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.*;
import net.luaos.tb.tb12.Sandbox;
import net.luaos.tb.remote.ServerConnection;
import org.luaj.vm2.*;
import org.luaj.vm2.lib.*;
import net.luaos.tb.tb12.Sandbox;
import net.luaos.tb.common.LuaTimeOutSandbox;
import net.luaos.tb.remote.ServerConnection;
public class main {


public static void main(String[] args) throws Exception {
  String text = getTextFromSucker("#1004698");
  String lua = callStrategy("#1004720", text);
  scoreTextPredictAlgo_buf = new StringBuilder();
  double score = scoreTextPredictAlgo(makeLuaTextPredictAlgo("L " + lua), text);
  print("Score: " + score);
  
  String s = str(scoreTextPredictAlgo_buf);
  print(unidiff(text, s));
  print("Length: " + l(text) + " vs " + l(s));
  
  if (l(text) == l(s)) {
    for (int i = 0; i < l(text); i++)
      if (text.charAt(i) != s.charAt(i))
        print(intToHex(text.charAt(i)) + " " + intToHex(s.charAt(i)));
  }
  
  print("Code MD5: " + md5(lua));
}

static String str(Object o) {
  return String.valueOf(o);
}
static interface Algorithm {
  String predict(int max);
  void feed(String s);
}

static class LuaAlgo implements Algorithm {
  LuaValue predict, feed;
  String feeding;
  
  LuaAlgo(String code) {
    Sandbox s = luaSandbox();
    evalLua(s, code);
    //print("KEYS: " + structure(s.keys()));
    predict = s.get("predict");
    if (predict.isnil()) predict = s.get("p");
    assertFalse(predict.isnil());
  }
  
  public String predict(int max) {
    LuaValue s = predict.call(Lua.value(max), feeding != null ? Lua.value(feeding) : Lua.NIL);
    feeding = null;
    return s.isnil() ? "" : s.tojstring();
  }
  
  public void feed(String s) {
    feeding = s;
  }
}

static Algorithm makeLuaTextPredictAlgo(String desc) {
  return new LuaAlgo(dropPrefix("L ", desc));
}
static String unidiff(String a, String b) {
  int contextSize = 1;
  return fromLines(BlockDiffer.generateUniDiff(toLines(a), toLines(b), contextSize));
}
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 StringBuilder scoreTextPredictAlgo_buf;

static double scoreTextPredictAlgo(Algorithm algorithm, String text) {
  long time = now();
  int score = 0;
  int n = l(text);

  for (int pos = 0; pos < n; ) {
    String s = algorithm.predict(n-pos);
    if (empty(s)) s = " "; // We're lenient
    
    if (l(s) > n-pos)
      s = substring(s, 0, n-pos);
    if (scoreTextPredictAlgo_buf != null) scoreTextPredictAlgo_buf.append(s);
    int j = pos+l(s);
    String real = substring(text, pos, j);
    score += getNumberOfEqualCharacters(real, s);
    algorithm.feed(real);
    pos = j;
  }
  
  double score2 = score*100.0/n;
  done_always(time, "SCORE: " + score + "/" + n + " = " + formatDouble(score2, 2) + "%");
  
  if (lastSilentException() != null)
    printStackTrace(lastSilentException());

  return score2;
}
static String getTextFromSucker(String suckerID) {
  Object sucker = run(suckerID);
  String text = (String) callOpt(sucker, "getText");
  return text;
}
static int l(Object[] 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 String callStrategy(LuaValue strategy, String text) {
  LuaValue result = strategy.call(text);
  assertTrue(result.isstring());
  return result.tojstring();
}

static String callStrategy(String strategyID, String text) {
  return callStrategy(loadStrategy(strategyID), text);
}

static String intToHex(int i) {
  return bytesToHex(intToBytes(i));
}
static String md5(String text) { try {
 
  if (text == null) return "-";
  return bytesToHex(md5_impl(text.getBytes("UTF-8"))); // maybe different than the way PHP does it...

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

static String md5(byte[] data) {
  if (data == null) return "-";
  return bytesToHex(md5_impl(data));
}

static byte[] md5_impl(byte[] data) {
 try {
  return MessageDigest.getInstance("MD5").digest(data);
 } catch (Exception e) { throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e); }
}

static String md5(File file) { try {
 
  return md5(loadBinaryFile(file));

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


static LuaValue evalLua(String code) {
  return quickLua(code).result;
}

static LuaValue evalLua(Sandbox sandbox, String code) {
  return quickLua(sandbox, code).result;
}
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 void assertFalse(Object o) {
  assertEquals(false, o);
}
  
static boolean assertFalse(boolean b) {
  if (b)
    throw fail("oops");
  return b;
}
static Class run(String progID, String... args) {
  Class main = hotwire(progID);
  callMain(main, args);
  return main;
}
static String fromLines(List<String> lines) {
  StringBuilder buf = new StringBuilder();
  if (lines != null)
    for (String line : lines)
      buf.append(line).append('\n');
  return buf.toString();
}

static String fromLines(String... lines) {
  return fromLines(asList(lines));
}
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 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 volatile int silentException_count;
static volatile Throwable silentException_lastException;

static void silentException(Throwable e) {
  ++silentException_count; // yeah it's not atomic :)
  silentException_lastException = e;
}

static Throwable lastSilentException() {
  return silentException_lastException;
}
  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 Sandbox luaSandbox(Object... outer) {
  Sandbox s = new Sandbox(ServerConnection.aServerConnection());
  for (int i = 0; i+1 < l(outer); i += 2)
    s.setOuter((String) outer[i], (LuaValue) outer[i+1]);
  return s;
}

static void assertTrue(Object o) {
  assertEquals(true, o);
}
  
static boolean assertTrue(String msg, boolean b) {
  if (!b)
    throw fail(msg);
  return b;
}

static boolean assertTrue(boolean b) {
  if (!b)
    throw fail("oops");
  return b;
}
static long now_virtualTime;
static long now() {
  return now_virtualTime != 0 ? now_virtualTime : System.currentTimeMillis();
}

static List<String> toLines(File f) {
  return toLines(loadTextFile(f));
}

  public static List<String> toLines(String s) {
    List<String> lines = new ArrayList<String>();
    if (s == null) return lines;
    int start = 0;
    while (true) {
      int i = toLines_nextLineBreak(s, start);
      if (i < 0) {
        if (s.length() > start) lines.add(s.substring(start));
        break;
      }

      lines.add(s.substring(start, i));
      if (s.charAt(i) == '\r' && i+1 < s.length() && s.charAt(i+1) == '\n')
        i += 2;
      else
        ++i;

      start = i;
    }
    return lines;
  }

  private static int toLines_nextLineBreak(String s, int start) {
    for (int i = start; i < s.length(); i++) {
      char c = s.charAt(i);
      if (c == '\r' || c == '\n')
        return i;
    }
    return -1;
  }
static String dropPrefix(String prefix, String s) {
  return s.startsWith(prefix) ? s.substring(l(prefix)) : s;
}
static byte[] intToBytes(int i) {
  return new byte[] {
          (byte) (i >>> 24),
          (byte) (i >>> 16),
          (byte) (i >>> 8),
          (byte) i};
}
  public static String formatDouble(double d, int digits) {
    String format = "0.";
    for (int i = 0; i < digits; i++) format += "#";
    return new java.text.DecimalFormat(format, new java.text.DecimalFormatSymbols(Locale.ENGLISH)).format(d);
  }

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 long done_always(long startTime, String desc) {
  long time = now()-startTime;
  print(desc + " [" + time + " ms]");
  return time;
}

static long done_always(String desc, long startTime) {
  return done_always(startTime, desc);
}

static long done_always(long startTime) {
  return done_always(startTime, "");
}
static int getNumberOfEqualCharacters(String a, String b) {
  int score = 0, n = min(l(a), l(b));
  for (int i = 0; i < n; i++)
    if (a.charAt(i) == b.charAt(i))
      ++score;
  return score;
}
static LuaValue loadStrategy(String id) {
  String lua = loadSnippet(id);
  Sandbox s = luaSandbox();
  evalLua(s, lua);
  LuaValue strategy = s.get("strategy");
  assertNotNil(strategy);
  return strategy;
}
public static byte[] loadBinaryFile(String fileName) {
 try {
  if (!new File(fileName).exists())
    return null;

