in = new BufferedReader(
                new InputStreamReader(s.getInputStream(), "UTF-8"));
                
              DialogIO io = new DialogIO() {
              
                // This should be the same as #1001076 (talkTo)
              
    boolean isLocalConnection() {
      return s.getInetAddress().isLoopbackAddress();
    }
    
    boolean isStillConnected() {
      return !(eos || s.isClosed());
    }
    
    void sendLine(String line) { try {
 
      w.write(line + "\n");
      w.flush();
    
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
    
    String readLineImpl() { try {
 
      return in.readLine();
    
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
    
    void close() {
      try {
        s.close();
      } catch (IOException e) {
        // whatever
      }
    }
    
    Socket getSocket() {
      return s;
    }
    };
              
              try {
                handler.run(io);
              } finally {
                s.close();
              }
            } catch (IOException e) {
              print("[internal] " + e);
            } finally {
              //print("client disconnect - " + dialogServer_clients.decrementAndGet() + " remaining");
            }
           }
          }; // Thread t2
          t2.setDaemon(true); // ?
          t2.start();
        } catch (SocketTimeoutException e) {
        }
      }   
     } catch (IOException e) {
       print("[internal] " + e);
     }
    }};
    if (daemon) thread.setDaemon(true);
    thread.start();
   
    print("Dialog server on port " + port + " started."); 
    return true;
  }
static boolean publicCommOn() {
  return "1".equals(loadTextFile(new File(userHome(), ".javax/public-communication")));
}
static List<Object> record_list = synchroList();

static void record(Object o) {
  record_list.add(o);
}
static long now_virtualTime;
static long now() {
  return now_virtualTime != 0 ? now_virtualTime : System.currentTimeMillis();
}

// try to get our current process ID
static String getPID() {
  String name = ManagementFactory.getRuntimeMXBean().getName();
  return name.replaceAll("@.*", "");
}
  public static String unquote(String s) {
    if (s == null) return null;
    if (s.startsWith("[")) {
      int i = 1;
      while (i < s.length() && s.charAt(i) == '=') ++i;
      if (i < s.length() && s.charAt(i) == '[') {
        String m = s.substring(1, i);
        if (s.endsWith("]" + m + "]"))
          return s.substring(i+1, s.length()-i-1);
      }
    }
    
    if (s.startsWith("\"") /*&& s.endsWith("\"")*/ && s.length() > 1) {
      String st = s.substring(1, s.endsWith("\"") ? s.length()-1 : s.length());
      StringBuilder sb = new StringBuilder(st.length());
  
      for (int i = 0; i < st.length(); i++) {
        char ch = st.charAt(i);
        if (ch == '\\') {
          char nextChar = (i == st.length() - 1) ? '\\' : st
                  .charAt(i + 1);
          // Octal escape?
          if (nextChar >= '0' && nextChar <= '7') {
              String code = "" + nextChar;
              i++;
              if ((i < st.length() - 1) && st.charAt(i + 1) >= '0'
                      && st.charAt(i + 1) <= '7') {
                  code += st.charAt(i + 1);
                  i++;
                  if ((i < st.length() - 1) && st.charAt(i + 1) >= '0'
                          && st.charAt(i + 1) <= '7') {
                      code += st.charAt(i + 1);
                      i++;
                  }
              }
              sb.append((char) Integer.parseInt(code, 8));
              continue;
          }
          switch (nextChar) {
          case '\\':
              ch = '\\';
              break;
          case 'b':
              ch = '\b';
              break;
          case 'f':
              ch = '\f';
              break;
          case 'n':
              ch = '\n';
              break;
          case 'r':
              ch = '\r';
              break;
          case 't':
              ch = '\t';
              break;
          case '\"':
              ch = '\"';
              break;
          case '\'':
              ch = '\'';
              break;
          // Hex Unicode: u????
          case 'u':
              if (i >= st.length() - 5) {
                  ch = 'u';
                  break;
              }
              int code = Integer.parseInt(
                      "" + st.charAt(i + 2) + st.charAt(i + 3)
                              + st.charAt(i + 4) + st.charAt(i + 5), 16);
              sb.append(Character.toChars(code));
              i += 5;
              continue;
          default:
            ch = nextChar; // added by Stefan
          }
          i++;
        }
        sb.append(ch);
      }
      return sb.toString();      
    } else
      return s; // return original
  }
static void printStackTrace(Throwable e) {
  // we go to system.out now - system.err is nonsense
  print(getStackTrace(e));
}

static void printStackTrace() {
  printStackTrace(new Throwable());
}
static String callStaticAnswerMethod(List bots, String s) {
  for (Object c : bots) try {
    String answer = callStaticAnswerMethod(c, s);
    if (!empty(answer)) return answer;
  } catch (Throwable e) {
    print("Error calling " + getProgramID(c));
    e.printStackTrace();
  }
  return null;
}

static String callStaticAnswerMethod(Object c, String s) {
  String answer = (String) callOpt(c, "answer", s, litlist(s));
  if (answer == null)
    answer = (String) callOpt(c, "answer", s);
  return emptyToNull(answer);
}

static String callStaticAnswerMethod(String s, List<String> history) {
  String answer = (String) callOpt(mc(), "answer", s, history);
  if (answer == null)
    answer = (String) callOpt(mc(), "answer", s);
  return emptyToNull(answer);
}
static String getInjectionID() {
  return (String) call(getJavaX(), "getInjectionID", getMainClass());
}
static BufferedReader readLine_reader;

static String readLine() {
  return (String) call(getJavaX(), "readLine");
}
static boolean eq(Object a, Object b) {
  if (a == null) return b == null;
  if (a.equals(b)) return true;
  if (a instanceof BigInteger) {
    if (b instanceof Integer) return a.equals(BigInteger.valueOf((Integer) b));
    if (b instanceof Long) return a.equals(BigInteger.valueOf((Long) b));
  }
  return false;
}
static void removeFromMultiPort(long vport) {
  for (Object port : getMultiPorts())
    call(port, "removePort", vport);
}
static Throwable getInnerException(Throwable e) {
  while (e.getCause() != null)
    e = e.getCause();
  return e;
}
static volatile StringBuffer local_log = new StringBuffer(); // not redirected
static volatile StringBuffer print_log = local_log; // might be redirected, e.g. to main bot

