import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import java.net.*;
import java.io.*;
import javax.swing.*;
import java.util.regex.*;
import java.util.*;



import java.lang.reflect.*;
import java.math.*; // BigInteger
import java.text.DecimalFormat;
import java.lang.management.*; // for time measurement

/**
 JavaX runner version 18

 Changes to v17:
 -can run server-transpiled main programs for super-quick compilation
  (no local transpiling except for nested solvers or something)

 */

class _x18 {
  static final String version = "JavaX 18";

  static boolean verbose = false, translate = false, list = false, virtualizeTranslators = true;
  static String translateTo = null;
  static boolean preferCached = false, safeOnly = false, noID = false, noPrefetch = false;
  static List<String[]> mainTranslators = new ArrayList<String[]>();
  private static Map<Long, String> memSnippetCache = new HashMap<Long, String>();
  private static int processesStarted, compilations;

  // snippet ID -> md5
  private static HashMap<Long, String> prefetched = new HashMap<Long, String>();
  private static File virtCache;

  // doesn't work yet
  private static Map<String, Class<?>> programCache = new HashMap<String, Class<?>>();
  static boolean cacheTranslators = false;

  // this should work (caches transpiled translators)
  private static HashMap<Long, Object[]> translationCache = new HashMap<Long, Object[]>();
  static boolean cacheTranspiledTranslators = true;

  // which snippets are available pre-transpiled server-side?
  private static Set<Long> hasTranspiledSet = new HashSet<Long>();
  static boolean useServerTranspiled = true;

  static Object androidContext;
  static boolean android = isAndroid();

  public static void main(String[] args) throws Exception {
    File ioBaseDir = new File("."), inputDir = null, outputDir = null;
    String src = null;
    List<String> programArgs = new ArrayList<String>();

    for (int i = 0; i < args.length; i++) {
      String arg = args[i];

      if (arg.equals("-version")) {
        showVersion();
        return;
      }

      if (arg.equals("-sysprop")) {
        showSystemProperties();
        return;
      }

      if (arg.equals("-v") || arg.equals("-verbose"))
        verbose = true;
      else if (arg.equals("-finderror"))
        verbose = true;
      else if (arg.equals("-offline") || arg.equalsIgnoreCase("-prefercached"))
        preferCached = true;
      else if (arg.equals("-novirt"))
        virtualizeTranslators = false;
      else if (arg.equals("-safeonly"))
        safeOnly = true;
      else if (arg.equals("-noid"))
        noID = true;
      else if (arg.equals("-nocachetranspiled"))
        cacheTranspiledTranslators = false;
      else if (arg.equals("-localtranspile"))
        useServerTranspiled = false;
      else if (arg.equals("translate"))
        translate = true;
      else if (arg.equals("list")) {
        list = true;
        virtualizeTranslators = false; // so they are silenced
      } else if (arg.equals("run")) {
        // it's the default command anyway
      } else if (arg.startsWith("input="))
        inputDir = new File(arg.substring(6));
      else if (arg.startsWith("output="))
        outputDir = new File(arg.substring(7));
      else if (arg.equals("with"))
        mainTranslators.add(new String[] {args[++i], null});
      else if (translate && arg.equals("to"))
        translateTo = args[++i];
      else if (src == null) {
        //System.out.println("src=" + arg);
        src = arg;
      } else
        programArgs.add(arg);
    }

    cleanCache();

    if (useServerTranspiled)
      noPrefetch = true;

    if (src == null) src = ".";

    // Might actually want to write to 2 disk caches (global/per program).
    if (virtualizeTranslators && !preferCached)
      virtCache = TempDirMaker_make();

    if (inputDir != null) {
      ioBaseDir = TempDirMaker_make();
      System.out.println("Taking input from: " + inputDir.getAbsolutePath());
      System.out.println("Output is in: " + new File(ioBaseDir, "output").getAbsolutePath());
      copyInput(inputDir, new File(ioBaseDir, "input"));
    }

    javaxmain(src, ioBaseDir, translate, list, programArgs.toArray(new String[programArgs.size()]));

    if (outputDir != null) {
      copyInput(new File(ioBaseDir, "output"), outputDir);
      System.out.println("Output copied to: " + outputDir.getAbsolutePath());
    }

    if (verbose) {
      // print stats
      System.out.println("Processes started: " + processesStarted + ", compilations: " + compilations);
    }
  }

  public static void javaxmain(String src, File ioDir, boolean translate, boolean list,
                               String[] args) throws Exception {
    List<File> libraries = new ArrayList<File>();
    File X = transpileMain(src, libraries);
    if (X == null)
      return;

    // list or run

    if (translate) {
      File to = X;
      if (translateTo != null)
        if (new File(translateTo).isDirectory())
          to = new File(translateTo, "main.java");
        else
          to = new File(translateTo);
      if (to != X)
        copy(new File(X, "main.java"), to);
      System.out.println("Program translated to: " + to.getAbsolutePath());
    } else if (list)
      System.out.println(loadTextFile(new File(X, "main.java").getPath(), null));
    else
      javax2(X, ioDir, false, false, libraries, args, null);
  }

  static File transpileMain(String src, List<File> libraries) throws Exception {
    File srcDir;
    boolean isTranspiled = false;
    if (isSnippetID(src)) {
      prefetch(src);
      long id = parseSnippetID(src);
      srcDir = loadSnippetAsMainJava(src);
      if (hasTranspiledSet.contains(id)) {
        System.err.println("Trying pretranspiled main program: #" + id);
        String transpiledSrc = getServerTranspiled("#" + id);
        if (!transpiledSrc.isEmpty()) {
          srcDir = TempDirMaker_make();
          saveTextFile(new File(srcDir, "main.java").getPath(), transpiledSrc);
          isTranspiled = true;
          //translationCache.put(id, new Object[] {srcDir, libraries});
        }
      }
    } else {
      srcDir = new File(src);

      // if the argument is a file, it is assumed to be main.java
      if (srcDir.isFile()) {
        srcDir = TempDirMaker_make();
        copy(new File(src), new File(srcDir, "main.java"));
      }

      if (!new File(srcDir, "main.java").exists()) {
        showVersion();
        System.out.println("No main.java found, exiting");
        return null;
      }
    }

    // translate

    File X = srcDir;

    if (!isTranspiled) {
      X = topLevelTranslate(X, libraries);
      System.err.println("Translated " + src);

      // save prefetch data
      if (isSnippetID(src))
        savePrefetchData(src);
    }
    return X;
  }

  private static void prefetch(String mainSnippetID) throws IOException {
    if (noPrefetch) return;

    long mainID = parseSnippetID(mainSnippetID);
    String s = mainID + " " + loadTextFile(new File(userHome(), ".tinybrain/prefetch/" + mainID + ".txt").getPath(), "");
    String[] ids = s.trim().split(" ");
    if (ids.length > 1) {
      String url = "http://tinybrain.de:8080/tb-int/prefetch.php?ids=" + URLEncoder.encode(s, "UTF-8");
      String data = loadPage(new URL(url));
      String[] split = data.split(" ");
      if (split.length == ids.length)
        for (int i = 0; i < ids.length; i++)
          prefetched.put(parseSnippetID(ids[i]), split[i]);
    }
  }

  static String _userHome;
  static String userHome() {
    if (_userHome == null) {
      if (android)
        _userHome = ((File) call(androidContext, "getFilesDir")).getAbsolutePath();
      else
        _userHome = System.getProperty("user.home");
      System.out.println("userHome: " + _userHome);
    }
    return _userHome;
  }

  private static void savePrefetchData(String mainSnippetID) throws IOException {
    List<String> ids = new ArrayList<String>();
    long mainID = parseSnippetID(mainSnippetID);

    for (long id : memSnippetCache.keySet())
      if (id != mainID)
        ids.add(String.valueOf(id));

    saveTextFile(new File(userHome(),".tinybrain/prefetch/" + mainID + ".txt").getPath(), join(" ", ids));
  }

  static File topLevelTranslate(File srcDir, List<File> libraries_out) throws Exception {
    File X = srcDir;
    X = applyTranslators(X, mainTranslators, libraries_out); // translators supplied on command line (unusual)

    // actual inner translation of the JavaX source
    X = defaultTranslate(X, libraries_out);
    return X;
  }

  private static File defaultTranslate(File x, List<File> libraries_out) throws Exception {
    x = luaPrintToJavaPrint(x);
    x = repeatAutoTranslate(x, libraries_out);
    return x;
  }

  private static File repeatAutoTranslate(File x, List<File> libraries_out) throws Exception {
    while (true) {
      File y = autoTranslate(x, libraries_out);
      if (y == x)
        return x;
      x = y;
    }
  }

  private static File autoTranslate(File x, List<File> libraries_out) throws Exception {
    String main = loadTextFile(new File(x, "main.java").getPath(), null);
    List<String> lines = toLines(main);
    List<String[]> translators = findTranslators(lines);
    if (translators.isEmpty())
      return x;

    main = fromLines(lines);
    File newDir = TempDirMaker_make();
    saveTextFile(new File(newDir, "main.java").getPath(), main);
    return applyTranslators(newDir, translators, libraries_out);
  }

  private static List<String[]> findTranslators(List<String> lines) {
    List<String[]> translators = new ArrayList<String[]>();
    Pattern pattern = Pattern.compile("^!([0-9# \t]+)");
    Pattern pArgs = Pattern.compile("^\\s*\\((.*)\\)");
    for (ListIterator<String> iterator = lines.listIterator(); iterator.hasNext(); ) {
      String line = iterator.next();
      line = line.trim();
      Matcher matcher = pattern.matcher(line);
      if (matcher.find()) {
        String[] t = matcher.group(1).split("[ \t]+");
        String rest = line.substring(matcher.end());
        String arg = null;
        if (t.length == 1) {
          Matcher mArgs = pArgs.matcher(rest);
          if (mArgs.find())
            arg = mArgs.group(1);
        }
        for (String transi : t)
          translators.add(new String[]{transi, arg});
        iterator.remove();
      }
    }
    return translators;
  }

  public static List<String> toLines(String s) {
    List<String> lines = new ArrayList<String>();
    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;
  }

  public static String fromLines(List<String> lines) {
    StringBuilder buf = new StringBuilder();
    for (String line : lines) {
      buf.append(line).append('\n');
    }
    return buf.toString();
  }

  private static File applyTranslators(File x, List<String[]> translators, List<File> libraries_out) throws Exception {
    for (String[] translator : translators)
      x = applyTranslator(x, translator[0], translator[1], libraries_out);
    return x;
  }