  FileInputStream in = new FileInputStream(fileName);

  byte buf[] = new byte[1024];
  ByteArrayOutputStream out = new ByteArrayOutputStream();
  int l;
  while (true) {
    l = in.read(buf);
    if (l <= 0) break;
    out.write(buf, 0, l);
  }
  in.close();
  return out.toByteArray();
 } catch (IOException e) { throw new RuntimeException(e); }
}

public static byte[] loadBinaryFile(File file) {
  return loadBinaryFile(file.getPath());
}



static void callMain(Object c, String... args) {
  callOpt(c, "main", new Object[] {args});
}
static Object callF(Object f, Object... args) {
  return callFunction(f, args);
}
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;
}
// 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 int min(int a, int b) {
  return Math.min(a, b);
}

static double min(double a, double b) {
  return Math.min(a, b);
}

static double min(double[] c) {
  double x = Double.MAX_VALUE;
  for (double d : c) x = Math.min(x, d);
  return x;
}

static byte min(byte[] c) {
  byte x = 127;
  for (byte d : c) if (d < x) x = d;
  return x;
}
static String getStackTrace(Throwable throwable) {
  StringWriter writer = new StringWriter();
  throwable.printStackTrace(new PrintWriter(writer));
  return writer.toString();
}
  static boolean preferCached = false;
  static boolean loadSnippet_debug = false;

  public static String loadSnippet(String snippetID) {
    try {
      return loadSnippet(parseSnippetID(snippetID), preferCached);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static String loadSnippet(String snippetID, boolean preferCached) throws IOException {
    return loadSnippet(parseSnippetID(snippetID), preferCached);
  }

  public static String loadSnippet(long snippetID, boolean preferCached) throws IOException {
    String text;
    
    // boss bot disabled for now for shorter transpilations
    
    /*text = getSnippetFromBossBot(snippetID);
    if (text != null) return text;*/
    
    initSnippetCache();
    text = DiskSnippetCache_get(snippetID);
    
    if (preferCached && text != null)
      return text;
    
    try {
      if (loadSnippet_debug && text != null) System.err.println("md5: " + md5(text));
      URL url = new URL("http://tinybrain.de:8080/getraw.php?id=" + snippetID + "&utf8=1");
      text = loadPage(url);
    } catch (RuntimeException e) {
      e.printStackTrace();
      throw new IOException("Snippet #" + snippetID + " not found or not public");
    }

    try {
      initSnippetCache();
      DiskSnippetCache_put(snippetID, text);
    } catch (IOException e) {
      System.err.println("Minor warning: Couldn't save snippet to cache ("  + DiskSnippetCache_getDir() + ")");
    }

    return text;
  }

  static File DiskSnippetCache_dir;

  public static void initDiskSnippetCache(File dir) {
    DiskSnippetCache_dir = dir;
    dir.mkdirs();
  }

  public static synchronized String DiskSnippetCache_get(long snippetID) throws IOException {
    return loadTextFile(DiskSnippetCache_getFile(snippetID).getPath(), null);
  }

  private static File DiskSnippetCache_getFile(long snippetID) {
    return new File(DiskSnippetCache_dir, "" + snippetID);
  }

  public static synchronized void DiskSnippetCache_put(long snippetID, String snippet) throws IOException {
    saveTextFile(DiskSnippetCache_getFile(snippetID).getPath(), snippet);
  }

  public static File DiskSnippetCache_getDir() {
    return DiskSnippetCache_dir;
  }

  public static void initSnippetCache() {
    if (DiskSnippetCache_dir == null)
      initDiskSnippetCache(new File(System.getProperty("user.home"), ".tinybrain/snippet-cache"));
  }
  
  // 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);
    }
  }
// 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);
}
  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();
  }
 // aibo8.jar with Lua UTF8 fix


static LuaTimeOutSandbox.ResultWithStats quickLua(String code) {
  return quickLua(luaSandbox(), code);
}

static LuaTimeOutSandbox.ResultWithStats quickLua(Sandbox sandbox, String code) {
  return sandbox.callLuaWithStats(code, "unknown source");
}
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 <A> A assertEquals(Object x, A y) {
  return assertEquals(null, x, y);
}

static <A> A assertEquals(String msg, Object x, A y) {
  if (!(x == null ? y == null : x.equals(y)))
    throw fail((msg != null ? msg + ": " : "") + structure(x) + " != " + structure(y));
  return y;
}
static void assertNotNil(LuaValue l) {
  assertTrue(l != null && !l.isnil());
}
  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 String getType(Object o) {
  return getClassName(o);
}


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()));
  }
}
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 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);
  }

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

    if (contents != null)
      if (!tempFile.renameTo(file))
        throw new IOException("Can't rename " + tempFile + " to " + file);
  }
  
  public static void saveTextFile(File fileName, String contents) {
    try {
      saveTextFile(fileName.getPath(), contents);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

static String getClassName(Object o) {
  return o == null ? "null" : o.getClass().getName();
}
static boolean _inCore() {
  return false;
}

  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 boolean isSnippetID(String s) {
    try {
      parseSnippetID(s);
      return true;
    } catch (RuntimeException e) {
      return false;
    }
  }
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;
}
// 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;
}

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

static Object get(Object o, String field) {
  if (o instanceof Class) return get((Class) o, field);
  
  if (o instanceof Map)
    return ((Map) o).get(field);
    
  if (o.getClass().getName().equals("main$DynamicObject"))
    return call(get_raw(o, "fieldValues"), "get", field);
    
  return get_raw(o, field);
}

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 Class __javax;

static Class getJavaX() {
  return __javax;
}
  static ThreadLocal<String> loadPage_charset = new ThreadLocal<String>();
  static boolean loadPage_allowGzip = true, loadPage_debug;
  static boolean loadPage_anonymous; // don't send computer ID
  static int loadPage_verboseness = 100000;
  static int loadPage_retries = 60; // seconds

  public static String loadPageSilently(String url) {
    try {
      return loadPageSilently(new URL(loadPage_preprocess(url)));
    } catch (IOException e) { throw new RuntimeException(e); }
  }

  public static String loadPageSilently(URL url) {
    try {
      IOException e = null;
      for (int tries = 0; tries < loadPage_retries; tries++)
        try {
          URLConnection con = openConnection(url);
          return loadPage(con, url);
        } catch (IOException _e) {
          e = _e;
          print("Trying proxy because of: " + e);
          try {
            return loadPageThroughProxy(str(url));
          } catch (Throwable e2) {
            print("  " + exceptionToStringShort(e2));
          }
          sleepSeconds(1);
        }
      throw e;
    } catch (IOException e) { throw new RuntimeException(e); }
  }

  static String loadPage_preprocess(String url) {  
    if (url.startsWith("tb/"))
      url = "tinybrain.de:8080/" + url;
    if (url.indexOf("://") < 0)
      url = "http://" + url;
    return url;
  }
  
  public static String loadPage(String url) {
    try {
      url = loadPage_preprocess(url);
      print("Loading: " + url);
      return loadPageSilently(new URL(url));
    } catch (IOException e) { throw new RuntimeException(e); }
  }
  
  public static String loadPage(URL url) {
    print("Loading: " + url.toExternalForm());
    return loadPageSilently(url);
  }

  public static String loadPage(URLConnection con, URL url) throws IOException {
    try {
      if (!loadPage_anonymous) {
        String computerID = getComputerID();
        if (computerID != null)
          con.setRequestProperty("X-ComputerID", computerID);
      }
      if (loadPage_allowGzip)
        con.setRequestProperty("Accept-Encoding", "gzip");
    } catch (Throwable e) {} // fails if within doPost
    String contentType = con.getContentType();
    if (contentType == null)
      throw new IOException("Page could not be read: " + url);
    //print("Content-Type: " + contentType);
    String charset = loadPage_charset == null ? null : loadPage_charset.get();
    if (charset == null) charset = loadPage_guessCharset(contentType);
    
    InputStream in = con.getInputStream();
    if ("gzip".equals(con.getContentEncoding())) {
      if (loadPage_debug)
        print("loadPage: Using gzip.");
      in = new GZIPInputStream(in);
    }
    Reader r = new InputStreamReader(in, charset);
    
    StringBuilder buf = new StringBuilder();
    int n = 0;
    while (true) {
      int ch = r.read();
      if (ch < 0)
        break;
      buf.append((char) ch);
      ++n;
      if ((n % loadPage_verboseness) == 0) print("  " + n + " chars read");
    }
    return buf.toString();
  }
  
  static String loadPage_guessCharset(String contentType) {
    Pattern p = Pattern.compile("text/[a-z]+;\\s+charset=([^\\s]+)\\s*");
    Matcher m = p.matcher(contentType);
    /* If Content-Type doesn't match this pre-conception, choose default and hope for the best. */
    return m.matches() ? m.group(1) : "ISO-8859-1";
  }

static String structure(Object o) {
  HashSet refd = new HashSet();
  return structure_2(structure_1(o, 0, new IdentityHashMap(), refd), refd);
}

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

static String structure_1(Object o, int stringSizeLimit, IdentityHashMap<Object, Integer> seen, HashSet<Integer> refd) {
  if (o == null) return "null";
  
  // these are never back-referenced (for readability)
  
  if (o instanceof String)
    return quote(stringSizeLimit != 0 ? shorten((String) o, stringSizeLimit) : (String) o);
    