// in bytes - will cut to half that
static volatile int print_log_max = 1024*1024;
static volatile int local_log_max = 100*1024;
//static int print_maxLineLength = 0; // 0 = unset

static boolean print_silent; // total mute if set

static void print() {
  print("");
}

// slightly overblown signature to return original object...
static <A> A print(A o) {
  if (print_silent) return o;
  String s = String.valueOf(o) + "\n";
  // TODO if (print_maxLineLength != 0)
  StringBuffer loc = local_log;
  StringBuffer buf = print_log;
  int loc_max = print_log_max;
  if (buf != loc && buf != null) {
    print_append(buf, s, print_log_max);
    loc_max = local_log_max;
  }
  if (loc != null) 
    print_append(loc, s, loc_max);
  System.out.print(s);
  return o;
}

static void print(long l) {
  print(String.valueOf(l));
}

static void print(char c) {
  print(String.valueOf(c));
}

static void print_append(StringBuffer buf, String s, int max) {
  synchronized(buf) {
    buf.append(s);
    max /= 2;
    if (buf.length() > max) try {
      int newLength = max/2;
      int ofs = buf.length()-newLength;
      String newString = buf.substring(ofs);
      buf.setLength(0);
      buf.append("[...] ").append(newString);
    } catch (Exception e) {
      buf.setLength(0);
    }
  }
}
static int randomID_defaultLength = 12;

static String randomID(int length) {
  return makeRandomID(length);
}

static String randomID() {
  return randomID(randomID_defaultLength);
}


// match2 matches multiple "*" (matches a single token) wildcards and zero or one "..." wildcards (matches multiple tokens)

static String[] match2(List<String> pat, List<String> tok) {
  // standard case (no ...)
  int i = pat.indexOf("...");
  if (i < 0) return match2_match(pat, tok);
  
  pat = new ArrayList<String>(pat); // We're modifying it, so copy first
  pat.set(i, "*");
  while (pat.size() < tok.size()) {
    pat.add(i, "*");
    pat.add(i+1, ""); // doesn't matter
  }
  
  return match2_match(pat, tok);
}

static String[] match2_match(List<String> pat, List<String> tok) {
  List<String> result = new ArrayList<String>();
  if (pat.size() != tok.size()) {
    /*if (debug)
      print("Size mismatch: " + structure(pat) + " vs " + structure(tok));*/
    return null;
  }
  for (int i = 1; i < pat.size(); i += 2) {
    String p = pat.get(i), t = tok.get(i);
    /*if (debug)
      print("Checking " + p + " against " + t);*/
    if (eq(p, "*"))
      result.add(t);
    else if (!equalsIgnoreCase(unquote(p), unquote(t))) // bold change - match quoted and unquoted now
      return null;
  }
  return result.toArray(new String[result.size()]);
}

static Object callF(Object f, Object... args) {
  return callFunction(f, args);
}
static boolean empty(Collection c) {
  return isEmpty(c);
}

static boolean empty(String s) {
  return isEmpty(s);
}

static boolean empty(Map map) {
  return map == null || map.isEmpty();
}

static boolean empty(Object[] o) {
  return o == null || o.length == 0;
}

static boolean empty(Object o) {
  if (o instanceof Collection) return empty((Collection) o);
  if (o instanceof String) return empty((String) o);
  if (o instanceof Map) return empty((Map) o);
  if (o instanceof Object[]) return empty((Object[]) o);
  throw fail("unknown type for 'empty': " + getType(o));
}
static String getStackTrace(Throwable throwable) {
  StringWriter writer = new StringWriter();
  throwable.printStackTrace(new PrintWriter(writer));
  return writer.toString();
}
static Object mc() {
  return getMainClass();
}
static String formatSnippetID(String id) {
  return "#" + parseSnippetID(id);
}

static String formatSnippetID(long id) {
  return "#" + id;
}
static boolean neq(Object a, Object b) {
  return !eq(a, b);
}
// extended over Class.isInstance() to handle primitive types
static boolean isInstanceX(Class type, Object arg) {
  if (type == boolean.class) return arg instanceof Boolean;
  if (type == int.class) return arg instanceof Integer;
  if (type == long.class) return arg instanceof Long;
  if (type == float.class) return arg instanceof Float;
  if (type == short.class) return arg instanceof Short;
  if (type == char.class) return arg instanceof Character;
  if (type == byte.class) return arg instanceof Byte;
  if (type == double.class) return arg instanceof Double;
  return type.isInstance(arg);
}
static <A> A last(List<A> l) {
  return l.isEmpty() ? null : l.get(l.size()-1);
}

static char last(String s) {
  return empty(s) ? '#' : s.charAt(l(s)-1);
}
static List<Object> getMultiPorts() {
  return (List) callOpt(getJavaX(), "getMultiPorts");
}
static String emptyToNull(String s) {
  return eq(s, "") ? null : s;
}
static boolean forbiddenPort(int port) {
  return port == 5037; // adb
}

  static RuntimeException fail() {
    throw new RuntimeException("fail");
  }
  
  static RuntimeException fail(Object msg) {
    throw new RuntimeException(String.valueOf(msg));
  }
  
  static RuntimeException fail(String msg) {
    throw new RuntimeException(unnull(msg));
  }
   