  // also takes a library
  private static File applyTranslator(File x, String translator, String arg, List<File> libraries_out) throws Exception {
    if (verbose)
      System.out.println("Using translator " + translator + " on sources in " + x.getPath());

    File newDir = runTranslatorOnInput(translator, null, arg, x, !verbose, libraries_out);

    if (!new File(newDir, "main.java").exists()) {
      throw new Exception("Translator " + translator + " did not generate main.java");
      // TODO: show translator output
    }
    if (verbose)
      System.out.println("Translated with " + translator + " from " + x.getPath() + " to " + newDir.getPath());
    x = newDir;
    return x;
  }

  private static File luaPrintToJavaPrint(File x) throws IOException {
    File newDir = TempDirMaker_make();
    String code = loadTextFile(new File(x, "main.java").getPath(), null);
    code = luaPrintToJavaPrint(code);
    if (verbose)
      System.out.println(code);
    saveTextFile(new File(newDir, "main.java").getPath(), code);
    return newDir;
  }

  public static String luaPrintToJavaPrint(String code) {
    return ("\n" + code).replaceAll(
      "(\n\\s*)print (\".*\")",
      "$1System.out.println($2);").substring(1);
  }

  public static File loadSnippetAsMainJava(String snippetID) throws IOException {
    checkProgramSafety(snippetID);
    File srcDir = TempDirMaker_make();
    saveTextFile(new File(srcDir, "main.java").getPath(), loadSnippet(snippetID));
    return srcDir;
  }

  public static File loadSnippetAsMainJavaVerified(String snippetID, String hash) throws IOException {
    checkProgramSafety(snippetID);
    File srcDir = TempDirMaker_make();
    saveTextFile(new File(srcDir, "main.java").getPath(), loadSnippetVerified(snippetID, hash));
    return srcDir;
  }

  /** returns output dir */
  private static File runTranslatorOnInput(String snippetID, String hash, String arg, File input,
                                           boolean silent,
                                           List<File> libraries_out) throws Exception {
    long id = parseSnippetID(snippetID);
    File libraryFile = DiskSnippetCache_getLibrary(id);
    if (libraryFile != null) {
      loadLibrary(snippetID, libraries_out, libraryFile);
      return input;
    }

    String[] args = arg != null ? new String[]{arg} : new String[0];

    File srcDir = hash == null ? loadSnippetAsMainJava(snippetID)
      : loadSnippetAsMainJavaVerified(snippetID, hash);
    long mainJavaSize = new File(srcDir, "main.java").length();

    if (mainJavaSize == 0) { // no text in snippet? assume it's a library
      loadLibrary(snippetID, libraries_out, libraryFile);
      return input;
    }

    List<File> libraries = new ArrayList<File>();
    Object[] cached = translationCache.get(id);
    if (cached != null) {
      //System.err.println("Taking translator " + snippetID + " from cache!");
      srcDir = (File) cached[0];
      libraries = (List<File>) cached[1];
    } else if (hasTranspiledSet.contains(id)) {
      System.err.println("Trying pretranspiled translator: #" + snippetID);
      String transpiledSrc = getServerTranspiled(snippetID);
      if (!transpiledSrc.isEmpty()) {
        srcDir = TempDirMaker_make();
        saveTextFile(new File(srcDir, "main.java").getPath(), transpiledSrc);
        translationCache.put(id, cached = new Object[] {srcDir, libraries});
      }
    }

    File ioBaseDir = TempDirMaker_make();

    /*Class<?> mainClass = programCache.get("" + parseSnippetID(snippetID));
    if (mainClass != null)
      return runCached(ioBaseDir, input, args);*/
    // Doesn't work yet because virtualized directories are hardcoded in translator...

    if (cached == null) {
      System.err.println("Translating translator #" + id);
      srcDir = defaultTranslate(srcDir, libraries);
      System.err.println("Translated translator #" + id);
      if (cacheTranspiledTranslators)
        translationCache.put(id, new Object[]{srcDir, libraries});
    }

    boolean runInProcess = false;

    if (virtualizeTranslators) {
      if (verbose) System.out.println("Virtualizing translator");

      //srcDir = applyTranslator(srcDir, "#2000351"); // I/O-virtualize the translator
      // that doesn't work because it recurses infinitely...

      // So we do it right here:
      String s = loadTextFile(new File(srcDir, "main.java").getPath(), null);
      s = s.replaceAll("new\\s+File\\(", "virtual.newFile(");
      s = s.replaceAll("new\\s+FileInputStream\\(", "virtual.newFileInputStream(");
      s = s.replaceAll("new\\s+FileOutputStream\\(", "virtual.newFileOutputStream(");
      s += "\n\n" + loadSnippet("#2000355"); // load class virtual

      // change baseDir
      s = s.replace("virtual_baseDir = \"\";",
        "virtual_baseDir = " + javaQuote(ioBaseDir.getAbsolutePath()) + ";");

      // forward snippet cache (virtualized one)
      File dir = virtCache != null ? virtCache : DiskSnippetCache_dir;
      s = s.replace("static File DiskSnippetCache_dir;",
        "static File DiskSnippetCache_dir = new File(" + javaQuote(dir.getAbsolutePath()) + ");");
      s = s.replace("static boolean preferCached = false;", "static boolean preferCached = true;");

      if (verbose) {
        System.out.println("==BEGIN VIRTUALIZED TRANSLATOR==");
        System.out.println(s);
        System.out.println("==END VIRTUALIZED TRANSLATOR==");
      }
      srcDir = TempDirMaker_make();
      saveTextFile(new File(srcDir, "main.java").getPath(), s);

      // TODO: silence translator also
      runInProcess = true;
    }

    return runJavaX(ioBaseDir, srcDir, input, silent, runInProcess, libraries,
      args, cacheTranslators ? "" + id : null);
  }

  private static String getServerTranspiled(String snippetID) throws IOException {
    long id = parseSnippetID(snippetID);
    URL url = new URL("http://tinybrain.de:8080/tb-int/get-transpiled.php?raw=1&id=" + id);
    return loadPage(url);
  }

  static void checkProgramSafety(String snippetID) throws IOException {
    if (!safeOnly) return;
    URL url = new URL("http://tinybrain.de:8080/tb-int/is-javax-safe.php?id=" + parseSnippetID(snippetID));
    String text = loadPage(url);
    if (!text.startsWith("{\"safe\":\"1\"}"))
      throw new RuntimeException("Translator not safe: #" + parseSnippetID(snippetID));
  }

  private static void loadLibrary(String snippetID, List<File> libraries_out, File libraryFile) throws IOException {
    if (verbose)
      System.out.println("Assuming " + snippetID + " is a library.");

    if (libraryFile == null) {
      byte[] data = loadDataSnippetImpl(snippetID);
      DiskSnippetCache_putLibrary(parseSnippetID(snippetID), data);
      libraryFile = DiskSnippetCache_getLibrary(parseSnippetID(snippetID));
    }

    if (!libraries_out.contains(libraryFile))
      libraries_out.add(libraryFile);
  }

  private static byte[] loadDataSnippetImpl(String snippetID) throws IOException {
    byte[] data;
    try {
      URL url = new URL("http://eyeocr.sourceforge.net/filestore/filestore.php?cmd=serve&file=blob_"
        + parseSnippetID(snippetID) + "&contentType=application/binary");
      System.err.println("Loading library: " + url);
      data = loadBinaryPage(url.openConnection());
      if (verbose)
        System.err.println("Bytes loaded: " + data.length);
    } catch (FileNotFoundException e) {
      throw new IOException("Binary snippet #" + snippetID + " not found or not public");
    }
    return data;
  }

  /** returns output dir */
  private static File runJavaX(File ioBaseDir, File originalSrcDir, File originalInput,
                               boolean silent, boolean runInProcess,
                               List<File> libraries, String[] args, String cacheAs) throws Exception {
    File srcDir = new File(ioBaseDir, "src");
    File inputDir = new File(ioBaseDir, "input");
    File outputDir = new File(ioBaseDir, "output");
    copyInput(originalSrcDir, srcDir);
    copyInput(originalInput, inputDir);
    javax2(srcDir, ioBaseDir, silent, runInProcess, libraries, args, cacheAs);
    return outputDir;
  }

  private static void copyInput(File src, File dst) throws IOException {
    copyDirectory(src, dst);
  }

  public static boolean hasFile(File inputDir, String name) {
    return new File(inputDir, name).exists();
  }

  public static void copyDirectory(File src, File dst) throws IOException {
    if (verbose) System.out.println("Copying " + src.getAbsolutePath() + " to " + dst.getAbsolutePath());
    dst.mkdirs();
    File[] files = src.listFiles();
    if (files == null) return;
    for (File file : files) {
      File dst1 = new File(dst, file.getName());
      if (file.isDirectory())
        copyDirectory(file, dst1);
      else {
        if (verbose) System.out.println("Copying " + file.getAbsolutePath() + " to " + dst1.getAbsolutePath());
        copy(file, dst1);
      }
    }
  }