  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 = seen.get(o);
  if (ref != null) {
    refd.add(ref);
    return "r" + ref;
  }
      
  ref = seen.size()+1;
  seen.put(o, ref);
  String r = "m" + ref + " "; // marker

  String name = o.getClass().getName();

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

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

    int n = Array.getLength(o);
    for (int i = 0; i < n; i++) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(Array.get(o, i), stringSizeLimit, seen, refd));
    }
    return r + "array{" + 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"), stringSizeLimit, seen, refd));
    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, stringSizeLimit, seen, refd));
      }
    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, stringSizeLimit, seen, refd));
      }
      ++numFields;
   }
  } else {
    // regular class
    
    Class c = o.getClass();
    while (c != Object.class) {
      Field[] fields = c.getDeclaredFields();
      for (Field field : fields) {
        if ((field.getModifiers() & Modifier.STATIC) != 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, stringSizeLimit, seen, refd));
        }
        ++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 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 boolean isInteger(String s) {
  return s != null && Pattern.matches("\\-?\\d+", s);
}
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 Class mc() {
  return getMainClass();
}
static String quoteCharacter(char c) {
  if (c == '\'') return "'\\''";
  if (c == '\\') return "'\\\\'";
  return "'" + c + "'";
}

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 URLConnection openConnection(URL url) { try {
 
  ping();
  return url.openConnection();

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
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;
}
public static void copyFile(File src, File dest) { try {
 
  mkdirsForFile(dest);
  FileInputStream inputStream = new FileInputStream(src.getPath());
  FileOutputStream outputStream = new FileOutputStream(dest.getPath());
  try {
    copyStream(inputStream, outputStream);
    inputStream.close();
  } finally {
    outputStream.close();
  }

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static void sleepSeconds(double s) {
  if (s > 0) sleep(round(s*1000));
}
// 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
}
static String getComputerID() { try {
 
  return computerID();

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

static Object getMainBot() {
  return mainBot;
}
static List emptyList() {
  return new ArrayList();
  //ret Collections.emptyList();
}
static <A> ArrayList<A> litlist(A... a) {
  return new ArrayList<A>(Arrays.asList(a));
}
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 exceptionToStringShort(Throwable e) {
  e = getInnerException(e);
  String msg = unnull(e.getMessage());
  if (msg.indexOf("Error") < 0 && msg.indexOf("Exception") < 0)
    return baseClassName(e) + ": " + msg;
  else
    return msg;
}
static int parseInt(String s) {
  return empty(s) ? 0 : Integer.parseInt(s);
}
// 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 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 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;
}
static String loadPageThroughProxy(String url) {
  adbForward();
  DialogIO io = talkToOpt("localhost", 4995); // Test ADB Bridge
  if (io == null)
    io = talkToOpt(gateway(), 4999); // Phone, Public Comm Bot
  if (io == null) return null;
  String answer = unquote(io.ask(forward("Awareness", format("loadPage *", url))));
  io.close();
  if (swic(answer, "ok "))
    return answer.substring(3);
  throw fail(answer);
}


static Object getBot(String botID) {
  return callOpt(getMainBot(), "getBot", botID);
}

  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 DialogIO talkToOpt(String host, int port) {
  try {
    return talkTo(host, port);
  } catch (Throwable e) {
    return null;
  }
}
static String quickSubstring(String s, int i, int j) {
  if (i == j) return "";
  return s.substring(i, j);
}
static volatile boolean ping_pauseAll;
static int ping_sleep = 100; // poll pauseAll flag every 100
static volatile boolean ping_anyActions;
static Map<Thread, Object> ping_actions = synchroMap(new WeakHashMap());

// returns true if it did anything
static boolean ping() {
  if (ping_pauseAll) {
    do
      sleep(ping_sleep);
    while (ping_pauseAll); return true;
  }
  
  if (ping_anyActions) {
    Object action;
    synchronized(main.class) {
      action = ping_actions.get(currentThread());
      if (action instanceof Runnable)
        ping_actions.remove(currentThread());
      if (ping_actions.isEmpty()) ping_anyActions = false;
    }
    
    if (action instanceof Runnable)
      ((Runnable) action).run();
    else if (eq(action, "cancelled"))
      throw fail("Thread cancelled.");
  } return false;
}
static boolean swic(String a, String b) {
  return startsWithIgnoreCase(a, b);
}
static void sleep(long ms) {
  try {
    Thread.sleep(ms);
  } catch (Exception e) { throw new RuntimeException(e); }
}

static void sleep() { try {
 
  print("Sleeping.");
  synchronized(main.class) { main.class.wait(); }

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static String baseClassName(String className) {
  return substring(className, className.lastIndexOf('.'));
}

static String baseClassName(Object o) {
  return baseClassName(getClassName(o));
}
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 String forward(String bot, String msg, Object... args) {
  return format("please forward to bot *: *", bot, format(msg, args));
}
static Throwable getInnerException(Throwable e) {
  while (e.getCause() != null)
    e = e.getCause();
  return e;
}
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 String _computerID;
public static String computerID() { try {
 
  if (_computerID == null) {
    File file = new File(userHome(), ".tinybrain/computer-id");
    _computerID = loadTextFile(file.getPath(), null);
    if (_computerID == null) {
      _computerID = makeRandomID(12);
      saveTextFile(file.getPath(), _computerID);
    }
  }
  return _computerID;

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  static String format(String pat, Object... args) {
    return format3(pat, args);
  }

static TimedCache<String> adbForward_list = new TimedCache(10);

static void adbForward() {
  if (!isOnPATH("adb"))
    print("adb not on path");
  else {
    backtick_verbose = true;
    String list = adbForward_list.get(new Object() { Object get() { return backtick("adb forward --list"); }});
    if (!contains(list, "4995"))
      backtick("adb forward tcp:4995 tcp:4999");
  }
}
static boolean booleanValue(Object o) {
  return eq(true, o);
}
public static File mkdirsForFile(File file) {
  File dir = file.getParentFile();
  if (dir != null) // is null if file is in current dir
    dir.mkdirs();
  return file;
}

  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 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 long round(double d) {
  return Math.round(d);
}
static void copyStream(InputStream in, OutputStream out) { try {
 
  byte[] buf = new byte[65536];
  while (true) {
    int n = in.read(buf);
    if (n <= 0) return;
    out.write(buf, 0, n);
  }

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static String gateway() {
  return first(detectGateways());
}


static Thread currentThread() {
  return Thread.currentThread();
}
static boolean contains(Collection c, Object o) {
  return c != null && c.contains(o);
}

static boolean contains(Object[] x, Object o) {
  if (x != null)
    for (Object a : x)
      if (eq(a, o))
        return true;
  return false;
}

static boolean contains(String s, char c) {
  return s != null && s.indexOf(c) >= 0;
}

static boolean contains(String s, String b) {
  return s != null && s.indexOf(b) >= 0;
}
static DialogIO talkTo(int port) {
  return talkTo("localhost", port);
}

static int talkTo_defaultTimeout = 10000;

static DialogIO talkTo(String ip, int port) { try {
 
  final Socket s = new Socket();
  s.connect(new InetSocketAddress(ip, port), talkTo_defaultTimeout);
  //print("Talking to " + ip + ":" + port);

  final Writer w = new OutputStreamWriter(s.getOutputStream(), "UTF-8");
  final BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream(), "UTF-8"));
  return new DialogIO() {
    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;
    }
  };

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
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 int backtick_exitValue;
static boolean backtick_verbose;

public static String backtick(String cmd) { try {
 
  File outFile = File.createTempFile("_backtick", "");
  File scriptFile = File.createTempFile("_backtick", isWindows() ? ".bat" : "");

  String command = cmd + " >" + bashQuote(outFile.getPath()) + " 2>&1";
  //Log.info("[Backtick] " + command);
  try {
    if (backtick_verbose)
      print("backtick: command " + command);
    saveTextFile(scriptFile.getPath(), command);
    String[] command2;
    if (isWindows())
      command2 = new String[] { scriptFile.getPath() };
    else
      command2 = new String[] { "/bin/bash", scriptFile.getPath() };
    if (backtick_verbose)
      print("backtick: command2 " + structure(command2));
    Process process = Runtime.getRuntime().exec(command2);
    try {
      process.waitFor();
    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
    backtick_exitValue = process.exitValue();
    if (backtick_verbose)
      System.out.println("Process return code: " + backtick_exitValue);
    String result = loadTextFile(outFile.getPath(), "");
    if (backtick_verbose)
      print("[[\n" + result + "]]");
    return result;
  } finally {
    scriptFile.delete();
  }

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


static boolean startsWithIgnoreCase(String a, String b) {
  return a != null && a.regionMatches(true, 0, b, 0, b.length());
}
static Object first(Object list) {
  return ((List) list).isEmpty() ? null : ((List) list).get(0);
}

static <A> A first(List<A> list) {
  return list.isEmpty() ? null : list.get(0);
}

static <A> A first(A[] bla) {
  return bla == null || bla.length == 0 ? null : bla[0];
}

static <A> A first(Iterable<A> i) {
  if (i == null) return null;
  Iterator<A> it = i.iterator();
  return it.hasNext() ? it.next() : null;
}