  // disabled for now to shorten some programs 
  /*static RuntimeException fail(S msg, O... args) {
    throw new RuntimeException(format(msg, args));
  }*/
static <A> Set<A> synchroTreeSet() {
  return Collections.synchronizedSet(new TreeSet<A>());
}

  static List<String> parse3(String s) {
    return dropPunctuation(javaTokPlusPeriod(s));
  }
static String _userHome;
static String userHome() {
  if (_userHome == null) {
    if (isAndroid())
      _userHome = "/storage/sdcard0/";
    else
      _userHome = System.getProperty("user.home");
    //System.out.println("userHome: " + _userHome);
  }
  return _userHome;
}

static File userHome(String path) {
  return new File(userDir(), path);
}
static <A> ArrayList<A> litlist(A... a) {
  return new ArrayList<A>(Arrays.asList(a));
}
static <A> List<A> synchroList() {
  return Collections.synchronizedList(new ArrayList<A>());
}

static <A> List<A> synchroList(List<A> l) {
  return Collections.synchronizedList(l);
}

static Class getMainClass() { try {
 
  return Class.forName("main");

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}

static Class getMainClass(Object o) { try {
 
  return (o instanceof Class ? (Class) o : o.getClass()).getClassLoader().loadClass("main");

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static Class __javax;

static Class getJavaX() {
  return __javax;
}
  public static String loadTextFile(String fileName) {
    try {
      return loadTextFile(fileName, null);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
  
  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(File fileName) {
    try {
      return loadTextFile(fileName, null);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static String loadTextFile(File fileName, String defaultContents) throws IOException {
    try {
      return loadTextFile(fileName.getPath(), defaultContents);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
  
  public static String loadTextFile(Reader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    try {
      char[] buffer = new char[1024];
      int n;
      while (-1 != (n = reader.read(buffer)))
        builder.append(buffer, 0, n);
        
    } finally {
      reader.close();
    }
    return builder.toString();
  }
static boolean nempty(Collection c) {
  return !isEmpty(c);
}

static boolean nempty(CharSequence s) {
  return !isEmpty(s);
}

static boolean nempty(Object[] o) {
  return !isEmpty(o);
}

static boolean nempty(Map m) {
  return !isEmpty(m);
}

static boolean nempty(Iterator i) {
  return i != null && i.hasNext();
}
static String makeRandomID(int length) {
  Random random = new Random();
  char[] id = new char[length];
  for (int i = 0; i < id.length; i++)
    id[i] = (char) ((int) 'a' + random.nextInt(26));
  return new String(id);
}
  static Object call(Object o) {
    return callFunction(o);
  }
  
  // varargs assignment fixer for a single string array argument
  static Object call(Object o, String method, String[] arg) {
    return call(o, method, new Object[] {arg});
  }
  
  static Object call(Object o, String method, Object... args) {
    try {
      if (o instanceof Class) {
        Method m = call_findStaticMethod((Class) o, method, args, false);
        m.setAccessible(true);
        return m.invoke(null, args);
      } else {
        Method m = call_findMethod(o, method, args, false);
        m.setAccessible(true);
        return m.invoke(o, args);
      }
    } catch (Exception e) {
      throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
    }
  }

  static Method call_findStaticMethod(Class c, String method, Object[] args, boolean debug) {
    Class _c = c;
    while (c != null) {
      for (Method m : c.getDeclaredMethods()) {
        if (debug)
          System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
        if (!m.getName().equals(method)) {
          if (debug) System.out.println("Method name mismatch: " + method);
          continue;
        }

        if ((m.getModifiers() & Modifier.STATIC) == 0 || !call_checkArgs(m, args, debug))
          continue;

        return m;
      }
      c = c.getSuperclass();
    }
    throw new RuntimeException("Method '" + method + "' (static) with " + args.length + " parameter(s) not found in " + _c.getName());
  }

  static Method call_findMethod(Object o, String method, Object[] args, boolean debug) {
    Class c = o.getClass();
    while (c != null) {
      for (Method m : c.getDeclaredMethods()) {
        if (debug)
          System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
        if (m.getName().equals(method) && call_checkArgs(m, args, debug))
          return m;
      }
      c = c.getSuperclass();
    }
    throw new RuntimeException("Method '" + method + "' (non-static) with " + args.length + " parameter(s) not found in " + o.getClass().getName());
  }

  private static boolean call_checkArgs(Method m, Object[] args, boolean debug) {
    Class<?>[] types = m.getParameterTypes();
    if (types.length != args.length) {
      if (debug)
        System.out.println("Bad parameter length: " + args.length + " vs " + types.length);
      return false;
    }
    for (int i = 0; i < types.length; i++)
      if (!(args[i] == null || isInstanceX(types[i], args[i]))) {
        if (debug)
          System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
        return false;
      }
    return true;
  }


static Object getOpt(Object o, String field) {
  if (o instanceof String) o = getBot ((String) o);
  if (o == null) return null;
  if (o instanceof Class) return getOpt((Class) o, field);
  