  /** Quickly copy a file without a progress bar or any other fancy GUI... :) */
  public static void copy(File src, File dest) throws IOException {
    FileInputStream inputStream = newFileInputStream(src);
    FileOutputStream outputStream = newFileOutputStream(dest);
    try {
      copy(inputStream, outputStream);
      inputStream.close();
    } finally {
      outputStream.close();
    }
  }

  static Object call(Object o, String method, Object... args) {
    try {
      Method m = call_findMethod(o, method, args, false);
      m.setAccessible(true);
      return m.invoke(o, args);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  static Object call(Class c, String method, Object... args) {
    try {
      Method m = call_findStaticMethod(c, method, args, false);
      m.setAccessible(true);
      return m.invoke(null, args);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  static Method call_findStaticMethod(Class c, String method, Object[] args, boolean debug) {
    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 || types[i].isInstance(args[i]))) {
        if (debug)
          System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
        return false;
      }
    return true;
  }

  private static FileInputStream newFileInputStream(File f) throws FileNotFoundException {
    /*if (androidContext != null)
      return (FileInputStream) call(androidContext,
        "openFileInput", f.getPath());
    else*/
    return new FileInputStream(f);
  }

  private static FileOutputStream newFileOutputStream(File f) throws FileNotFoundException {
    /*if (androidContext != null)
      return (FileOutputStream) call(androidContext,
        "openFileOutput", f.getPath(), 0);
    else*/
    return new FileOutputStream(f);
  }

  public static void copy(InputStream in, OutputStream out) throws IOException {
    byte[] buf = new byte[65536];
    while (true) {
      int n = in.read(buf);
      if (n <= 0) return;
      out.write(buf, 0, n);
    }
  }

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

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

  /** writes safely (to temp file, then rename) */
  public static void saveBinaryFile(String fileName, byte[] contents) throws IOException {
    File file = new File(fileName);
    File parentFile = file.getParentFile();
    if (parentFile != null)
      parentFile.mkdirs();
    String tempFileName = fileName + "_temp";
    FileOutputStream fileOutputStream = newFileOutputStream(new File(tempFileName));
    fileOutputStream.write(contents);
    fileOutputStream.close();
    if (file.exists() && !file.delete())
      throw new IOException("Can't delete " + fileName);

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

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

    FileInputStream fileInputStream = newFileInputStream(new File(fileName));
    InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, charsetForTextFiles);
    return loadTextFile(inputStreamReader, (int) new File(fileName).length());
  }

  public static String loadTextFile(Reader reader, int length) throws IOException {
    try {
      char[] chars = new char[length];
      int n = reader.read(chars);
      return new String(chars, 0, n);
    } finally {
      reader.close();
    }
  }

  static File DiskSnippetCache_dir;

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

  // Data files are immutable, use centralized cache
  public static synchronized File DiskSnippetCache_getLibrary(long snippetID) throws IOException {
    File file = new File(getGlobalCache(), "data_" + snippetID + ".jar");
    if (verbose)
      System.out.println("Checking data cache: " + file.getPath());
    return file.exists() ? file : null;
  }

  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 synchronized void DiskSnippetCache_putLibrary(long snippetID, byte[] data) throws IOException {
    saveBinaryFile(new File(getGlobalCache(), "data_" + snippetID).getPath() + ".jar", data);
  }

  public static File DiskSnippetCache_getDir() {
    return DiskSnippetCache_dir;
  }

  public static void initSnippetCache() {
    if (DiskSnippetCache_dir == null)
      initDiskSnippetCache(getGlobalCache());
  }

  private static File getGlobalCache() {
    File file = new File(userHome(), ".tinybrain/snippet-cache");
    file.mkdirs();
    return file;
  }

  public static String loadSnippetVerified(String snippetID, String hash) throws IOException {
    String text = loadSnippet(snippetID);
    String realHash = getHash(text.getBytes("UTF-8"));
    if (!realHash.equals(hash)) {
      String msg;
      if (hash.isEmpty())
        msg = "Here's your hash for " + snippetID + ", please put in your program: " + realHash;
      else
        msg = "Hash mismatch for " + snippetID + ": " + realHash + " (new) vs " + hash + " - has tinybrain.de been hacked??";
      throw new RuntimeException(msg);
    }
    return text;
  }

  public static String getHash(byte[] data) {
    return bytesToHex(getFullFingerprint(data));
  }

  public static byte[] getFullFingerprint(byte[] data) {
    try {
      return MessageDigest.getInstance("MD5").digest(data);
    } catch (NoSuchAlgorithmException e) {
      throw new RuntimeException(e);
    }
  }

  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();
  }

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

  public static long parseSnippetID(String snippetID) {
    return Long.parseLong(shortenSnippetID(snippetID));
  }

  private 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 snippetID;
  }

  public static boolean isSnippetID(String snippetID) {
    snippetID = shortenSnippetID(snippetID);
    return isInteger(snippetID) && Long.parseLong(snippetID) != 0;
  }

  public static boolean isInteger(String s) {
    return Pattern.matches("\\-?\\d+", s);
  }

  public static String loadSnippet(long snippetID) throws IOException {
    String text = memSnippetCache.get(snippetID);
    if (text != null)
      return text;

    initSnippetCache();
    text = DiskSnippetCache_get(snippetID);
    if (preferCached && text != null)
      return text;

    String md5 = text != null ? md5(text) : "-";
    if (text != null) {
      String hash = prefetched.get(snippetID);
      if (hash != null) {
        if (md5.equals(hash)) {
          memSnippetCache.put(snippetID, text);
          return text;
        } else
          prefetched.remove(snippetID); // (maybe this is not necessary)
      }
    }

    try {
      /*URL url = new URL("http://tinybrain.de:8080/getraw.php?id=" + snippetID);
      text = loadPage(url);*/
      String theURL = "http://tinybrain.de:8080/getraw.php?id=" + snippetID + "&getmd5=1&utf8=1&usetranspiled=1";
      if (text != null) {
        //System.err.println("MD5: " + md5);
        theURL += "&md5=" + md5;
      }
      URL url = new URL(theURL);
      String page = loadPage(url);

      // parse & drop transpilation flag available line
      int i = page.indexOf('\n');
      boolean hasTranspiled = page.substring(0, i).trim().equals("1");
      if (hasTranspiled)
        hasTranspiledSet.add(snippetID);
      else
        hasTranspiledSet.remove(snippetID);
      page = page.substring(i+1);

      if (page.startsWith("==*#*==")) {
        // same, keep text
        //System.err.println("Snippet unchanged, keeping.");
      } else {
        // drop md5 line
        i = page.indexOf('\n');
        String hash = page.substring(0, i).trim();
        text = page.substring(i+1);

        String myHash = md5(text);
        if (myHash.equals(hash)) {
          //System.err.println("Hash match: " + hash);
        } else
          System.err.println("Hash mismatch");
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
      throw new IOException("Snippet #" + snippetID + " not found or not public");
    }

    memSnippetCache.put(snippetID, text);

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

    return text;
  }

  private static String md5(String text) {
    try {
      return bytesToHex(md5impl(text.getBytes("UTF-8"))); // maybe different than the way PHP does it...
    } catch (UnsupportedEncodingException e) {
      throw new RuntimeException(e);
    }
  }

  public static byte[] md5impl(byte[] data) {
    try {
      return MessageDigest.getInstance("MD5").digest(data);
    } catch (NoSuchAlgorithmException e) {
      throw new RuntimeException(e);
    }
  }

  private static String loadPage(URL url) throws IOException {
    System.err.println("Loading: " + url.toExternalForm());
    URLConnection con = url.openConnection();
    return loadPage(con, url);
  }

  public static String loadPage(URLConnection con, URL url) throws IOException {
    setHeaders(con);
    String contentType = con.getContentType();
    if (contentType == null)
      throw new IOException("Page could not be read: " + url);
    //Log.info("Content-Type: " + contentType);
    String charset = guessCharset(contentType);
    //System.err.println("Charset: " + charset);
    Reader r = new InputStreamReader(con.getInputStream(), charset);
    StringBuilder buf = new StringBuilder();
    while (true) {
      int ch = r.read();
      if (ch < 0)
        break;
      //Log.info("Chars read: " + buf.length());
      buf.append((char) ch);
    }
    return buf.toString();
  }

  public static byte[] loadBinaryPage(URLConnection con) throws IOException {
    setHeaders(con);
    return loadBinaryPage_noHeaders(con);
  }

  private static byte[] loadBinaryPage_noHeaders(URLConnection con) throws IOException {
    ByteArrayOutputStream buf = new ByteArrayOutputStream();
    InputStream inputStream = con.getInputStream();
    while (true) {
      int ch = inputStream.read();
      if (ch < 0)
        break;
      buf.write(ch);
    }
    inputStream.close();
    return buf.toByteArray();
  }

  private static void setHeaders(URLConnection con) throws IOException {
    String computerID = getComputerID();
    if (computerID != null)
      con.setRequestProperty("X-ComputerID", computerID);
  }

  public static String guessCharset(String contentType) {
    Pattern p = Pattern.compile("text/html;\\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";
  }

  /** runs a transpiled set of sources */
  public static void javax2(File srcDir, File ioBaseDir, boolean silent, boolean runInProcess,
                            List<File> libraries, String[] args, String cacheAs) throws Exception {
    if (android)
      javax2android(srcDir, args);
    else {
      File classesDir = TempDirMaker_make();
      String javacOutput = compileJava(srcDir, libraries, classesDir);

      // run

      if (verbose) System.out.println("Running program (" + srcDir.getAbsolutePath()
        + ") on io dir " + ioBaseDir.getAbsolutePath() + (runInProcess ? "[in-process]" : "") + "\n");
      runProgram(javacOutput, classesDir, ioBaseDir, silent, runInProcess, libraries, args, cacheAs);
    }
  }

  static void javax2android(File srcDir, String[] args) throws Exception {
    // TODO: optimize if it's a loaded snippet anyway
    URL url = new URL("http://tinybrain.de:8080/dexcompile.php");
    URLConnection conn = url.openConnection();
    String postData = "src=" + URLEncoder.encode(loadTextFile(new File(srcDir, "main.java").getPath(), null), "UTF-8");
    byte[] dexData = doPostBinary(postData, conn, url);
    if (!isDex(dexData))
      throw new RuntimeException("Dex generation error: " + dexData.length + " bytes - " + new String(dexData, "UTF-8"));
    System.out.println("Dex loaded: " + dexData.length + "b");

    File dexDir = TempDirMaker_make();
    File dexFile = new File(dexDir, System.currentTimeMillis() + ".dex");
    File dexOutputDir = TempDirMaker_make();

    System.out.println("Saving dex to: " + dexDir.getAbsolutePath());
    try {
      saveBinaryFile(dexFile.getPath(), dexData);
    } catch (Throwable e) {
      System.out.println("Whoa!");
      throw new RuntimeException(e);
    }

    System.out.println("Getting parent class loader.");
    ClassLoader parentClassLoader =
      //ClassLoader.getSystemClassLoader(); // does not find support jar
      //getClass().getClassLoader(); // Let's try this...
      _x18.class.getClassLoader().getParent(); // XXX !