  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 boolean isOnPATH(String cmd) {
  String path = System.getenv("PATH");
  List<String> dirs = splitAt(path, File.pathSeparator);
  String c = isWindows() ? cmd + ".exe" : cmd;
  for (String dir : dirs)
    if (new File(dir, c).isFile())
      return true;
  return false;
}
static TimedCache<List<String>> detectGateways_cache = new TimedCache(5);

static synchronized List<String> detectGateways() { try {
 
  if (detectGateways_cache.has()) return detectGateways_cache.getNoClean();

  boolean win = isWindows();
  String s = backtick(win ? "ipconfig" : "ip route show");
  TreeSet<String> ips = new TreeSet<String>();
  for (String line : toLines(s))
    if (indexOfIgnoreCase(line, win ? "Gateway" : "via") >= 0)
      ips.addAll(regexpAll("\\d+\\.\\d+\\.\\d+\\.\\d+", line));
  return detectGateways_cache.set(new ArrayList<String>(ips));

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static Map synchroMap() {
  return synchroHashMap();
}

static <A, B> Map<A, B> synchroMap(Map<A, B> map) {
  return Collections.synchronizedMap(map);
}
static String dropSuffix(String suffix, String s) {
  return s.endsWith(suffix) ? s.substring(0, l(s)-l(suffix)) : s;
}
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);
}


public static boolean isWindows() {
  return System.getProperty("os.name").contains("Windows");
}
/** possibly improvable */
static String bashQuote(String text) {
  if (text == null) return null;
  return "\"" + text
    .replace("\\", "\\\\")
    .replace("\"", "\\\"")
    .replace("\n", "\\n")
    .replace("\r", "\\r") + "\"";
}

static String bashQuote(File f) {
  return bashQuote(f.getAbsolutePath());
}
static List<String> splitAt(String s, String splitter) {
  List<String> parts = new ArrayList<String>();
  int i = 0;
  if (s != null)
    while (i < l(s)) {
      int j = indexOf(s, splitter, i);
      if (j < 0) j = l(s);
      parts.add(substring(s, i, j));
      i = j+l(splitter);
    }
  return parts;
}
// works on lists and strings and null

static int indexOfIgnoreCase(Object a, Object b) {
  if (a == null) return -1;
  if (a instanceof String) {
     Matcher m = Pattern.compile((String) b, Pattern.CASE_INSENSITIVE + Pattern.LITERAL).matcher((String) a);
     if (m.find()) return m.start(); else return -1;
  }
  if (a instanceof List) {
    for (int i = 0; i < ((List) a).size(); i++) {
      Object o = ((List) a).get(i);
      if (o != null && ((String) o).equalsIgnoreCase((String) b))
        return i;
    }
    return -1;
  }
  throw fail("Unknown type: " + a);
}
static boolean isIdentifier(String s) {
  return isJavaIdentifier(s);
}
static boolean isNonNegativeInteger(String s) {
  return s != null && Pattern.matches("\\d+", s);
}
// 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 List<String> regexpAll(String pattern, String text) {
  List<String> matches = new ArrayList<String>();
  Matcher matcher = Pattern.compile(pattern).matcher(text);
  while (matcher.find())
    matches.add(matcher.group());
  return matches;
}
static Map synchroHashMap() {
  return Collections.synchronizedMap(new HashMap());
}

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 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 <A> int indexOf(List<A> l, A a, int startIndex) {
  if (l == null) return -1;
  for (int i = startIndex; i < l(l); i++)
    if (eq(l.get(i), a))
      return i;
  return -1;
}

static <A> int indexOf(List<A> l, A a) {
  if (l == null) return -1;
  return l.indexOf(a);
}

static int indexOf(String a, String b) {
  return a == null || b == null ? -1 : a.indexOf(b);
}

static int indexOf(String a, String b, int i) {
  return a == null || b == null ? -1 : a.indexOf(b, i);
}

static int indexOf(String a, int i, String b) {
  return a == null || b == null ? -1 : a.indexOf(b, i);
}

static <A> int indexOf(A[] x, A a) {
  if (x == null) return -1;
  for (int i = 0; i < l(x); i++)
    if (eq(x[i], a))
      return i;
  return -1;
}


static class TimedCache<A> {
  long timeout;
  A value;
  long set;
  
  // stats
  int stores, fails, hits;

  // 0 = no timeout  
  TimedCache(double timeoutSeconds) {
    timeout = toMS(timeoutSeconds);
  }
  
  synchronized A set(A a) {
    ++stores;
    value = a;
    set = now();
    return a;
  }
  
  synchronized boolean has() {
    clean();
    if (set != 0) {
      ++hits; return true;
    }
    ++fails; return false;
  }
  
  synchronized A get() {
    clean();
    if (set != 0) ++hits; else ++fails;
    return value;
  }
  
  synchronized A get(Object makerFunction) {
    if (has()) return getNoClean();
    A a = (A) ( callF(makerFunction));
    return set(a);
  }
  
  synchronized A getNoClean() {
    return value;
  }
  
  // clear if timed out
  synchronized void clean() {
    if (timeout > 0 && now() > set+timeout) clear();
  }
  
  // clear now
  synchronized void clear() {
    set = 0;
    value = null;
  }
  
  synchronized String stats() {
    return "Stores: " + stores + ", hits: " + hits + ", fails: " + fails;
  }
}


static class BlockDiff {
  public CopyBlock asCopyBlock() { return null; }
  public NewBlock  asNewBlock () { return null; }
}

static class CopyBlock extends BlockDiff {
  int firstLine, lines;

  CopyBlock(int firstLine, int lines) {
    this.firstLine = firstLine;
    this.lines = lines;
  }

  public CopyBlock asCopyBlock() { return this; }
  public int getFirstLine() { return firstLine; }
  public int getLines() { return lines; }
}

static class NewBlock extends BlockDiff {
  int originalStart;
  List<String> contents;

  NewBlock(int originalStart, List<String> contents) {
    this.originalStart = originalStart;
    this.contents = contents;
  }

  public NewBlock  asNewBlock () { return this; }

  public int getOriginalStart() {
    return originalStart;
  }

  public List<String> getContents() {
    return contents;
  }
}

static class ExplodedLine {
  int type;
  String left, right;
  int leftIndex, rightIndex;

  ExplodedLine(int type, String left, String right, int leftIndex, int rightIndex) {
    this.type = type;
    this.left = left;
    this.right = right;
    this.leftIndex = leftIndex;
    this.rightIndex = rightIndex;
  }
  
  public int getType() {
    return type;
  }

  public String getLeft() {
    return left;
  }

  public String getRight() {
    return right;
  }

  public int getLeftIndex() {
    return leftIndex;
  }

  public int getRightIndex() {
    return rightIndex;
  }
}

static class BlockDiffer {
  public static final int IDENTICAL = 0;
  public static final int DIFFERENT = 1;
  public static final int LEFT_ONLY = 2;
  public static final int RIGHT_ONLY = 3;

  private static void printChange(EGDiff.change change) {
    if (change != null) {
      System.out.println("line0="+change.line0+", line1="+change.line1
        +", inserted="+change.inserted+", deleted="+change.deleted);
      printChange(change.link);
    }
  }


  /** Generates the text content of a Unified-format context diff between 2 files
   *  (NB the 'files-changed' header must be added separately).
   */
  public static List<String> generateUniDiff(List<String> fileA, List<String> fileB, int contextSize) {
    EGDiff diff = new EGDiff(fileA.toArray(), fileB.toArray());
    EGDiff.change change = diff.diff_2(false);

    if (change != null) {
      int inserted, deleted;
      List<String> hunkLines = new ArrayList<String>();
      int cumulExtraLinesBwrtA = 0;

      // Each hunk is generated with a header
      do {
        int line0 = change.line0, line1 = change.line1;
        int changeStart = ((line1 < line0) ? line1 : line0);
        int contextStart = ((changeStart > contextSize) ? changeStart - contextSize : 0);
        int headerPosn = hunkLines.size();

        // Provide the first lines of context
        for (int i = contextStart; i < changeStart; i++)
          //System.out.println(" " + fileA.get(i));
          hunkLines.add(" " + fileA.get(i));

        boolean hunkFinish = false;
        // Step through each change giving the change lines and following context
        do {
          inserted = change.inserted;
          deleted = change.deleted;
          line0 = change.line0;
          line1 = change.line1;

          if (line1 < line0) // An insert comes earlier
            while (inserted-- > 0)
              hunkLines.add("+" + fileB.get(line1++));
          while (deleted-- > 0)
            hunkLines.add("-" + fileA.get(line0++));
          while (inserted-- > 0)
            hunkLines.add("+" + fileB.get(line1++));