  if (o.getClass().getName().equals("main$DynamicObject"))
    return ((Map) getOpt_raw(o, "fieldValues")).get(field);
  
  if (o instanceof Map) return ((Map) o).get(field);
  
  return getOpt_raw(o, field);
}

static Object getOpt_raw(Object o, String field) {
  try {
    Field f = getOpt_findField(o.getClass(), field);
    if (f == null) return null;
    f.setAccessible(true);
    return f.get(o);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Object getOpt(Class c, String field) {
  try {
    if (c == null) return null;
    Field f = getOpt_findStaticField(c, field);
    if (f == null) return null;
    f.setAccessible(true);
    return f.get(null);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Field getOpt_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}

static Field getOpt_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}
// start multi-port if none exists in current VM.
static void startMultiPort() {
  List mp = getMultiPorts();
  if (mp != null && mp.isEmpty())
    callMain(hotwire("#1001672"));
}


static void callMain(Object c, String... args) {
  callOpt(c, "main", new Object[] {args});
}
static Object callFunction(Object f, Object... args) {
  if (f == null) return null;
  if (f instanceof Runnable) {
    ((Runnable) f).run();
    return null;
  } else if (f instanceof String)
    return call(mc(), (String) f, args);
  else
    return call(f, "get", args);
  //else throw fail("Can't call a " + getClassName(f));
}
static Object getBot(String botID) {
  return callOpt(getMainBot(), "getBot", botID);
}

static boolean equalsIgnoreCase(String a, String b) {
  return a == null ? b == null : a.equalsIgnoreCase(b);
}
static String getType(Object o) {
  return getClassName(o);
}
// This is made for NL parsing.
// It's javaTok extended with "..." token, "$n" and "#n" and
// special quotes (which are converted to normal ones).

static List<String> javaTokPlusPeriod(String s) {
  List<String> tok = new ArrayList<String>();
  int l = s.length();
  
  int i = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    tok.add(s.substring(i, j));
    i = j;
    if (i >= l) break;
    c = s.charAt(i);
    cc = s.substring(i, Math.min(i+2, l));

    // scan for non-whitespace
    if (c == '\u201C' || c == '\u201D') c = '"'; // normalize quotes
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        char _c = s.charAt(j);
        if (_c == '\u201C' || _c == '\u201D') _c = '"'; // normalize quotes
        if (_c == opener) {
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
      if (j-1 >= i+1) {
        tok.add(opener + s.substring(i+1, j-1) + opener);
        i = j;
        continue;
      }
    } else if (Character.isJavaIdentifierStart(c))
      do ++j; while (j < l && (Character.isJavaIdentifierPart(s.charAt(j)) || s.charAt(j) == '\'')); // for things like "this one's"
    else if (Character.isDigit(c))
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
    else if (cc.equals("[[")) {
      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));
      j = Math.min(j+2, l);
    } else if (cc.equals("[=") && i+2 < l && s.charAt(i+2) == '[') {
      do ++j; while (j+2 < l && !s.substring(j, j+3).equals("]=]"));
      j = Math.min(j+3, l);
    } else if (s.substring(j, Math.min(j+3, l)).equals("..."))
      j += 3;
    else if (c == '$' || c == '#')
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
    else
      ++j;

    tok.add(s.substring(i, j));
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  return tok;
}


  static String unnull(String s) {
    return s == null ? "" : s;
  }
  
  static <A> List<A> unnull(List<A> l) {
    return l == null ? emptyList() : l;
  }
  
  static <A> Iterable<A> unnull(Iterable<A> i) {
    return i == null ? emptyList() : i;
  }
  
  static Object[] unnull(Object[] a) {
    return a == null ? new Object[0] : a;
  }
public static long parseSnippetID(String snippetID) {
  long id = Long.parseLong(shortenSnippetID(snippetID));
  if (id == 0) throw fail("0 is not a snippet ID");
  return id;
}
  // compile JavaX source, load classes & return main class
  // src can be a snippet ID or actual source code
  // TODO: record injection?
  
  static Class<?> hotwire(String src) {
    try {
      Class j = getJavaX();
      
      synchronized(j) { // hopefully this goes well...
        List<File> libraries = new ArrayList<File>();
        File srcDir = (File) call(j, "transpileMain", src, libraries);
        if (srcDir == null)
          throw fail("transpileMain returned null (src=" + quote(src) + ")");
        
        Object androidContext = get(j, "androidContext");
        if (androidContext != null)
          return (Class) call(j, "loadx2android", srcDir, src);
          
        File classesDir = (File) call(j, "TempDirMaker_make");
        String javacOutput = (String) call(j, "compileJava", srcDir, libraries, classesDir);
        System.out.println(javacOutput);
        
        URL[] urls = new URL[libraries.size()+1];
        urls[0] = classesDir.toURI().toURL();
        for (int i = 0; i < libraries.size(); i++)
          urls[i+1] = libraries.get(i).toURI().toURL();
  
        // make class loader
        URLClassLoader classLoader = new URLClassLoader(urls);
    