    System.out.println("Making DexClassLoader.");
    //DexClassLoader classLoader = new DexClassLoader(dexFile.getAbsolutePath(), dexOutputDir.getAbsolutePath(), null,
    //  parentClassLoader);
    Class dcl = Class.forName("dalvik.system.DexClassLoader");
    Object classLoader = dcl.getConstructors()[0].newInstance(dexFile.getAbsolutePath(), dexOutputDir.getAbsolutePath(), null,
      parentClassLoader);

    System.out.println("Loading main class.");
    //Class<?> theClass = classLoader.loadClass(mainClassName);
    Class<?> theClass = (Class<?>) call(classLoader, "loadClass", "main");

    System.out.println("Main class loaded.");
    try {
      set(theClass, "androidContext", androidContext);
    } catch (Throwable e) {}

    Method main = null;
    try {
      main = call_findStaticMethod(theClass, "main", new Object[]{androidContext}, false);
    } catch (RuntimeException e) {
    }

    System.out.println("main method for " + androidContext + " of " + theClass + ": " + main);

    if (main != null) {
      // old style main program that returns a View
      System.out.println("Calling main (old-style)");
      Object view = main.invoke(null, androidContext);
      System.out.println("Calling setContentView with " + view);
      call(Class.forName("main"), "setContentViewInUIThread", view);
      //call(androidContext, "setContentView", view);
      System.out.println("Done.");
    } else {
      System.out.println("New-style main method running.\n\n====\n");
      runMainMethod(args, theClass);
    }
  }

  static byte[] DEX_FILE_MAGIC = { 0x64, 0x65, 0x78, 0x0a, 0x30, 0x33, 0x35, 0x00 };

  static boolean isDex(byte[] dexData) {
    if (dexData.length < DEX_FILE_MAGIC.length) return false;
    for (int i = 0; i < DEX_FILE_MAGIC.length; i++)
      if (dexData[i] != DEX_FILE_MAGIC[i])
        return false;
    return true;
  }

  static byte[] doPostBinary(String urlParameters, URLConnection conn, URL url) throws IOException {
    // connect and do POST
    setHeaders(conn);
    conn.setDoOutput(true);

    OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
    writer.write(urlParameters);
    writer.flush();

    byte[] contents = loadBinaryPage_noHeaders(conn);
    writer.close();
    return contents;
  }

  static String compileJava(File srcDir, List<File> libraries, File classesDir) throws IOException {
    ++compilations;

    // collect sources

    List<File> sources = new ArrayList<File>();
    if (verbose) System.out.println("Scanning for sources in " + srcDir.getPath());
    scanForSources(srcDir, sources, true);
    if (sources.isEmpty())
      throw new IOException("No sources found");

    // compile

    File optionsFile = File.createTempFile("javax", "");
    if (verbose) System.out.println("Compiling " + sources.size() + " source(s) to " + classesDir.getPath());
    String options = "-d " + bashQuote(classesDir.getPath());
    writeOptions(sources, libraries, optionsFile, options);
    classesDir.mkdirs();
    return invokeJavac(optionsFile);
  }

  private static void runProgram(String javacOutput, File classesDir, File ioBaseDir,
                                 boolean silent, boolean runInProcess,
                                 List<File> libraries, String[] args, String cacheAs) throws Exception {
    // print javac output if compile failed and it hasn't been printed yet
    boolean didNotCompile = !didCompile(classesDir);
    if (verbose || didNotCompile)
      System.out.println(javacOutput);
    if (didNotCompile)
      return;

    if (runInProcess
      || (ioBaseDir.getAbsolutePath().equals(new File(".").getAbsolutePath()) && !silent)) {
      runProgramQuick(classesDir, libraries, args, cacheAs);
      return;
    }

    boolean echoOK = false;
    // TODO: add libraries to class path
    String bashCmd = "(cd " + bashQuote(ioBaseDir.getAbsolutePath()) + " && (java -cp "
      + bashQuote(classesDir.getAbsolutePath()) + " main" + (echoOK ? "; echo ok" : "") + "))";
    if (verbose) System.out.println(bashCmd);
    String output = backtick(bashCmd);
    if (verbose || !silent)
      System.out.println(output);
  }

  static boolean didCompile(File classesDir) {
    return hasFile(classesDir, "main.class");
  }

  private static void runProgramQuick(File classesDir, List<File> libraries,
                                      String[] args, String cacheAs) throws Exception {
    // collect urls
    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 JavaX main class
    Class<?> mainClass = classLoader.loadClass("main");

    if (cacheAs != null)
      programCache.put(cacheAs, mainClass);

    runMainMethod(args, mainClass);
  }


  static void runMainMethod(Object args, Class<?> mainClass) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
    Method main = mainClass.getMethod("main", String[].class);
    main.invoke(null, args);
  }

  private static String invokeJavac(File optionsFile) throws IOException {
    String output;
    try {
      output = invokeEcj(optionsFile);
    } catch (Exception e) {
      if (verbose) {
        System.err.println("ecj not found or misconfigured - using javac");
        e.printStackTrace();
      }
      output = backtick("javac " + bashQuote("@" + optionsFile.getPath()));
    }
    if (verbose) System.out.println(output);
    return output;
  }

  // throws ClassNotFoundException if ecj is not in classpath
  static String invokeEcj(File optionsFile) throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
    Class batchCompiler = getEclipseCompiler();

    StringWriter writer = new StringWriter();
    PrintWriter printWriter = new PrintWriter(writer);

    // add more eclipse options in the line below

    String[] args = { "@" + optionsFile.getPath(),
      "-source", "1.7",
      "-nowarn"
    };
    Method compile = batchCompiler.getDeclaredMethod("compile", args.getClass(), PrintWriter.class, PrintWriter.class,
      Class.forName("org.eclipse.jdt.core.compiler.CompilationProgress"));
    compile.invoke(null, args, printWriter, printWriter, null);
    return writer.toString();
  }

  static Class<?> getEclipseCompiler() throws ClassNotFoundException {
    return Class.forName("org.eclipse.jdt.core.compiler.batch.BatchCompiler");
  }

  private static void writeOptions(List<File> sources, List<File> libraries,
                                   File optionsFile, String moreOptions) throws IOException {
    FileWriter writer = new FileWriter(optionsFile);
    for (File source : sources)
      writer.write(bashQuote(source.getPath()) + " ");
    if (!libraries.isEmpty()) {
      List<String> cp = new ArrayList<String>();
      for (File lib : libraries)
        cp.add(lib.getAbsolutePath());
      writer.write("-cp " + bashQuote(join(File.pathSeparator, cp)) + " ");
    }
    writer.write(moreOptions);
    writer.close();
  }

  static void scanForSources(File source, List<File> sources, boolean topLevel) {
    if (source.isFile() && source.getName().endsWith(".java"))
      sources.add(source);
    else if (source.isDirectory() && !isSkippedDirectoryName(source.getName(), topLevel)) {
      File[] files = source.listFiles();
      for (File file : files)
        scanForSources(file, sources, false);
    }
  }

  private static boolean isSkippedDirectoryName(String name, boolean topLevel) {
    if (topLevel) return false; // input or output ok as highest directory (intentionally specified by user, not just found by a directory scan in which case we probably don't want it. it's more like heuristics actually.)
    return name.equalsIgnoreCase("input") || name.equalsIgnoreCase("output");
  }

  public static String backtick(String cmd) throws IOException {
    ++processesStarted;
    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 {
      saveTextFile(scriptFile.getPath(), command);
      String[] command2;
      if (isWindows())
        command2 = new String[] { scriptFile.getPath() };
      else
        command2 = new String[] { "/bin/bash", scriptFile.getPath() };
      Process process = Runtime.getRuntime().exec(command2);
      try {
        process.waitFor();
      } catch (InterruptedException e) {
        throw new RuntimeException(e);
      }
      process.exitValue();
      return loadTextFile(outFile.getPath(), "");
    } finally {
      scriptFile.delete();
    }
  }

  /** possibly improvable */
  public static String javaQuote(String text) {
    return bashQuote(text);
  }

  /** possibly improvable */
  public static String bashQuote(String text) {
    if (text == null) return null;
    return "\"" + text
      .replace("\\", "\\\\")
      .replace("\"", "\\\"")
      .replace("\n", "\\n")
      .replace("\r", "\\r") + "\"";
  }

  public final static String charsetForTextFiles = "UTF8";

  static long TempDirMaker_lastValue;

  public static File TempDirMaker_make() {
    File dir = new File(userHome(), ".javax/" + TempDirMaker_newValue());
    dir.mkdirs();
    return dir;
  }

  private static long TempDirMaker_newValue() {
    long value;
    do
      value = System.currentTimeMillis();
    while (value == TempDirMaker_lastValue);
    TempDirMaker_lastValue = value;
    return value;
  }