          // Lines following are trailing context, identical in fileA and fileB
          // The next change may overlap the context, so check and if so, form one hunk
          EGDiff.change nextChange = change.link;
          int nextChangeStart = fileA.size();
          if (nextChange != null)
            nextChangeStart = ((nextChange.line1 < nextChange.line0) ? nextChange.line1 : nextChange.line0);

          if (nextChangeStart - line0 > contextSize * 2) { // A separate hunk
            nextChangeStart = line0 + contextSize;
            hunkFinish = true;
          }
          if (nextChangeStart > fileA.size())
            nextChangeStart = fileA.size(); // Limit to file size
          while (line0 < nextChangeStart) {
            hunkLines.add(" " + fileA.get(line0++));
            line1++; // Keep in sync with trailing context
          }

          change = change.link;
        } while (!hunkFinish && change != null);

        int hunkStartB = contextStart + cumulExtraLinesBwrtA;
        int hunkTotA = line0 - contextStart;
        int hunkTotB = line1 - hunkStartB;

        hunkLines.add(headerPosn, "@@ -" + (contextStart + 1) + ',' + hunkTotA +
                        " +" + (hunkStartB + 1) + ',' + hunkTotB + " @@");
        cumulExtraLinesBwrtA += hunkTotB - hunkTotA;

      } while (change != null);

      return hunkLines;
    }
    return null;
  }

/* For testing:
  private static void printUniDiff(List<String> fileA, List<String> fileB, int contextSize) {
    List<String> uniDiff = generateUniDiff(fileA, fileB, contextSize);

    if (uniDiff != null)
      for (int j = 0; j < uniDiff.size(); j++)
        System.out.println(uniDiff.get(j));
  }
 */


  public static List<BlockDiff> diffLines(List<String> lines, List<String> reference) {
    List<BlockDiff> diffs = new ArrayList<BlockDiff>();

    EGDiff diff = new EGDiff(reference.toArray(), lines.toArray());
    EGDiff.change change = diff.diff_2(false);
    //printChange(change);
    //printUniDiff(reference, lines, 3);

    int l0 = 0, l1 = 0;
    while (change != null) {
      if (change.line0 > l0 && change.line1 > l1)
        diffs.add(new CopyBlock(l0, change.line0-l0));

      if (change.inserted != 0)
        diffs.add(new NewBlock(change.line1, lines.subList(change.line1, change.line1+change.inserted)));

      l0 = change.line0 + change.deleted;
      l1 = change.line1 + change.inserted;
      change = change.link;
    }

    if (l0 < reference.size())
      diffs.add(new CopyBlock(l0, reference.size()-l0));

    return diffs;
  }

  /** fills files with empty lines to align matching blocks
   *
   * @param file1 first file
   * @param file2 second file
   * @return an array with two lists
   */
  public static List<ExplodedLine> explode(List<String> file1, List<String> file2) {
    List<ExplodedLine> lines = new ArrayList<ExplodedLine>();
    List<BlockDiff> diffs = BlockDiffer.diffLines(file2, file1);
    int lastLineCopied = 0, rightOnlyStart = -1, rightPosition = 0;
    for (int i = 0; i < diffs.size(); i++) {
      BlockDiff diff = diffs.get(i);
      if (diff instanceof CopyBlock) {
        CopyBlock copyBlock = (CopyBlock) diff;
        if (lastLineCopied < copyBlock.getFirstLine()) {
          if (rightOnlyStart >= 0) {
            int overlap = Math.min(lines.size()-rightOnlyStart, copyBlock.getFirstLine()-lastLineCopied);
            //lines.subList(rightOnlyStart, rightOnlyStart+overlap).clear();
            convertRightOnlyToDifferent(lines, rightOnlyStart, overlap, file1, lastLineCopied);
            lastLineCopied += overlap;
          }
          addBlock(lines, LEFT_ONLY, file1, lastLineCopied, copyBlock.getFirstLine(), lastLineCopied, -1);
        }
        addBlock(lines, IDENTICAL, file1, copyBlock.getFirstLine(), copyBlock.getFirstLine()+copyBlock.getLines(),
          copyBlock.getFirstLine(), rightPosition);
        rightPosition += copyBlock.getLines();
        lastLineCopied = copyBlock.getFirstLine()+copyBlock.getLines();
        rightOnlyStart = -1;
      } else if (diff instanceof NewBlock) {
        NewBlock newBlock = (NewBlock) diff;
        /*if (nextDiff instanceof BlockDiffer.CopyBlock) {
          BlockDiffer.CopyBlock copyBlock = (BlockDiffer.CopyBlock) nextDiff;
          copyBlock.getFirstLine()-lastLineCopied*/
        rightOnlyStart = lines.size();
        addBlock(lines, RIGHT_ONLY, newBlock.getContents(), 0, newBlock.getContents().size(), -1, rightPosition);
        rightPosition += newBlock.getContents().size();
      }
    }

    if (rightOnlyStart >= 0) {
      int overlap = Math.min(lines.size()-rightOnlyStart, file1.size()-lastLineCopied);
      //lines.subList(rightOnlyStart, rightOnlyStart+overlap).clear();
      convertRightOnlyToDifferent(lines, rightOnlyStart, overlap, file1, lastLineCopied);
      lastLineCopied += overlap;
    }
    addBlock(lines, LEFT_ONLY, file1, lastLineCopied, file1.size(), lastLineCopied, -1);

    return lines;
  }

  private static void convertRightOnlyToDifferent(List<ExplodedLine> lines, int start, int numLines,
                                                  List<String> leftLines, int leftStart) {
    for (int i = 0; i < numLines; i++) {
      ExplodedLine line = lines.get(start+i);
      lines.set(start+i,
        new ExplodedLine(DIFFERENT, leftLines.get(i+leftStart), line.getRight(), i+leftStart, line.getRightIndex()));
    }
  }

  private static void addBlock(List<ExplodedLine> lines, int type, List<String> srcLines, int start, int end,
                               int leftStart, int rightStart) {
    for (int i = start; i < end; i++)
      lines.add(new ExplodedLine(type, type == RIGHT_ONLY ? "" : srcLines.get(i),
                                       type == LEFT_ONLY ? "" : srcLines.get(i),
                                       type == RIGHT_ONLY ? -1 : i - start + leftStart,
                                       type == LEFT_ONLY ? -1 : i - start + rightStart));
  }

  public static List<ExplodedLine> condense(List<ExplodedLine> lines) {
    List<ExplodedLine> result = new ArrayList<ExplodedLine>();
    for (Iterator<ExplodedLine> i = lines.iterator(); i.hasNext();) {
      ExplodedLine line = i.next();
      if (line.getType() == IDENTICAL) {
        if (result.isEmpty() || result.get(result.size()-1).getType() != IDENTICAL)
          result.add(new ExplodedLine(IDENTICAL, "[...]", "[...]", -1, -1));
      } else
        result.add(line);
    }
    return result;
  }
}

  static abstract class DialogIO {
    String line;
    boolean eos;
    
    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 (!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 long toMS(double seconds) {
  return (long) (seconds*1000);
}
static void set(Object o, String field, Object value) {
  if (o instanceof Class) set((Class) o, field, value);
  else try {
    Field f = set_findField(o.getClass(), field);
    smartSet(f, o, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static void set(Class c, String field, Object value) {
  try {
    Field f = set_findStaticField(c, field);
    smartSet(f, null, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}
  
static Field set_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 set_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 BufferedReader readLine_reader;

static String readLine() {
  return (String) call(getJavaX(), "readLine");
}


/**
 * A class to compare vectors of objects.  The result of comparison
 * is a list of <code>change</code> objects which form an
 * edit script.  The objects compared are traditionally lines
 * of text from two files.  Comparison options such as "ignore
 * whitespace" are implemented by modifying the <code>equals</code>
 * and <code>hashcode</code> methods for the objects compared.
 * <p/>
 * The basic algorithm is described in: </br>
 * "An O(ND) Difference Algorithm and its Variations", Eugene Myers,
 * Algorithmica Vol. 1 No. 2, 1986, p 251.
 * <p/>
 * This class outputs different results from GNU diff 1.15 on some
 * inputs.  Our results are actually better (smaller change list, smaller
 * total size of changes), but it would be nice to know why.  Perhaps
 * there is a memory overwrite bug in GNU diff 1.15.
 *
 * @author Stuart D. Gathman, translated from GNU diff 1.15
 *         Copyright (C) 2000  Business Management Systems, Inc.
 *         <p/>
 *         This program is free software; you can redistribute it and/or modify
 *         it under the terms of the GNU General Public License as published by
 *         the Free Software Foundation; either version 1, or (at your option)
 *         any later version.
 *         <p/>
 *         This program is distributed in the hope that it will be useful,
 *         but WITHOUT ANY WARRANTY; without even the implied warranty of
 *         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *         GNU General Public License for more details.
 *         <p/>
 *         You should have received a copy of the <a href=COPYING.txt>
 *         GNU General Public License</a>
 *         along with this program; if not, write to the Free Software
 *         Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

static class EGDiff {

  /**
   * Prepare to find differences between two arrays.  Each element of
   * the arrays is translated to an "equivalence number" based on
   * the result of <code>equals</code>.  The original Object arrays
   * are no longer needed for computing the differences.  They will
   * be needed again later to print the results of the comparison as
   * an edit script, if desired.
   */
  public EGDiff(Object[] a, Object[] b) {
    Hashtable h = new Hashtable(a.length + b.length);
    filevec[0] = new file_data(a, h);
    filevec[1] = new file_data(b, h);
  }