        // load & return main class
        Class<?> theClass = classLoader.loadClass("main");
        
        callOpt(j, "registerSourceCode", theClass, loadTextFile(new File(srcDir, "main.java")));

        call(j, "setVars", theClass, isSnippetID(src) ? src: null);
        
        if (isSnippetID(src))
          callOpt(j, "addInstance", src, theClass);
          
        if (!_inCore())
          hotwire_copyOver(theClass);
  
        return theClass;
      }
    } catch (Exception e) {
      throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
    }
  }
static List<String> dropPunctuation_keep = litlist("*", "<", ">");

static List<String> dropPunctuation(List<String> tok) {
  tok = new ArrayList<String>(tok);
  for (int i = 1; i < tok.size(); i += 2) {
    String t = tok.get(i);
    if (t.length() == 1 && !Character.isLetter(t.charAt(0)) && !Character.isDigit(t.charAt(0)) && !dropPunctuation_keep.contains(t)) {
      tok.set(i-1, tok.get(i-1) + tok.get(i+1));
      tok.remove(i);
      tok.remove(i);
      i -= 2;
    }
  }
  return tok;
}

static String dropPunctuation(String s) {
  return join(dropPunctuation(nlTok(s)));
}
static boolean isEmpty(Collection c) {
  return c == null || c.isEmpty();
}

static boolean isEmpty(CharSequence s) {
  return s == null || s.length() == 0;
}

static boolean isEmpty(Object[] a) {
  return a == null || a.length == 0;
}

static boolean isEmpty(Map map) {
  return map == null || map.isEmpty();
}
static File userDir() {
  return new File(userHome());
}

static File userDir(String path) {
  return new File(userHome(), path);
}
static boolean isAndroid() { return System.getProperty("java.vendor").toLowerCase().indexOf("android") >= 0; }


static void hotwire_copyOver(Class c) {
  synchronized(StringBuffer.class) {
    for (String field : litlist("print_log", "print_silent", "androidContext")) {
      Object o = getOpt(mc(), field);
      if (o != null)
        setOpt(c, field, o);
    }
      
    Object mainBot = getMainBot();
    if (mainBot != null)
      setOpt(c, "mainBot", mainBot);

    setOpt(c, "creator_class", new WeakReference(mc()));
  }
}
  public static String join(String glue, Iterable<String> strings) {
    StringBuilder buf = new StringBuilder();
    Iterator<String> i = strings.iterator();
    if (i.hasNext()) {
      buf.append(i.next());
      while (i.hasNext())
        buf.append(glue).append(i.next());
    }
    return buf.toString();
  }
  
  public static String join(String glue, String[] strings) {
    return join(glue, Arrays.asList(strings));
  }
  
  public static String join(Iterable<String> strings) {
    return join("", strings);
  }
  
  public static String join(String[] strings) {
    return join("", strings);
  }

static String shortenSnippetID(String snippetID) {
  if (snippetID.startsWith("#"))
    snippetID = snippetID.substring(1);
  String httpBlaBla = "http://tinybrain.de/";
  if (snippetID.startsWith(httpBlaBla))
    snippetID = snippetID.substring(httpBlaBla.length());
  return "" + parseLong(snippetID);
}
static String getClassName(Object o) {
  return o == null ? "null" : o.getClass().getName();
}
static boolean _inCore() {
  return false;
}
static Object mainBot;

static Object getMainBot() {
  return mainBot;
}
  public static boolean isSnippetID(String s) {
    try {
      parseSnippetID(s);
      return true;
    } catch (RuntimeException e) {
      return false;
    }
  }
static List emptyList() {
  return new ArrayList();
  //ret Collections.emptyList();
}
// get purpose 1: access a list/array (safer version of x.get(y))

static <A> A get(List<A> l, int idx) {
  return idx >= 0 && idx < l(l) ? l.get(idx) : null;
}

static <A> A get(A[] l, int idx) {
  return idx >= 0 && idx < l(l) ? l[idx] : null;
}

// default to false
static boolean get(boolean[] l, int idx) {
  return idx >= 0 && idx < l(l) ? l[idx] : false;
}

static Class get_dynamicObject = findClass("DynamicObject");

// get purpose 2: access a field by reflection or a map

static Object get(Object o, String field) {
  try {
    if (o instanceof Class) return get((Class) o, field);
    
    if (o instanceof Map)
      return ((Map) o).get(field);
      
    Field f = getOpt_findField(o.getClass(), field);
    if (f != null) {
      f.setAccessible(true);
      return f.get(o);
    }
      
    if (get_dynamicObject != null && get_dynamicObject.isInstance(o))
      return call(get_raw(o, "fieldValues"), "get", field);
  } catch (Exception e) {
    throw asRuntimeException(e);
  }
  throw new RuntimeException("Field '" + field + "' not found in " + o.getClass().getName());
}

static Object get_raw(Object o, String field) {
  try {
    Field f = get_findField(o.getClass(), field);
    f.setAccessible(true);
    return f.get(o);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Object get(Class c, String field) {
  try {
    Field f = get_findStaticField(c, field);
    f.setAccessible(true);
    return f.get(null);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Field get_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
}

static Field get_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Field '" + field + "' not found in " + c.getName());
}
static List<String> nlTok(String s) {
  return javaTokPlusPeriod(s);
}


static RuntimeException asRuntimeException(Throwable t) {
  return t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
}
// currently finds only inner classes of class "main"
// returns null on not found
// this is the simple version that is not case-tolerant
static Class findClass(String name) {
  if (!isJavaIdentifier(name)) return null;
  try {
    return Class.forName("main$" + name);
  } catch (ClassNotFoundException e) {
    return null;
  }
}
static void setOpt(Object o, String field, Object value) {
  if (o instanceof Class) setOpt((Class) o, field, value);
  else try {
    Field f = setOpt_findField(o.getClass(), field);
    if (f != null)
      smartSet(f, o, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static void setOpt(Class c, String field, Object value) {
  try {
    Field f = setOpt_findStaticField(c, field);
    if (f != null)
      smartSet(f, null, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}
  