  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 boolean isWindows() {
    return System.getProperty("os.name").contains("Windows");
  }

  public static String makeRandomID(int length) {
    Random random = new Random();
    char[] id = new char[length];
    for (int i = 0; i< id.length; i++)
      id[i] = (char) ((int) 'a' + random.nextInt(26));
    return new String(id);
  }

  static String computerID;
  public static String getComputerID() throws IOException {
    if (noID) return null;
    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);
      }
      if (verbose)
        System.out.println("Local computer ID: " + computerID);
    }
    return computerID;
  }

  static int fileDeletions;

  static void cleanCache() {
    if (verbose)
      System.out.println("Cleaning cache");
    fileDeletions = 0;
    File javax = new File(userHome(), ".javax");
    long now = System.currentTimeMillis();
    File[] files = javax.listFiles();
    if (files != null) for (File dir : files) {
      if (dir.isDirectory() && Pattern.compile("\\d+").matcher(dir.getName()).matches()) {
        long time = Long.parseLong(dir.getName());
        long seconds = (now - time) / 1000;
        long minutes = seconds / 60;
        long hours = minutes / 60;
        if (hours >= 1) {
          //System.out.println("Can delete " + dir.getAbsolutePath() + ", age: " + hours + " h");
          removeDir(dir);
        }
      }
    }
    if (verbose && fileDeletions != 0)
      System.out.println("Cleaned cache. File deletions: " + fileDeletions);
  }

  static void removeDir(File dir) {
    if (dir.getAbsolutePath().indexOf(".javax") < 0)  // security check!
      return;
    for (File f : dir.listFiles()) {
      if (f.isDirectory())
        removeDir(f);
      else {
        if (verbose)
          System.out.println("Deleting " + f.getAbsolutePath());
        f.delete();
        ++fileDeletions;
      }
    }
    dir.delete();
  }

  static void showSystemProperties() {
    System.out.println("System properties:\n");
    for (Map.Entry<Object, Object> entry : System.getProperties().entrySet()) {
      System.out.println("  " + entry.getKey() + " = " + entry.getValue());
    }
    System.out.println();
  }

  static void showVersion() {
    //showSystemProperties();
    boolean eclipseFound = hasEclipseCompiler();
    //String platform = System.getProperty("java.vendor") + " " + System.getProperty("java.runtime.name") + " " + System.getProperty("java.version");
    String platform = System.getProperty("java.vm.name") + " " + System.getProperty("java.version");
    String os = System.getProperty("os.name"), arch = System.getProperty("os.arch");
    System.out.println("This is " + version + ".");
    System.out.println("[Details: " +
      (eclipseFound ? "Eclipse compiler (good)" : "javac (not so good)")
      + ", " + platform + ", " + arch + ", " + os + "]");
  }

  private static boolean hasEclipseCompiler() {
    boolean compilerFound = false;
    try { getEclipseCompiler(); compilerFound = true; } catch (ClassNotFoundException e) {}
    return compilerFound;
  }

  static boolean isAndroid() {
    return System.getProperty("java.vendor").toLowerCase().indexOf("android") >= 0;
  }

  static void set(Class c, String field, Object value) {
    try {
      Field f = set_findStaticField(c, field);
      f.setAccessible(true);
      f.set(null, value);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  static Field set_findStaticField(Class<?> c, String field) {
    for (Field f : c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
  }
} // class _x18 modified for Android

interface Function {
  public Object process(Object in);
  public void toJava_process(Code code);
}

interface ReversibleFunction extends Function {
  public Object unprocess(Object in);
  public void toJava_unprocess(Code code);
}

// generic learner (works on objects)
interface Learner {
  public void processInOut(Object in, Object out);
  public Object processIn(Object in);
  public void toJava(Code code);
  public void tryAgain();
}

abstract class Base {
  void printVars() {
    StringBuilder buf = new StringBuilder();
    Field[] fields = getClass().getDeclaredFields();
    for (Field field : fields) {
      if ((field.getModifiers() & Modifier.STATIC) != 0)
        continue;
      Object value;
      try {
        value = field.get(this);
      } catch (Exception e) {
        value = "?";
      }
      
      if (!(buf.length() == 0)) buf.append(", ");
      buf.append(field.getName() + "=" + value);
    }
    System.out.println(buf.toString());
  }
  
  String name() {
    return getClass().getName().replaceAll("^main\\$", "");
  }
  
  void debug(String s) {
    System.out.println(name() + ": " + s);
  }
}

abstract class LearnerImpl extends Base implements Learner {
  public void tryAgain() {
    throw new RuntimeException("No try again");
  }
  
  public void toJava(Code code) {
    main.todo();
  }
}

abstract class FunctionImpl extends Base implements Function {
  public void toJava_process(Code code) {
    main.todo();
  }
}

class Code {
  StringBuilder buf = new StringBuilder();
  String var = "in";
  String indent = "";
  List<String> translators = new ArrayList<String>();
  List<String> varStack = new ArrayList<String>();
  int varCounter;
  
  Code() {
    translators.add("!636");
  }
  
  void line(String line) {
    buf.append(indent).append(line).append('\n');
  }
  
  void indent() {
    indent += "  ";
  }
  
  void unindent() {
    indent = indent.substring(0, indent.length()-2);
  }
  
  void translators(String... ids) {
    for (String id : ids)
      if (! translators.contains(id)) // space is needed otherwise translator 636 is fooled :)
        translators.add(id);
  }
  
  String getTranslators() {
    // TODO: We should really fix the "standard functions" translator
    // to properly find the main class.
    //
    // As a hack, we move it upwards (before classes adding)
    int i = translators.indexOf("!629");
    if (i >= 0) {
      translators.remove(i);
      translators.add(0, "!629");
    }
    
    return main.fromLines(translators);
  }

  String s() {
    return "((String) " + var + ")";
  }
  
  String list() {
    return "((List) " + var + ")";
  }
  
  void assign(String exp) {
    line(var + " = " + exp + ";");
  }
  
  void newVar() {
    varStack.add(var);
    var = "_v" + (++varCounter);
    line("Object " + var + ";");
  }
  
  void oldVar() {
    var = varStack.get(varStack.size()-1);
    varStack.remove(varStack.size()-1);
  }
}

public class main {
  // The following two fields are filled by JavaX.
  static Object androidContext;
  static String programID;
  
  static final String ALL = "#681";
  
  static boolean classic = false;
  
  static List<Case> cases = new ArrayList<Case>();
  static HashMap<String, Case> casesByID = new HashMap<String, Case>();
  static boolean testJava = false, showFails, execTasks = false;
  static boolean collectClosest = false; // saves time
  static Set<String> parseErrors = new HashSet<String>();
  static int caseIdx;
  static Set<Class> debuggedClasses = new HashSet<Class>();
  static String strategy = "#1000464";
  static String[] innerClasses={
"Case",
"LSplitInput",
"FDropFirstLines",
"LOutSuffix",
"LOutPattern",
"LId",
"LInputPattern",
"LFixed",
"LEach",
"LChange",
"LFindOutInIn",
"LWrap",
"RFJavaTok",
"RFToLines",
"FStringsOnly",
"FNumbersOnly",
"FLength",
"LFixedFunction",
"LTrivial",
"LGetListElement",
"LMath",
"EscapeCase",
"LCharShift",
"LFirst",
"LSwitch",
"LMulti",
"FIsString",
"FCommonPrefix",
"FCommonSuffix",
"Matrix",
"LDistinguishList",
"RunnersUp",
"LBox",
"LBox2",
"LEmptyBox",
"LFixedSubstring",
"LFixWhitespace",
"LCertainElement",
"LOneWordChanged",
"LBla",
"LIntersperse",
"LFixedPositions",
"LMap",
"LPrefixSuffix",
"LRemoveInputSuffix",
"FBeforeColon",
"FAfterColon",
"FUnquote",
"LCombineTwoFunctions",
"LCombineTwoFunctions2",
"Stepper",
};
  static List<Throwable> strategyParseErrors = new ArrayList<Throwable>();
  static Learner trying;
  static String user, pass;
  static boolean edit;

  public static void main(String[] args) throws Exception {
    keepAlive();
    _x18.androidContext = androidContext;
    long startTime = System.currentTimeMillis();
    
    List<String> snippetIDs = new ArrayList<String>();
    List<String> inputs = new ArrayList<String>();
    List<String> inputDocs = new ArrayList<String>();
    List<Case> userCases = new ArrayList<Case>();
    
    for (int i = 0; i < args.length; i++) {
      String arg = args[i];
      if (arg.equals("debug"))
        debugOn(args[++i]);
      else if (arg.equals("user"))
        user = args[++i];
      else if (arg.equals("pass")) {
        pass = args[++i];
        args[i] = "hidden";
      } else if (arg.equals("edit"))
        edit = true;
      else if (arg.equals("in")) {
        String in = args[++i];
        //System.out.println("in=" + quote(in));
        String quoteUnquote = unquote("\"" + in + "\"");
        //System.out.println("now in=" + quote(quoteUnquote));
        inputs.add(quoteUnquote);
      } else if (arg.equals("in-doc"))
        inputDocs.add(args[++i]);
      else if (arg.equals("-notestjava"))
        testJava = false;
      else if (arg.equals("-testjava"))
        testJava = true;
      else if (arg.equals("-withexec"))
        execTasks = true;
      else if (arg.equals("-showfails"))
        showFails = true;
      else if (arg.equals("-classic"))
        classic = true;
      else if (arg.equals("strategy"))
        strategy = args[++i];
      else if (arg.equals("all"))
        snippetIDs.add(ALL);
      else if (isSnippetID(arg))
        snippetIDs.add(arg);
      else
        System.err.println("Unknown argument: " + arg + ", ignoring");
    }
    
    if (snippetIDs.isEmpty()) {
      String s = loadTextFile("input/input.txt", null);
      if (s != null)
        parse(s);
      else
        parse(ALL);
    }
    
    for (String snippetID : snippetIDs)
      try {
        Case _case = parse(snippetID);
        if (_case != null) {
          _case.halfExamples.addAll(inputs);
          for (String docID : inputDocs)
            _case.halfExamples.add(loadSnippet(docID));
          userCases.add(_case);
        }
      } catch (Throwable e) {
        e.printStackTrace();
        parseErrors.add(snippetID);
      }
    
    int solved = 0, n = cases.size(), goodJava = 0;
    for (caseIdx = 0; caseIdx < n; caseIdx++) {
      Case _case = cases.get(caseIdx);
      try {
        calculate(_case);
      } catch (Throwable e) {
        e.printStackTrace();
      }
      if (_case.winner != null)
        ++solved;
      if (_case.goodJava)
        ++goodJava;
      if (caseIdx+1 == solved)
        System.out.println((caseIdx+1) + " case(s) processed & solved.");
      else
        System.out.println((caseIdx+1) + " case(s) processed, " + solved + " solved.");
      if (testJava && goodJava < solved)
        System.out.println((solved-goodJava) + " case(s) with BAD JAVA.");
    }