  /**
   * 1 more than the maximum equivalence value used for this or its
   * sibling file.
   */
  private int equiv_max = 1;

  /**
   * When set to true, the comparison uses a heuristic to speed it up.
   * With this heuristic, for files with a constant small density
   * of changes, the algorithm is linear in the file size.
   */
  public boolean heuristic = false;

  /**
   * When set to true, the algorithm returns a guarranteed minimal
   * set of changes.  This makes things slower, sometimes much slower.
   */
  public boolean no_discards = false;

  private int[] xvec, yvec;	/* Vectors being compared. */
  private int[] fdiag;		/* Vector, indexed by diagonal, containing
				   the X coordinate of the point furthest
				   along the given diagonal in the forward
				   search of the edit matrix. */
  private int[] bdiag;		/* Vector, indexed by diagonal, containing
				   the X coordinate of the point furthest
				   along the given diagonal in the backward
				   search of the edit matrix. */
  private int fdiagoff, bdiagoff;
  private final file_data[] filevec = new file_data[2];
  private int cost;

  /**
   * Find the midpoint of the shortest edit script for a specified
   * portion of the two files.
   * <p/>
   * We scan from the beginnings of the files, and simultaneously from the ends,
   * doing a breadth-first search through the space of edit-sequence.
   * When the two searches meet, we have found the midpoint of the shortest
   * edit sequence.
   * <p/>
   * The value returned is the number of the diagonal on which the midpoint lies.
   * The diagonal number equals the number of inserted lines minus the number
   * of deleted lines (counting only lines before the midpoint).
   * The edit cost is stored into COST; this is the total number of
   * lines inserted or deleted (counting only lines before the midpoint).
   * <p/>
   * This function assumes that the first lines of the specified portions
   * of the two files do not match, and likewise that the last lines do not
   * match.  The caller must trim matching lines from the beginning and end
   * of the portions it is going to specify.
   * <p/>
   * Note that if we return the "wrong" diagonal value, or if
   * the value of bdiag at that diagonal is "wrong",
   * the worst this can do is cause suboptimal diff output.
   * It cannot cause incorrect diff output.
   */

  private int diag(int xoff, int xlim, int yoff, int ylim) {
    final int[] fd = fdiag;	// Give the compiler a chance.
    final int[] bd = bdiag;	// Additional help for the compiler.
    final int[] xv = xvec;		// Still more help for the compiler.
    final int[] yv = yvec;		// And more and more . . .
    final int dmin = xoff - ylim;	// Minimum valid diagonal.
    final int dmax = xlim - yoff;	// Maximum valid diagonal.
    final int fmid = xoff - yoff;	// Center diagonal of top-down search.
    final int bmid = xlim - ylim;	// Center diagonal of bottom-up search.
    int fmin = fmid, fmax = fmid;	// Limits of top-down search.
    int bmin = bmid, bmax = bmid;	// Limits of bottom-up search.
    /* True if southeast corner is on an odd
				     diagonal with respect to the northwest. */
    final boolean odd = (fmid - bmid & 1) != 0;

    fd[fdiagoff + fmid] = xoff;
    bd[bdiagoff + bmid] = xlim;

    for (int c = 1; ; ++c) {
      int d;			/* Active diagonal. */
      boolean big_snake = false;

      /* Extend the top-down search by an edit step in each diagonal. */
      if (fmin > dmin)
        fd[fdiagoff + --fmin - 1] = -1;
      else
        ++fmin;
      if (fmax < dmax)
        fd[fdiagoff + ++fmax + 1] = -1;
      else
        --fmax;
      for (d = fmax; d >= fmin; d -= 2) {
        int x, y, oldx, tlo = fd[fdiagoff + d - 1], thi = fd[fdiagoff + d + 1];

        if (tlo >= thi)
          x = tlo + 1;
        else
          x = thi;
        oldx = x;
        y = x - d;
        while (x < xlim && y < ylim && xv[x] == yv[y]) {
          ++x;
          ++y;
        }
        if (x - oldx > 20)
          big_snake = true;
        fd[fdiagoff + d] = x;
        if (odd && bmin <= d && d <= bmax && bd[bdiagoff + d] <= fd[fdiagoff + d]) {
          cost = 2 * c - 1;
          return d;
        }
      }

      /* Similar extend the bottom-up search. */
      if (bmin > dmin)
        bd[bdiagoff + --bmin - 1] = Integer.MAX_VALUE;
      else
        ++bmin;
      if (bmax < dmax)
        bd[bdiagoff + ++bmax + 1] = Integer.MAX_VALUE;
      else
        --bmax;
      for (d = bmax; d >= bmin; d -= 2) {
        int x, y, oldx, tlo = bd[bdiagoff + d - 1], thi = bd[bdiagoff + d + 1];

        if (tlo < thi)
          x = tlo;
        else
          x = thi - 1;
        oldx = x;
        y = x - d;
        while (x > xoff && y > yoff && xv[x - 1] == yv[y - 1]) {
          --x;
          --y;
        }
        if (oldx - x > 20)
          big_snake = true;
        bd[bdiagoff + d] = x;
        if (!odd && fmin <= d && d <= fmax && bd[bdiagoff + d] <= fd[fdiagoff + d]) {
          cost = 2 * c;
          return d;
        }
      }

      /* Heuristic: check occasionally for a diagonal that has made
         lots of progress compared with the edit distance.
         If we have any such, find the one that has made the most
         progress and return it as if it had succeeded.

         With this heuristic, for files with a constant small density
         of changes, the algorithm is linear in the file size.  */

      if (c > 200 && big_snake && heuristic) {
        int best = 0;
        int bestpos = -1;

        for (d = fmax; d >= fmin; d -= 2) {
          int dd = d - fmid;
          if ((fd[fdiagoff + d] - xoff) * 2 - dd > 12 * (c + (dd > 0 ? dd : -dd))) {
            if (fd[fdiagoff + d] * 2 - dd > best
              && fd[fdiagoff + d] - xoff > 20
              && fd[fdiagoff + d] - d - yoff > 20) {
              int k;
              int x = fd[fdiagoff + d];

              /* We have a good enough best diagonal;
                 now insist that it end with a significant snake.  */
              for (k = 1; k <= 20; k++)
                if (xvec[x - k] != yvec[x - d - k])
                  break;

              if (k == 21) {
                best = fd[fdiagoff + d] * 2 - dd;
                bestpos = d;
              }
            }
          }
        }
        if (best > 0) {
          cost = 2 * c - 1;
          return bestpos;
        }

        best = 0;
        for (d = bmax; d >= bmin; d -= 2) {
          int dd = d - bmid;
          if ((xlim - bd[bdiagoff + d]) * 2 + dd > 12 * (c + (dd > 0 ? dd : -dd))) {
            if ((xlim - bd[bdiagoff + d]) * 2 + dd > best
              && xlim - bd[bdiagoff + d] > 20
              && ylim - (bd[bdiagoff + d] - d) > 20) {
              /* We have a good enough best diagonal;
                 now insist that it end with a significant snake.  */
              int k;
              int x = bd[bdiagoff + d];

              for (k = 0; k < 20; k++)
                if (xvec[x + k] != yvec[x - d + k])
                  break;
              if (k == 20) {
                best = (xlim - bd[bdiagoff + d]) * 2 + dd;
                bestpos = d;
              }
            }
          }
        }
        if (best > 0) {
          cost = 2 * c - 1;
          return bestpos;
        }
      }
    }
  }

  /**
   * Compare in detail contiguous subsequences of the two files
   * which are known, as a whole, to match each other.
   * <p/>
   * The results are recorded in the vectors filevec[N].changed_flag, by
   * storing a 1 in the element for each line that is an insertion or deletion.
   * <p/>
   * The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.
   * <p/>
   * Note that XLIM, YLIM are exclusive bounds.
   * All line numbers are origin-0 and discarded lines are not counted.
   */

  private void compareseq(int xoff, int xlim, int yoff, int ylim) {
    /* Slide down the bottom initial diagonal. */
    while (xoff < xlim && yoff < ylim && xvec[xoff] == yvec[yoff]) {
      ++xoff;
      ++yoff;
    }
    /* Slide up the top initial diagonal. */
    while (xlim > xoff && ylim > yoff && xvec[xlim - 1] == yvec[ylim - 1]) {
      --xlim;
      --ylim;
    }
    