static Field setOpt_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}

static Field setOpt_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}
static long parseLong(String s) {
  if (s == null) return 0;
  return Long.parseLong(dropSuffix("L", s));
}

static long parseLong(Object s) {
  return Long.parseLong((String) s);
}


static boolean isJavaIdentifier(String s) {
  if (s.length() == 0 || !Character.isJavaIdentifierStart(s.charAt(0)))
    return false;
  for (int i = 1; i < s.length(); i++)
    if (!Character.isJavaIdentifierPart(s.charAt(i)))
      return false;
  return true;
}
static String dropSuffix(String suffix, String s) {
  return s.endsWith(suffix) ? s.substring(0, l(s)-l(suffix)) : s;
}
static void smartSet(Field f, Object o, Object value) throws Exception {
  f.setAccessible(true);
  
  // take care of common case (long to int)
  if (f.getType() == int.class && value instanceof Long)
    value = ((Long) value).intValue();
    
  f.set(o, value);
}


  static abstract class DialogIO {
    String line;
    boolean eos, loud;
    
    abstract String readLineImpl();
    abstract boolean isStillConnected();
    abstract void sendLine(String line);
    abstract boolean isLocalConnection();
    abstract Socket getSocket();
    abstract void close();
    
    int getPort() { return getSocket().getPort(); }
    
    boolean helloRead;
    
    String readLineNoBlock() {
      String l = line;
      line = null;
      return l;
    }
    
    boolean waitForLine() { try {
 
      if (line != null) return true;
      //print("Readline");
      line = readLineImpl();
      //print("Readline done: " + line);
      if (line == null) eos = true;
      return line != null;
    
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
    
    String readLine() {
      waitForLine();
      helloRead = true;
      return readLineNoBlock();
    }
    
    String ask(String s, Object... args) {
      if (loud) return askLoudly(s, args);
      if (!helloRead) readLine();
      if (args.length != 0) s = format3(s, args);
      sendLine(s);
      return readLine();
    }
    
    String askLoudly(String s, Object... args) {
      if (!helloRead) readLine();
      if (args.length != 0) s = format3(s, args);
      print("> " + s);
      sendLine(s);
      String answer = readLine();
      print("< " + answer);
      return answer;
    }
    
    void pushback(String l) {
      if (line != null)
        throw fail();
      line = l;
      helloRead = false;
    }
  }
  
  static abstract class DialogHandler {
    abstract void run(DialogIO io);
  }

  static class Matches {
    String[] m;
    String get(int i) { return i < m.length ? m[i] : null; }
    String unq(int i) { return unquote(get(i)); }
    String fsi(int i) { return formatSnippetID(unq(i)); }
    String fsi() { return fsi(0); }
    String tlc(int i) { return unq(i).toLowerCase(); }
    boolean bool(int i) { return "true".equals(unq(i)); }
    String rest() { return m[m.length-1]; } // for matchStart
    int psi(int i) { return Integer.parseInt(unq(i)); }
  }


  static String format3(String pat, Object... args) {
    if (args.length == 0) return pat;
    
    List<String> tok = javaTokPlusPeriod(pat);
    int argidx = 0;
    for (int i = 1; i < tok.size(); i += 2)
      if (tok.get(i).equals("*"))
        tok.set(i, format3_formatArg(argidx < args.length ? args[argidx++] : "null"));
    return join(tok);
  }
  
  static String format3_formatArg(Object arg) {
    if (arg == null) return "null";
    if (arg instanceof String) {
      String s = (String) arg;
      return isIdentifier(s) || isNonNegativeInteger(s) ? s : quote(s);
    }
    if (arg instanceof Integer || arg instanceof Long) return String.valueOf(arg);
    return quote(structure(arg));
  }
  

static String fsi(String id) {
  return formatSnippetID(id);
}


static boolean isIdentifier(String s) {
  return isJavaIdentifier(s);
}
static boolean isNonNegativeInteger(String s) {
  return s != null && Pattern.matches("\\d+", s);
}
static String structure(Object o) {
  HashSet refd = new HashSet();
  return structure_2(structure_1(o, new structure_Data(refd)), refd);
}

// leave to false, unless unstructure() breaks
static boolean structure_allowShortening = false;

static int structure_shareStringsLongerThan = 20;

static class structure_Data {
  int stringSizeLimit;
  IdentityHashMap<Object, Integer> seen = new IdentityHashMap<Object, Integer>();
  HashSet<Integer> refd;
  HashMap<String, Integer> strings = new HashMap<String, Integer>();
  HashSet<String> concepts = new HashSet<String>();
  Class conceptClass = findClass("Concept");
  
  structure_Data(HashSet<Integer> refd) {
  this.refd = refd;}
}

static String structure_1(Object o, structure_Data d) {
  if (o == null) return "null";
  
  // these are never back-referenced (for readability)
  
  if (o instanceof BigInteger)
    return "bigint(" + o + ")";
  
  if (o instanceof Double)
    return "d(" + quote(str(o)) + ")";
    
  if (o instanceof Float)
    return "fl " + quote(str(o));
    
  if (o instanceof Long)
    return o + "L";
  
  if (o instanceof Integer)
    return str(o);
    
  if (o instanceof Boolean)
    return ((Boolean) o).booleanValue() ? "t" : "f";
    
  if (o instanceof Character)
    return quoteCharacter((Character) o);
    
  if (o instanceof File)
    return "File " + quote(((File) o).getPath());
    