    System.out.println("");    
    System.out.println("----");

    List<Case> sorted = casesSortedByID();
    boolean allSolved = solved == n;
    if (solved != 0) {
      System.out.println();
      System.out.print("Solved: ");
      for (Case _case : sorted)
        if (_case.winner != null)
          System.out.print(_case.id + " ");
      System.out.println();
    }
    if (testJava && solved > goodJava) {
      System.out.println();
      System.out.print("Bad Java: ");
      for (Case _case : sorted)
        if (_case.winner != null && !_case.goodJava)
          System.out.print(_case.id + " ");
      System.out.println();
    }
    if (!allSolved) {
      System.out.println();
      System.out.print("Unsolved: ");
      for (Case _case : sorted)
        if (_case.winner == null)
          System.out.print(_case.id + " ");
      System.out.println();
    }
    if (!parseErrors.isEmpty()) {
      System.out.print("\nParse errors: ");
      for (String id : parseErrors)
          System.out.print(id + " ");
      System.out.println();
    }
    if (!strategyParseErrors.isEmpty())
      System.out.println("Strategy parse errors!");
    System.out.println();
    if (allSolved && testJava && goodJava < solved)
      System.out.println("ALL SOLVED (" + solved + "), but some BAD JAVA.");
    else {
      System.out.println(allSolved ? "ALL SOLVED (" + solved + ")" : "Solved " + solved + " out of " + n + ".");
      if (testJava)
        if (goodJava == solved)
          System.out.println("All Java code OK" + (allSolved ? "" : " (for solved cases)") + ".");
        else
          System.out.println("Some bad Java.");
      else
        System.out.println("Java not tested.");
    }
    System.out.println("");

    if (edit) {
      if (userCases.size() != 1) fail("Edit: More than one user case, confused");
      Case _case = userCases.get(0);
      for (String docID : inputDocs) {
        Object _out = _case.processIn(loadSnippet(docID));
        if (!(_out instanceof String))
          fail("Case did not generate a string: " + structure(_out));
        String out = (String) ( _out);
        String editInfo = "Solver #" + programID + " " + join(" ", args);
        editSnippetText(docID, out, editInfo);
      }
    }

    /*long time = getUserTime();
    if (time >= 0)
      System.out.println("User time: " + formatDouble(time/1e9, 3) + "s");*/
      
    long time = System.currentTimeMillis()-startTime;
    System.out.println("Real time: " + formatDouble(time/1e3, 3) + "s");
  }
  
  public static String formatDouble(double d, int digits) {
    String format = "0.";
    for (int i = 0; i < digits; i++) format += "#";
    String s = new DecimalFormat(format).format(d);
    return s.replace(',', '.'); // hack german -> english
  }
  
  /** Get user time in nanoseconds. */
  public static long getUserTime( ) {
    ThreadMXBean bean = ManagementFactory.getThreadMXBean();
    return bean.isCurrentThreadCpuTimeSupported() ?
      bean.getCurrentThreadUserTime() : -1L;
  }
  
  static class Case {
    String id;
    List<Object[]> fullExamples = new ArrayList<Object[]>();
    List<Object> halfExamples = new ArrayList<Object>();
    List<Object[]> examples1, examples2;
    Learner winner;
    RunnersUp runnersUp = collectClosest ? new RunnersUp() : null;
    boolean goodJava;
    List<Case> combined;
    int splitPoint = -1;
    
    // stats
    int learnersTried, retries;

    void split() {    
      if (examples1 != null)
        return; // already done
      if (fullExamples.size() < 2)
        throw new RuntimeException("Too few examples (" + fullExamples.size() + ")");
      if (splitPoint < 0)
        splitPoint = fullExamples.size()-1;
      System.out.println("Full examples: " + fullExamples.size() + ", splitPoint: " + splitPoint + ", half examples: " + halfExamples.size());
      examples1 = fullExamples.subList(0, splitPoint);
      examples2 = fullExamples.subList(splitPoint, fullExamples.size());
    }
    
    void add(Case _case) {
      combined.add(_case);
      fullExamples.addAll(_case.fullExamples);
      halfExamples.addAll(_case.halfExamples);
    }
    
    Object processIn(Object in) {
      return winner.processIn(in);
    }
  }

  static Case parse(String arg) throws Exception {
   try {
    if (arg == null) return null;
    arg = arg.trim();
    if (arg.length() == 0) return null;
    Case _case = new Case();
    String text;
    
    if (casesByID.containsKey(arg))
      return casesByID.get(arg);
      
    if (arg.startsWith("Combine")) {
      _case.id = "Combine";
      _case.combined = new ArrayList<Case>();
      List<String> tok = JavaTok.split(arg);
      List<String> ids = new ArrayList<String>();
      for (int i = 5; i < tok.size(); i += 6) { // skip # and "and"
        Case case2 = parse("#" + tok.get(i));
        _case.id += " #" + tok.get(i);
        cases.remove(case2);
        _case.add(case2);
      }
      addCase(_case);
      return _case;
    }
    
    if (isSnippetID(arg)) {
      _case.id = arg;
      text = loadSnippet(arg);
    } else {
      _case.id = "direct (" + shorten(arg, 10) + ")";
      text = arg;
    }

    // it's a collection of cases!
    if (text.trim().startsWith("#") || text.trim().startsWith("Combine")) {
      for (String line : toLines(text))
        parse(line);
      return null;
    }
    
    // it's a "Continue:" task - transform to I/O format
    if (text.trim().startsWith("Continue:")) {
      List<String> lines = toLines(text);
      StringBuilder buf = new StringBuilder();
      for (int i = 1; i < lines.size(); i++) {
        buf.append("In: " + quote("" + i) + "\n");
        buf.append("Out: " + quote(lines.get(i)) + "\n");
      }
      int numAsking = 3;
      for (int i = lines.size(); i < lines.size()+numAsking; i++)
        buf.append("In: " + quote("" + i) + "\n");
      text = buf.toString();
    }
      
    // it's an "Execute." task - run Java(X) and transform to I/O format
    if (text.trim().startsWith("Execute.")) {
      if (!execTasks) return null;
      List<String> tok = JavaTok.split(text);
      StringBuilder buf = new StringBuilder();
      for (int i = 5; i < tok.size(); i += 2) {
        if (tok.get(i).equals("-") && tok.get(i+2).equals("-")) {
          i += 2;
          buf.append("--\n");
        } else {
          String code = unquote_fixSpaces(tok.get(i));
          String result = execute("!636\n" + code);
          buf.append("In: " + quote(code) + "\n");
          buf.append("Out: " + quote(result) + "\n");
        }
      }
      text = buf.toString();
    }

    if (text.trim().startsWith("Marking.")) {
      
      List<String> tok = JavaTok.split(text);
      StringBuilder buf = new StringBuilder();
      for (int i = 5; i < tok.size(); i += 2) {
        if (tok.get(i).equals("-") && tok.get(i+2).equals("-")) {
          i += 2;
          buf.append("--\n");
        } else {
          String out = unquote_fixSpaces(tok.get(i));
          String in = out.replace("[[", "").replace("]]", "");
          buf.append("In: " + quote(in) + "\n");
          buf.append("Out: " + quote(out) + "\n");
        }
      }
      text = buf.toString();
    }
 
    System.out.println(text);
    String in = null, out = null;
    
    List<String> tok = JavaTok.split(text);
    for (int i = 1; i < tok.size(); i += 2) {
      String t = tok.get(i), t2 = i+2 < tok.size() ? tok.get(i+2) : "";
      if (t.equals("-") && t2.equals("-")) {
        i += 2;
        _case.splitPoint = _case.fullExamples.size();
        //System.out.println("t=" + t + ", t2= " + t2);
      } else if (t.toUpperCase().startsWith("I") && t2.equals("-") && tok.get(i+4).toUpperCase().equals("DOC") && tok.get(i+6).equals(":")) { // "In-Doc:"
        if (in != null)
          _case.halfExamples.add(in);
        i += 8;
        int j = findNextLine(tok, i);
        String inID = unquote_fixSpaces(JavaTok.join(tok.subList(i, j-1)));
        in = loadSnippet(inID);
        i = j-2;
        out = null;
      } else if (t.toUpperCase().startsWith("I") && t2.equals(":")) { // "In:" or "I:"
        if (in != null)
          _case.halfExamples.add(in);
        i += 4;
        int j = findNextLine(tok, i);
        in = unquote_fixSpaces(JavaTok.join(tok.subList(i, j-1)));
        i = j-2;
        out = null;
      } else if (t.toUpperCase().startsWith("O") && t2.equals(":")) { // "Out: " or "O: "
        i += 4;
        int j = findNextLine(tok, i);
        out = unquote_fixSpaces(JavaTok.join(tok.subList(i, j-1)));
        i = j-2;
        if ((in + out).indexOf('\t') >= 0)
          System.err.println("WARNING: Tab character used!");
        System.out.println(quote(in) + " => " + quote(out));
        _case.fullExamples.add(new String[] {in, out});
        in = out = null;
      } else {
        int j = findNextLine(tok, i);
        String line = JavaTok.join(tok.subList(i, j-1));
        i = j-2;
        System.out.println("-- Ignoring line: " + line);
      }
    }
    
    if (in != null)
      _case.halfExamples.add(in);
    addCase(_case);
    return _case;
   } catch (Throwable e) {
    parseErrors.add(arg);
    e.printStackTrace();
    return null;
   }
  }
  
  static String unquote_fixSpaces(String s) {
    String _ = unquote(s);
    if (s.startsWith("[["))
      _ = fixSpaces(_);
    return _;
  }
  