    /* Handle simple cases. */
    if (xoff == xlim)
      while (yoff < ylim)
        filevec[1].changed_flag[1 + filevec[1].realindexes[yoff++]] = true;
    else if (yoff == ylim)
      while (xoff < xlim)
        filevec[0].changed_flag[1 + filevec[0].realindexes[xoff++]] = true;
    else {
      /* Find a point of correspondence in the middle of the files.  */

      int d = diag(xoff, xlim, yoff, ylim);
      int c = cost;
      int b = bdiag[bdiagoff + d];

      if (c == 1) {
        /* This should be impossible, because it implies that
           one of the two subsequences is empty,
           and that case was handled above without calling `diag'.
           Let's verify that this is true.  */
        throw new IllegalArgumentException("Empty subsequence");
      } else {
        /* Use that point to split this problem into two subproblems.  */
        compareseq(xoff, b, yoff, b - d);
        /* This used to use f instead of b,
           but that is incorrect!
           It is not necessarily the case that diagonal d
           has a snake from b to f.  */
        compareseq(b, xlim, b - d, ylim);
      }
    }
  }

  /**
   * Discard lines from one file that have no matches in the other file.
   */

  private void discard_confusing_lines() {
    filevec[0].discard_confusing_lines(filevec[1]);
    filevec[1].discard_confusing_lines(filevec[0]);
  }

  private boolean inhibit = false;

  /**
   * Adjust inserts/deletes of blank lines to join changes
   * as much as possible.
   */

  private void shift_boundaries() {
    if (inhibit)
      return;
    filevec[0].shift_boundaries(filevec[1]);
    filevec[1].shift_boundaries(filevec[0]);
  }

  public interface ScriptBuilder {
    /**
     * Scan the tables of which lines are inserted and deleted,
     * producing an edit script.
     *
     * @param changed0 true for lines in first file which do not match 2nd
     * @param len0     number of lines in first file
     * @param changed1 true for lines in 2nd file which do not match 1st
     * @param len1     number of lines in 2nd file
     * @return a linked list of changes - or null
     */
    public change build_script(boolean[] changed0, int len0,
                               boolean[] changed1, int len1);
  }

  /**
   * Scan the tables of which lines are inserted and deleted,
   * producing an edit script in reverse order.
   */

  static class ReverseScript implements ScriptBuilder {
    public change build_script(final boolean[] changed0, int len0,
                               final boolean[] changed1, int len1) {
      change script = null;
      int i0 = 0, i1 = 0;
      while (i0 < len0 || i1 < len1) {
        if (changed0[1 + i0] || changed1[1 + i1]) {
          int line0 = i0, line1 = i1;

          /* Find # lines changed here in each file.  */
          while (changed0[1 + i0]) ++i0;
          while (changed1[1 + i1]) ++i1;

          /* Record this change.  */
          script = new change(line0, line1, i0 - line0, i1 - line1, script);
        }

        /* We have reached lines in the two files that match each other.  */
        i0++;
        i1++;
      }

      return script;
    }
  }

  static class ForwardScript implements ScriptBuilder {
    /**
     * Scan the tables of which lines are inserted and deleted,
     * producing an edit script in forward order.
     */
    public change build_script(final boolean[] changed0, int len0,
                               final boolean[] changed1, int len1) {
      change script = null;
      int i0 = len0, i1 = len1;

      while (i0 >= 0 || i1 >= 0) {
        if (changed0[i0] || changed1[i1]) {
          int line0 = i0, line1 = i1;

          /* Find # lines changed here in each file.  */
          while (changed0[i0]) --i0;
          while (changed1[i1]) --i1;

          /* Record this change.  */
          script = new change(i0, i1, line0 - i0, line1 - i1, script);
        }

        /* We have reached lines in the two files that match each other.  */
        i0--;
        i1--;
      }

      return script;
    }
  }

  /**
   * Standard ScriptBuilders.
   */
  public final static ScriptBuilder
    forwardScript = new ForwardScript(),
  reverseScript = new ReverseScript();

  /* Report the differences of two files.  DEPTH is the current directory
     depth. */
  public final change diff_2(final boolean reverse) {
    return diff(reverse ? reverseScript : forwardScript);
  }

  /**
   * Get the results of comparison as an edit script.  The script
   * is described by a list of changes.  The standard ScriptBuilder
   * implementations provide for forward and reverse edit scripts.
   * Alternate implementations could, for instance, list common elements
   * instead of differences.
   *
   * @param bld an object to build the script from change flags
   * @return the head of a list of changes
   */
  public change diff(final ScriptBuilder bld) {

    /* Some lines are obviously insertions or deletions
       because they don't match anything.  Detect them now,
       and avoid even thinking about them in the main comparison algorithm.  */

    discard_confusing_lines();

    /* Now do the main comparison algorithm, considering just the
       undiscarded lines.  */

    xvec = filevec[0].undiscarded;
    yvec = filevec[1].undiscarded;

    int diags =
      filevec[0].nondiscarded_lines + filevec[1].nondiscarded_lines + 3;
    fdiag = new int[diags];
    fdiagoff = filevec[1].nondiscarded_lines + 1;
    bdiag = new int[diags];
    bdiagoff = filevec[1].nondiscarded_lines + 1;

    compareseq(0, filevec[0].nondiscarded_lines,
      0, filevec[1].nondiscarded_lines);
    fdiag = null;
    bdiag = null;

    /* Modify the results slightly to make them prettier
       in cases where that can validly be done.  */

    shift_boundaries();

    /* Get the results of comparison in the form of a chain
       of `struct change's -- an edit script.  */
    return bld.build_script(filevec[0].changed_flag,
      filevec[0].buffered_lines,
      filevec[1].changed_flag,
      filevec[1].buffered_lines);

  }

  /**
   * The result of comparison is an "edit script": a chain of change objects.
   * Each change represents one place where some lines are deleted
   * and some are inserted.
   * <p/>
   * LINE0 and LINE1 are the first affected lines in the two files (origin 0).
   * DELETED is the number of lines deleted here from file 0.
   * INSERTED is the number of lines inserted here in file 1.
   * <p/>
   * If DELETED is 0 then LINE0 is the number of the line before
   * which the insertion was done; vice versa for INSERTED and LINE1.
   */

  public static class change {
    /**
     * Previous or next edit command.
     */
    public change link;
    /**
     * # lines of file 1 changed here.
     */
    public final int inserted;
    /**
     * # lines of file 0 changed here.
     */
    public final int deleted;
    /**
     * Line number of 1st deleted line.
     */
    public final int line0;
    /**
     * Line number of 1st inserted line.
     */
    public final int line1;

    /**
     * Cons an additional entry onto the front of an edit script OLD.
     * LINE0 and LINE1 are the first affected lines in the two files (origin 0).
     * DELETED is the number of lines deleted here from file 0.
     * INSERTED is the number of lines inserted here in file 1.
     * <p/>
     * If DELETED is 0 then LINE0 is the number of the line before
     * which the insertion was done; vice versa for INSERTED and LINE1.
     */
    public change(int line0, int line1, int deleted, int inserted, change old) {
      this.line0 = line0;
      this.line1 = line1;
      this.inserted = inserted;
      this.deleted = deleted;
      this.link = old;
      //System.err.println(line0+","+line1+","+inserted+","+deleted);
    }
  }

  /**
   * Data on one input file being compared.
   */

  class file_data {

    /**
     * Allocate changed array for the results of comparison.
     */
    void clear() {
      /* Allocate a flag for each line of each file, saying whether that line
	 is an insertion or deletion.
	 Allocate an extra element, always zero, at each end of each vector.
       */
      changed_flag = new boolean[buffered_lines + 2];
    }

    /**
     * Return equiv_count[I] as the number of lines in this file
     * that fall in equivalence class I.
     *
     * @return the array of equivalence class counts.
     */
    int[] equivCount() {
      int[] equiv_count = new int[equiv_max];
      for (int i = 0; i < buffered_lines; ++i)
        ++equiv_count[equivs[i]];
      return equiv_count;
    }

    /**
     * Discard lines that have no matches in another file.
     * <p/>
     * A line which is discarded will not be considered by the actual
     * comparison algorithm; it will be as if that line were not in the file.
     * The file's `realindexes' table maps virtual line numbers
     * (which don't count the discarded lines) into real line numbers;
     * this is how the actual comparison algorithm produces results
     * that are comprehensible when the discarded lines are counted.
     * <p/>
     * When we discard a line, we also mark it as a deletion or insertion
     * so that it will be printed in the output.
     *
     * @param f the other file
     */
    void discard_confusing_lines(file_data f) {
      clear();
      /* Set up table of which lines are going to be discarded. */
      final byte[] discarded = discardable(f.equivCount());