  // referencable objects follow
  
  Integer ref = d.seen.get(o);
  if (ref != null) {
    d.refd.add(ref);
    return "r" + ref;
  }
      
  if (o instanceof String && (ref = d.strings.get((String) o)) != null) {
    d.refd.add(ref);
    return "r" + ref;
  }
  
  ref = d.seen.size()+1;
  d.seen.put(o, ref);
  String r = "m" + ref + " "; // marker

  if (o instanceof String) {
    String s = d.stringSizeLimit != 0 ? shorten((String) o, d.stringSizeLimit) : (String) o;
    if (l(s) >= structure_shareStringsLongerThan)
      d.strings.put(s, ref);
    return r + quote(s);
  }
    
  String name = o.getClass().getName();

  StringBuilder buf = new StringBuilder();
  
  if (o instanceof HashSet)
    return r + "hashset " + structure_1(new ArrayList((Set) o), d);

  if (o instanceof TreeSet)
    return r + "treeset " + structure_1(new ArrayList((Set) o), d);
  
  if (o instanceof Collection) {
    for (Object x : (Collection) o) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(x, d));
    }
    return r + "[" + buf + "]";
  }
  
  if (o instanceof Map) {
    for (Object e : ((Map) o).entrySet()) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(((Map.Entry) e).getKey(), d));
      buf.append("=");
      buf.append(structure_1(((Map.Entry) e).getValue(), d));
    }
    return r + (o instanceof HashMap ? "hm" : "") + "{" + buf + "}";
  }
  
  if (o.getClass().isArray()) {
    if (o instanceof byte[])
      return "ba " + quote(bytesToHex((byte[]) o));

    int n = Array.getLength(o);

    if (o instanceof boolean[]) {
      String hex = boolArrayToHex((boolean[]) o);
      int i = l(hex);
      while (i > 0 && hex.charAt(i-1) == '0' && hex.charAt(i-2) == '0') i -= 2;
      return "boolarray " + n + " " + quote(substring(hex, 0, i));
    }
    
    String atype = "array", sep = ", ";

    if (o instanceof int[]) {
      //ret "intarray " + quote(intArrayToHex((int[]) o));
      atype = "intarray";
      sep = " ";
    }

    for (int i = 0; i < n; i++) {
      if (buf.length() != 0) buf.append(sep);
      buf.append(structure_1(Array.get(o, i), d));
    }
    return r + atype + "{" + buf + "}";
  }

  if (o instanceof Class)
    return r + "class(" + quote(((Class) o).getName()) + ")";
    
  if (o instanceof Throwable)
    return r + "exception(" + quote(((Throwable) o).getMessage()) + ")";
    
  if (o instanceof BitSet) {
    BitSet bs = (BitSet) o;
    for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
      if (buf.length() != 0) buf.append(", ");
       buf.append(i);
    }
    return "bitset{" + buf + "}";
  }
    
  // Need more cases? This should cover all library classes...
  if (name.startsWith("java.") || name.startsWith("javax."))
    return r + String.valueOf(o);
    
  String shortName = o.getClass().getName().replaceAll("^main\\$", "");
  
  if (shortName.equals("Lisp")) {
    buf.append("l(" + structure_1(getOpt(o, "head"), d));
    List args = (List) ( getOpt(o, "args"));
    if (nempty(args))
      for (int i = 0; i < l(args); i++) {
        buf.append(", ");
        Object arg = args.get(i);
        
        // sweet shortening
        if (arg != null && eq(arg.getClass().getName(), "main$Lisp") && isTrue(call(arg, "isEmpty")))
          arg = get(arg, "head");
          
        buf.append(structure_1(arg, d));
      }
    buf.append(")");
    return r + str(buf);
  }
    
  int numFields = 0;
  String fieldName = "";
  if (shortName.equals("DynamicObject")) {
    shortName = (String) get_raw(o, "className");
    Map<String, Object> fieldValues = (Map) get_raw(o, "fieldValues");
    
    for (String _fieldName : fieldValues.keySet()) {
      fieldName = _fieldName;
      Object value = fieldValues.get(fieldName);
      if (value != null) {
        if (buf.length() != 0) buf.append(", ");
        buf.append(fieldName + "=" + structure_1(value, d));
      }
      ++numFields;
   }
  } else {
    // regular class
    
    Class c = o.getClass();
    
    if (d.conceptClass != null && d.conceptClass.isInstance(o) && !d.concepts.contains(c.getName())) {
      d.concepts.add(c.getName());
      r += "c ";
    }
    
    while (c != Object.class) {
      List<Field> fields = asList(c.getDeclaredFields());
      for (int i = 1; i < l(fields); i++)
        if (eq(fields.get(i).getName(), "this$1")) {
          swapElements(fields, 0, i);
          break;
        }
      for (Field field : fields) {
        if ((field.getModifiers() & (Modifier.STATIC | Modifier.TRANSIENT)) != 0)
          continue;
        fieldName = field.getName();
        
        // skip outer object reference
        //if (fieldName.indexOf("$") >= 0) continue;
  
        Object value;
        try {
          field.setAccessible(true);
          value = field.get(o);
        } catch (Exception e) {
          value = "?";
        }
        
        // put special cases here...
    
        if (value != null) {
          if (buf.length() != 0) buf.append(", ");
          buf.append(fieldName + "=" + structure_1(value, d));
        }
        ++numFields;
      }
      c = c.getSuperclass();
    }
  }
  
  String b = buf.toString();
  
  if (numFields == 1 && structure_allowShortening)
    b = b.replaceAll("^" + fieldName + "=", ""); // drop field name if only one
  String s = shortName;
  if (buf.length() != 0)
    s += "(" + b + ")";
  return r + s;
}