  // remove invisible spaces at end of line - this will otherwise confuse the engine(s) greatly...
  static String fixSpaces(String s) {
    System.out.println(quote(s));
    s = s.replaceAll("[\t ]+(\r?\n)", "$1");
    s = s.replaceAll("[\t ]+$", "");
    //System.out.println("_fixSpaces => " + quote(s));
    return s;
  }
  
  // i is a code-token (odd index)
  // return value is also a code token, or end of list
  static int findNextLine(List<String> tok, int i) {
    while (i < tok.size() && tok.get(i-1).indexOf('\n') < 0)
      i += 2;
    return i;
  }
  
  static void addCase(Case _case) {
    cases.add(_case);
    casesByID.put(_case.id, _case);
  }
  
  static void calculate(Case _case) throws Exception {
    System.out.println("\n== CASE " + _case.id + " ==");
    
    _case.split();
    Learner learner = findOKLearner(_case);
    if (learner == null) {
      String stat = "";
      if (_case.retries != 0) stat = " + " + _case.retries + " retries";
      System.out.println("\nProblem not solved (" + _case.learnersTried + " learners tried" + stat + ")");
      RunnersUp ru = _case.runnersUp;
      if (ru != null && ru.winner != null)
        System.out.println("Closest result: " + quote(ru.bestResult) + " instead of " + quote(ru.expected) + " (score " + ru.bestScore + ") by " + structure(ru.winner));
    } else {
      System.out.println("\nSolved!");
      print("  " + structure(learner) + "\n");
      _case.winner = learner;
      Code code = new Code();
      if (testJava) try {
        learner.toJava(code);

        if (testJava)
          testJava(_case, code); // prints "GOOD JAVA" or "BAD JAVA"
        else
          System.out.println("Java:");
          
        System.out.println(indent("  ", code.getTranslators()));
        System.out.println(indent("  ", code.buf.toString()));
      } catch (Throwable e) {
        System.out.println("BAD JAVA");
      }
        
      for (Object in : _case.halfExamples) {
        Object out = learner.processIn(in);
        System.out.println(structure(in) + " =>! " + structure(out));
      }
    }
  }

  static void choice_orderList(List l) {
  }
  
  static Learner findOKLearner(Case _case) throws Exception {
    List<Learner> list = makeLearners();
    choice_orderList(list);
    for (Learner learner : list) try {
      if (learnerOK(learner, _case))
        return learner;
    } catch (Throwable e) {
      if (showFails)
        e.printStackTrace();
    }
    
    if (_case.combined != null) {
      Case switchCase = makeSwitchCase(_case);
      calculate(switchCase);
      Learner learner = switchCase.winner;
      if (learner != null)
        return new LSwitch(_case, learner);
    }
    
    return null;
  }
  
  static Case makeSwitchCase(Case _case) {
    int i = 0;
    Case s = new Case();
    s.id = "Switch " + _case.id;
    s.examples1 = new ArrayList<Object[]>();
    s.examples2 = new ArrayList<Object[]>();
    for (Case c : _case.combined) {
      ++i;
      for (Object[] e : c.examples1)
        s.examples1.add(new Object[] {e[0], String.valueOf(i)});
      for (Object[] e : c.examples2)
        s.examples2.add(new Object[] {e[0], String.valueOf(i)});
      for (Object[] e : c.fullExamples)
        s.fullExamples.add(new Object[] {e[0], String.valueOf(i)});
    }
    return s;
  }
  
  static boolean learnerOK(Learner learner, Case _case) {
    trying = learner;
    
    try {
      Object[] _e = null;
      try {
        if (_case.examples1 == null)
          fail("Case not calculated: " + _case.id);
          
        ++_case.learnersTried;
        for (Object[] e : _case.examples1) {
          _e = e;
          learner.processInOut(e[0], e[1]);
        }
        
        // full validation against all examples - but starting with the unknown ones to make coding easier for learners
        int retry = 0;
        retryLoop: while (true) {
          int n = _case.fullExamples.size();
          for (int i = 0; i < n; i++) {
            Object[] e = _case.fullExamples.get((i+_case.examples1.size()) % n);
            _e = e;
            Object out = learner.processIn(e[0]);
            if (!e[1].equals(out)) {
            
              if (_case.runnersUp != null && e[1] instanceof String && out instanceof String)
                _case.runnersUp.add((String) e[1], (String) out, leven((String) out, (String) e[1]), learner);
                
              if (debuggedClasses.contains(learner.getClass()) || showFails)
                System.out.println("[fail] " + structure(learner) + " on " + structure(e[0]) + " - got: " + structure(out) + " rather than: " + structure(e[1]));
              ++retry;
              ++_case.retries;
              if (retry % 1000 == 0)
                System.err.println("Retry " + retry);
              learner.tryAgain();
              continue retryLoop;
            }
          }
          return true;  // all test examples passed
        }
      } catch (Throwable e) {
        if (debuggedClasses.contains(learner.getClass()) || showFails) {
          e.printStackTrace();
          System.err.println("[fail] " + structure(learner) + " on " + (_e == null ? "?" : structure(_e[0])) + " - " + e);
        }
        return false;
      }
    } finally {
      trying = null;
    }
  }
  
  static boolean validate(String[] example, Learner learner) {
    try {
      String out = (String) learner.processIn(example[0]);
      if (!example[1].equals(out)) {
          //System.out.println("[fail] " + learner + " on " + quote(e[0]) + " - got: " + quote(out) + " rather than: " + quote(e[1]));
          return false;
        }
      return true;
    } catch (Throwable e) {
      silentException(e);
      return false;
    }
  }
  
  static void silentException(Throwable e) {
  }
  
  static List<Learner> makeLearners() { try {
 
    String s = isSnippetID(strategy) ? loadSnippet(strategy) : strategy;
    s += "\n" + combineClasses();
    System.out.println("Strategy:\n" + s);
    List<Learner> list = parseStrategy(s);
    if (classic)
      list.addAll(classicLearners()); // Endlosschleife!?
    return list;
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  
  static String combineClasses() {
    StringBuilder buf = new StringBuilder();
    for (String s : innerClasses) {
      Class c = findClass(s);
      if (c == null) System.err.println("Warning: Class not found - " + s);
      else if (isSubclass(c, Learner.class)) {
        if (hasConstructor(c))
          buf.append(getName(c) + "\n");
        else
          for (String s2 : innerClasses) {
            Class c2 = findClass(s2);
            if (c2 != null && hasConstructor(c, c2))
              buf.append(getName(c) + " " + getName(c2) + "\n");
          }
      }
    }
    return buf.toString();
  }
  
  static List<Learner> parseStrategy(String strategyText) { try {
 
    List <String> lines = toLines(strategyText);
    List<Learner> list = new ArrayList<Learner>();
    for (String s : lines) try {
      s = s.trim();
      String[] parts = s.split(" +");
      if (parts.length == 0) continue;
      
      Stack<Object> stack = new Stack<Object>();
      for (int i = parts.length-1; i >= 0; i--) {
        String p = parts[i];
        Class c = findClassFlex(p);
        if (c == null)
          fail("Strategy element " + p + " not known");
        
        Constructor ctr = c.getDeclaredConstructors()[0];
        Class[] types = ctr.getParameterTypes();
        if (types.length == 0)
          stack.add(ctr.newInstance());
        else if (types.length == 1) {
          if (stack.isEmpty())
            fail("Too few arguments for " + c.getName());
          stack.add(ctr.newInstance(stack.pop()));
        } else if (types.length == 2) {
          if (stack.size() < 2)
            fail("Too few arguments for " + c.getName());
          Object a = stack.pop();
          Object b = stack.pop();
          stack.add(ctr.newInstance(a, b));
        } else
          fail("bla");
        
        /*if (isSubclass(c, ReversibleFunction.class)) {
          l = new LWrap((ReversibleFunction) newInstance(c), l);
          continue;
        }*/
      }
      
      list.add((Learner) stack.peek());
    } catch (Throwable e) {
      System.err.println("Strategy parse error.");
      e.printStackTrace();
      strategyParseErrors.add(e);
    }
    return list;
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}

  static List<Learner> classicLearners() {
    List<Learner> list = new ArrayList<Learner>();
    list.addAll(level1());
    list.add(new LBox(new LMulti(level1())));
    list.add(new LBox2(new LMulti(level1())));
    
    list.add(new LChange(new FCommonPrefix(), new LOutPattern()));
    list.add(new LChange(new FCommonSuffix(), new LOutPattern()));
    
    list.add(new LEmptyBox(new LMulti(level1())));
    
    list.add(new LChange(new RFToLines(), new LFixedFunction(new FLength())));
    
    // for #1000455
    list.add(new LFindOutInIn(new LFixedSubstring()));
   
    for (int I = 1; I <= 2; I++)
    // for #1000457
    list.add(new LChange(new FDropFirstLines(I), new LMulti(
      new LFixWhitespace(l1()), level1())));

    // for #1000458
    list.add(new LFixWhitespace(l1()));

    return list;
  }

  static Learner l1() {
    return new LMulti(level1());
  }
  
  static List<Learner> level1() {
    List<Learner> list = new ArrayList<Learner>();
    list.add(new LId()); // always good to have as included learner
    list.add(new LPrefixSuffix());
    list.add(new LSplitInput(new LOutPattern()));
    list.add(new LInputPattern());
    list.add(new LFixed());
    list.add(new LWrap(new RFJavaTok(), new LEach(new LFixedFunction(new EscapeCase()))));
    list.add(new LCharShift());
    list.add(new LOutSuffix(new LFirst(new LCharShift())));
    
    list.add(new LChange(new RFJavaTok(), new LMulti(
      new LChange(new FStringsOnly(), new LGetListElement()),
      new LChange(new FNumbersOnly(), new LMath()))
    ));
    