      /* Don't really discard the provisional lines except when they occur
         in a run of discardables, with nonprovisionals at the beginning
         and end.  */
      filterDiscards(discarded);

      /* Actually discard the lines. */
      discard(discarded);
    }

    /**
     * Mark to be discarded each line that matches no line of another file.
     * If a line matches many lines, mark it as provisionally discardable.
     *
     * @param counts The count of each equivalence number for the other file.
     * @return 0=nondiscardable, 1=discardable or 2=provisionally discardable
     *         for each line
     */

    private byte[] discardable(final int[] counts) {
      final int end = buffered_lines;
      final byte[] discards = new byte[end];
      final int[] equivs = this.equivs;
      int many = 5;
      int tem = end / 64;

      /* Multiply MANY by approximate square root of number of lines.
	 That is the threshold for provisionally discardable lines.  */
      while ((tem = tem >> 2) > 0)
        many *= 2;

      for (int i = 0; i < end; i++) {
        int nmatch;
        if (equivs[i] == 0)
          continue;
        nmatch = counts[equivs[i]];
        if (nmatch == 0)
          discards[i] = 1;
        else if (nmatch > many)
          discards[i] = 2;
      }
      return discards;
    }

    /**
     * Don't really discard the provisional lines except when they occur
     * in a run of discardables, with nonprovisionals at the beginning
     * and end.
     */

    private void filterDiscards(final byte[] discards) {
      final int end = buffered_lines;

      for (int i = 0; i < end; i++) {
        /* Cancel provisional discards not in middle of run of discards.  */
        if (discards[i] == 2)
          discards[i] = 0;
        else if (discards[i] != 0) {
          /* We have found a nonprovisional discard.  */
          int j;
          int length;
          int provisional = 0;

          /* Find end of this run of discardable lines.
             Count how many are provisionally discardable.  */
          for (j = i; j < end; j++) {
            if (discards[j] == 0)
              break;
            if (discards[j] == 2)
              ++provisional;
          }

          /* Cancel provisional discards at end, and shrink the run.  */
          while (j > i && discards[j - 1] == 2) {
            discards[--j] = 0;
            --provisional;
          }

          /* Now we have the length of a run of discardable lines
             whose first and last are not provisional.  */
          length = j - i;

          /* If 1/4 of the lines in the run are provisional,
             cancel discarding of all provisional lines in the run.  */
          if (provisional * 4 > length) {
            while (j > i)
              if (discards[--j] == 2)
                discards[j] = 0;
          } else {
            int consec;
            int minimum = 1;
            int tem = length / 4;

            /* MINIMUM is approximate square root of LENGTH/4.
               A subrun of two or more provisionals can stand
               when LENGTH is at least 16.
               A subrun of 4 or more can stand when LENGTH >= 64.  */
            while ((tem = tem >> 2) > 0)
              minimum *= 2;
            minimum++;

            /* Cancel any subrun of MINIMUM or more provisionals
               within the larger run.  */
            for (j = 0, consec = 0; j < length; j++)
              if (discards[i + j] != 2)
                consec = 0;
              else if (minimum == ++consec)
              /* Back up to start of subrun, to cancel it all.  */
                j -= consec;
              else if (minimum < consec)
                discards[i + j] = 0;

            /* Scan from beginning of run
               until we find 3 or more nonprovisionals in a row
               or until the first nonprovisional at least 8 lines in.
               Until that point, cancel any provisionals.  */
            for (j = 0, consec = 0; j < length; j++) {
              if (j >= 8 && discards[i + j] == 1)
                break;
              if (discards[i + j] == 2) {
                consec = 0;
                discards[i + j] = 0;
              } else if (discards[i + j] == 0)
                consec = 0;
              else
                consec++;
              if (consec == 3)
                break;
            }

            /* I advances to the last line of the run.  */
            i += length - 1;

            /* Same thing, from end.  */
            for (j = 0, consec = 0; j < length; j++) {
              if (j >= 8 && discards[i - j] == 1)
                break;
              if (discards[i - j] == 2) {
                consec = 0;
                discards[i - j] = 0;
              } else if (discards[i - j] == 0)
                consec = 0;
              else
                consec++;
              if (consec == 3)
                break;
            }
          }
        }
      }
    }

    /**
     * Actually discard the lines.
     *
     * @param discards flags lines to be discarded
     */
    private void discard(final byte[] discards) {
      final int end = buffered_lines;
      int j = 0;
      for (int i = 0; i < end; ++i)
        if (no_discards || discards[i] == 0) {
          undiscarded[j] = equivs[i];
          realindexes[j++] = i;
        } else
          changed_flag[1 + i] = true;
      nondiscarded_lines = j;
    }

    file_data(Object[] data, Hashtable h) {
      buffered_lines = data.length;

      equivs = new int[buffered_lines];
      undiscarded = new int[buffered_lines];
      realindexes = new int[buffered_lines];

      for (int i = 0; i < data.length; ++i) {
        Integer ir = (Integer) h.get(data[i]);
        if (ir == null)
          h.put(data[i], new Integer(equivs[i] = equiv_max++));
        else
          equivs[i] = ir.intValue();
      }
    }

    /**
     * Adjust inserts/deletes of blank lines to join changes
     * as much as possible.
     * <p/>
     * We do something when a run of changed lines include a blank
     * line at one end and have an excluded blank line at the other.
     * We are free to choose which blank line is included.
     * `compareseq' always chooses the one at the beginning,
     * but usually it is cleaner to consider the following blank line
     * to be the "change".  The only exception is if the preceding blank line
     * would join this change to other changes.
     *
     * @param f the file being compared against
     */

    void shift_boundaries(file_data f) {
      final boolean[] changed = changed_flag;
      final boolean[] other_changed = f.changed_flag;
      int i = 0;
      int j = 0;
      int i_end = buffered_lines;
      int preceding = -1;
      int other_preceding = -1;

      for (; ;) {
        int start, end, other_start;

        /* Scan forwards to find beginning of another run of changes.
           Also keep track of the corresponding point in the other file.  */

        while (i < i_end && !changed[1 + i]) {
          while (other_changed[1 + j++])
            /* Non-corresponding lines in the other file
               will count as the preceding batch of changes.  */
            other_preceding = j;
          i++;
        }

        if (i == i_end)
          break;

        start = i;
        other_start = j;

        for (; ;) {
          /* Now find the end of this run of changes.  */

          while (i < i_end && changed[1 + i]) i++;
          end = i;

          /* If the first changed line matches the following unchanged one,
       and this run does not follow right after a previous run,
       and there are no lines deleted from the other file here,
       then classify the first changed line as unchanged
       and the following line as changed in its place.  */

          /* You might ask, how could this run follow right after another?
       Only because the previous run was shifted here.  */

          if (end != i_end
            && equivs[start] == equivs[end]
            && !other_changed[1 + j]
            && end != i_end
            && !((preceding >= 0 && start == preceding)
            || (other_preceding >= 0
            && other_start == other_preceding))) {
            changed[1 + end] = true;
            changed[1 + start++] = false;
            ++i;
            /* Since one line-that-matches is now before this run
               instead of after, we must advance in the other file
               to keep in synch.  */
            ++j;
          } else
            break;
        }

        preceding = i;
        other_preceding = j;
      }
    }

    /**
     * Number of elements (lines) in this file.
     */
    final int buffered_lines;

    /**
     * Vector, indexed by line number, containing an equivalence code for
     * each line.  It is this vector that is actually compared with that
     * of another file to generate differences.
     */
    private final int[] equivs;

    /**
     * Vector, like the previous one except that
     * the elements for discarded lines have been squeezed out.
     */
    final int[] undiscarded;

    /**
     * Vector mapping virtual line numbers (not counting discarded lines)
     * to real ones (counting those lines).  Both are origin-0.
     */
    final int[] realindexes;

    /**
     * Total number of nondiscarded lines.
     */
    int nondiscarded_lines;

    /**
     * Array, indexed by real origin-1 line number,
     * containing true for a line that is an insertion or a deletion.
     * The results of comparison are stored here.
     */
    boolean[] changed_flag;

  }
}

static List<String> diff(Collection<String> a, Collection<String> b) {
  Set<String> set = asSet(b);
  List<String> l = new ArrayList();
  for (String s : a)
    if (!set.contains(s))
      l.add(s);
  return l;
}


static Set asSet(Object[] array) {
  HashSet set = new HashSet();
  for (Object o : array)
    if (o != null)
      set.add(o);
  return set;
}

static Set<String> asSet(String[] array) {
  TreeSet<String> set = new TreeSet<String>();
  for (String o : array)
    if (o != null)
      set.add(o);
  return set;
}

static Set<String> asSet(Collection<String> l) {
  TreeSet<String> set = new TreeSet<String>();
  for (String o : l)
    if (o != null)
      set.add(o);
  return set;
}

}