// drop unused markers
static String structure_2(String s, HashSet<Integer> refd) {
  List<String> tok = javaTok(s);
  StringBuilder out = new StringBuilder();
  for (int i = 1; i < l(tok); i += 2) {
    String t = tok.get(i);
    if (t.startsWith("m") && isInteger(t.substring(1))
      && !refd.contains(parseInt(t.substring(1))))
      continue;
    out.append(t).append(tok.get(i+1));
  }
  return str(out);
}



static <A> ArrayList<A> asList(A[] a) {
  return new ArrayList<A>(Arrays.asList(a));
}

static ArrayList<Integer> asList(int[] a) {
  ArrayList<Integer> l = new ArrayList();
  for (int i : a) l.add(i);
  return l;
}

static <A> ArrayList<A> asList(Iterable<A> s) {
  if (s instanceof ArrayList) return (ArrayList) s;
  ArrayList l = new ArrayList();
  if (s != null)
    for (A a : s)
      l.add(a);
  return l;
}
static String quoteCharacter(char c) {
  if (c == '\'') return "'\\''";
  if (c == '\\') return "'\\\\'";
  return "'" + c + "'";
}

static String str(Object o) {
  return String.valueOf(o);
}
// replacement for class JavaTok
// maybe incomplete, might want to add floating point numbers
// todo also: extended multi-line strings

static int javaTok_n, javaTok_elements;
static boolean javaTok_opt;

static List<String> javaTok(String s) {
  return javaTok(s, null);
}

static List<String> javaTok(String s, List<String> existing) {
  ++javaTok_n;
  int nExisting = javaTok_opt && existing != null ? existing.size() : 0;
  List<String> tok = existing != null ? new ArrayList(nExisting) : new ArrayList();
  int l = s.length();
  
  int i = 0, n = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    if (n < nExisting && javaTok_isCopyable(existing.get(n), s, i, j))
      tok.add(existing.get(n));
    else
      tok.add(quickSubstring(s, i, j));
    ++n;
    i = j;
    if (i >= l) break;
    c = s.charAt(i); // cc is not needed in rest of loop body
    cc = s.substring(i, Math.min(i+2, l));

    // scan for non-whitespace
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        if (s.charAt(j) == opener || s.charAt(j) == '\n') { // end at \n to not propagate unclosed string literal errors
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
    } else if (Character.isJavaIdentifierStart(c))
      do ++j; while (j < l && (Character.isJavaIdentifierPart(s.charAt(j)) || "'".indexOf(s.charAt(j)) >= 0)); // for stuff like "don't"
    else if (Character.isDigit(c)) {
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
      if (j < l && s.charAt(j) == 'L') ++j; // Long constants like 1L
    } else if (cc.equals("[[")) {
      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));
      j = Math.min(j+2, l);
    } else if (cc.equals("[=") && i+2 < l && s.charAt(i+2) == '[') {
      do ++j; while (j+2 < l && !s.substring(j, j+3).equals("]=]"));
      j = Math.min(j+3, l);
    } else
      ++j;

    if (n < nExisting && javaTok_isCopyable(existing.get(n), s, i, j))
      tok.add(existing.get(n));
    else
      tok.add(quickSubstring(s, i, j));
    ++n;
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  javaTok_elements += tok.size();
  return tok;
}

static List<String> javaTok(List<String> tok) {
  return javaTok(join(tok), tok);
}

static boolean javaTok_isCopyable(String t, String s, int i, int j) {
  return t.length() == j-i
    && s.regionMatches(i, t, 0, j-i); // << could be left out, but that's brave
}
// hmm, this shouldn't call functions really. That was just
// for coroutines.
static boolean isTrue(Object o) {
  if (o instanceof Boolean)
    return ((Boolean) o).booleanValue();
  if (o == null) return false;
  return ((Boolean) callF(o)).booleanValue();
}

static boolean isTrue(Object pred, Object arg) {
  return booleanValue(callF(pred, arg));
}
static String boolArrayToHex(boolean[] a) {
  return bytesToHex(boolArrayToBytes(a));
}
static void swapElements(List l, int i, int j) {
  if (i == j) return;
  Object o = l.get(i);
  l.set(i, l.get(j));
  l.set(j, o);
}
static boolean isInteger(String s) {
  return s != null && Pattern.matches("\\-?\\d+", s);
}
static String substring(String s, int x) {
  return safeSubstring(s, x);
}

static String substring(String s, int x, int y) {
  return safeSubstring(s, x, y);
}
static int parseInt(String s) {
  return empty(s) ? 0 : Integer.parseInt(s);
}


// hopefully covers all cases :)
static String safeSubstring(String s, int x, int y) {
  if (s == null) return null;
  if (x < 0) x = 0;
  if (x > s.length()) return "";
  if (y < x) y = x;
  if (y > s.length()) y = s.length();
  return s.substring(x, y);
}

static String safeSubstring(String s, int x) {
  return safeSubstring(s, x, l(s));
}

static byte[] boolArrayToBytes(boolean[] a) {
  byte[] b = new byte[(l(a)+7)/8];
  for (int i = 0; i < l(a); i++)
    if (a[i])
      b[i/8] |= 1 << (i & 7);
  return b;
}
static String quickSubstring(String s, int i, int j) {
  if (i == j) return "";
  return s.substring(i, j);
}
static boolean booleanValue(Object o) {
  return eq(true, o);
}

}