    // TODO - for #1000378
    list.add(new LChange(new RFJavaTok(), new LDistinguishList(new FIsString())));
    
    list.add(new LFixedSubstring());
    
    // of no use now it seems
    // list.add(new LTryPrevious());
    
    return list;
  }
  
  // enhanced with robust multilines
  public static String unquote(String s) {
    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)
      //return s.substring(1, s.length()-1).replace("\\\"", "\"").replace("\\\\", "\\");
      return unescapeJavaString(s.substring(1, s.length()-1));
    else
      return s; // return original
  }
  
  /** from: http://stackoverflow.com/questions/3537706/howto-unescape-a-java-string-literal-in-java,
      or: https://gist.github.com/uklimaschewski/6741769
      
      Thanks!
  */
  public static String unescapeJavaString(String st) {
    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;
            }
            i++;
        }
        sb.append(ch);
    }
    return sb.toString();
  }
  
  static String indent(String indent, String s) {
    return indent + s.replace("\n", "\n" + indent);
  }
  
  static void debugOn(String name) {
    try {
      Class c = findClassFlex(name);
      debuggedClasses.add(c);
      Field field;
      while (true)
        try {
          field = c.getDeclaredField("debug");
          break;
        } catch  (NoSuchFieldException e) {
          c = c.getSuperclass();
        }
      field.setBoolean(null, true);
    } catch (Exception e) {
      e.printStackTrace();
      System.err.println("Cannot debug class " + name);
    }
  }

static int choice(String text, int i) {
  return i;
}
  
  // splits the input at some point, takes only one part
  static class LSplitInput extends LearnerImpl {
    int splitIdx = 1; // split after first character
    Learner baseLearner;
    
    LSplitInput(Learner baseLearner) {
      this.baseLearner = baseLearner;
      splitIdx = choice("LSplitInput.i", splitIdx);
    }
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      in = in.substring(splitIdx);
      baseLearner.processInOut(in, out);
    }
    
    public Object processIn(Object _in) {
      String in = (String) _in;
      in = in.substring(splitIdx);
      return baseLearner.processIn(in);
    }
    
    public void toJava(Code code) {
      if (splitIdx != 0)
        code.line(code.var + " = ((String) " + code.var + ").substring(" + splitIdx + ");");
      baseLearner.toJava(code);
    }
  }

  static class FDropFirstLines implements Function {
    int n;
    FDropFirstLines(int n) {
  this.n = n;}

    public Object process(Object _in) {
      String in = (String)_in;
      for (int I=0; I < n; I++)
        in = in.substring(in.indexOf('\n')+1);
      return in;
    }
    
    public void toJava_process(Code code) {
      todo();
    }
  }
  
  // removes common suffix from out, delegates to base learner
  static class LOutSuffix extends LearnerImpl {
    String suffixOut = "";
    Learner baseLearner;
    
    LOutSuffix(Learner baseLearner) {
      this.baseLearner = baseLearner;
    }
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      if (out.endsWith("!"))
        suffixOut = "!";
      if (out.endsWith(suffixOut))
        out = out.substring(0, out.length()-suffixOut.length());
      
      baseLearner.processInOut(in, out);
    }
    
    public Object processIn(Object _in) {
      String in = (String) _in;
      return baseLearner.processIn(in) + suffixOut;
    }
    
    public void toJava(Code code) {
      baseLearner.toJava(code);
      if (suffixOut.length() != 0)
        code.line(code.var + " = " + code.s() + "+" + quote(suffixOut) + ";");
    }
  }
  
  // if input appears in output in fixed pattern
  static class LOutPattern extends LearnerImpl {
    static boolean debug;
    String pattern = "%!%";

    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      pattern = out.replace(in, "%!%");
      if (debug)
        System.out.println("LOutPattern: in=" + quote(in) + ", out=" + quote(out) + ", pattern=" + quote(pattern));
    }
    
    public String processIn(Object _in) {
      String in = (String) _in;
      return pattern.replace("%!%", in);
    }
    
    public void toJava(Code code) {
      code.line(code.var + " = " + quote(pattern) + ".replace(" + quote("%!%") + ", (String) " + code.var + ");");
    }
  }
  
  // simplets learner - only knows the "id" function
  static class LId extends LearnerImpl {
    public void processInOut(Object in, Object out) {
    }
    
    public Object processIn(Object in) {
      return in;
    }
    
    public void toJava(Code code) {
    }
  }
  
  // for "find" tasks (e.g. "abcde" to "[[abc]]de")
  static class LInputPattern extends LearnerImpl {
    String regexp = "", findMarker1 = "[[", findMarker2 = "]]";
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      int i = out.indexOf(findMarker1), j = out.indexOf(findMarker2, i+1);
      if (j < 0) return;
      String s = out.substring(i+2, j);
      regexp = s.replaceAll("\\d+", Matcher.quoteReplacement("\\d+"));
      System.out.println("regexp: " + regexp);
    }
    
    public String processIn(Object _in) {
      String in = (String) _in;
      if (regexp.length() == 0)
        return in;
      else
        return in.replaceAll("(" + regexp + ")", findMarker1 + "$1" + findMarker2);
    }
    
    public void toJava(Code code) {
      code.line(code.var + " = ((String) " + code.var + ").replaceAll(" + quote("(" + regexp + ")") + ", \"[[$1]]\");");
    }
  }
  
  static class LFixed extends LearnerImpl {
    static boolean debug;
    Object value;
    
    public void processInOut(Object in, Object out) {
      value = out;
      if (debug)
        printVars();
    }
    
    public Object processIn(Object in) {
      return value;
    }
    
    public void toJava(Code code) {
      code.line(code.var + " = " + quote((String) value) + ";");
    }
  }
  
  static void fail() {
    throw new RuntimeException("fail");
  }
  
  static void fail(String msg) {
    throw new RuntimeException(msg);
  }
  
  static void assertSameSize(List a, List b) {
    if (a.size() != b.size())
      fail("wrong list sizes");
  }

  // process lists in parallel
  // (in and out must be a list of same length)
  static class LEach extends LearnerImpl {
    static boolean debug;
    Learner base;
    
    LEach(Learner base) {
      this.base = base;
    }
    
    public void processInOut(Object _in, Object _out) {
      List in = (List) _in, out = (List) _out;
      assertSameSize(in, out);
      for (int i = 0; i < in.size(); i++)
        base.processInOut(in.get(i), out.get(i));
      if (debug)
        printVars();
    }
    
    public Object processIn(Object _in) {
      List in = (List) _in;
      List out = new ArrayList();
      for (Object x : in)
        out.add(base.processIn(x));
      return out;
    }
    
    public void toJava(Code code) {
      code.line("List out = new ArrayList();");
      code.line("for (Object x : (List) in) {");
      code.indent();
      code.line("in = x;");
      base.toJava(code);
      code.line("out.add(in);");
      code.unindent();
      code.line("}");
      code.line("in = out;");
    }
  }
  
  static class LChange extends LearnerImpl {
    Function f;
    Learner base;
    
    LChange(Function f, Learner base) {
      this.f = f;
      this.base = base;
    }
    
    public void processInOut(Object in, Object out) {
      in = f.process(in);
      base.processInOut(in, out);
    }
    
    public Object processIn(Object in) {
      in = f.process(in);
      return base.processIn(in);
    }
    
    public void toJava(Code code) {
      f.toJava_process(code);
      base.toJava(code);
    }
  }
  
  static class LFindOutInIn extends LearnerImpl {
    static boolean debug;
    Learner base;
    String findMarker1 = "{{", findMarker2 = "}}";
    
    LFindOutInIn(Learner base) {
  this.base = base;}
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      if (out.length() == 0)
        out = in;
      else {
        int i = in.indexOf(out);
        if (i < 0) throw new RuntimeException("error");
        int j = i+out.length();
        out = in.substring(0, i) + findMarker1 + in.substring(i, j) + findMarker2 + in.substring(j);
        if (debug)
          System.out.println("LFindOutInIn: index=" + i);
      }
      
      base.processInOut(in, out);
      
      if (debug)
        System.out.println("LFindOutInIn: Base learned. " + base);
    }
    
    public Object processIn(Object _in) {
      if (debug)
        System.out.println("LFindOutInIn: processIn");
      String in = (String) _in;
      String out = (String) base.processIn(in);
      int i = out.indexOf(findMarker1), j = out.indexOf(findMarker2, i)-2;
      String result = i < 0 ? "" : in.substring(i, j);
      if (debug)
        System.out.println("LFindOutInIn: processIn " + i + " " + j + " " + quote(result));
      return result;
    }
    
    public void tryAgain() {
      base.tryAgain();
    }
  }
  
  static class LWrap extends LearnerImpl {
    ReversibleFunction f;
    Learner base;
    
    LWrap(ReversibleFunction f, Learner base) {
  this.base = base;
  this.f = f;}
    
    public void processInOut(Object in, Object out) {
      in = f.process(in);
      out = f.process(out);
      base.processInOut(in, out);
    }
    
    public Object processIn(Object in) {
      in = f.process(in);
      in = base.processIn(in);
      in = f.unprocess(in);
      return in;
    }
    
    public void toJava(Code code) {
      f.toJava_process(code);
      base.toJava(code);
      f.toJava_unprocess(code);
    }
  }
  
  static class RFJavaTok implements ReversibleFunction {
    public Object process(Object in) {
      return JavaTok.split((String) in);
    }
    
    public Object unprocess(Object in) {
      return JavaTok.join((List) in);
    }
    
    public void toJava_process(Code code) {
      code.translators("!636", "!686");
      code.line(code.var + " = JavaTok.split((String) " + code.var + ");");
    }
    
    public void toJava_unprocess(Code code) {
      code.translators("!636", "!686");
      code.line(code.var + " = JavaTok.join((List) " + code.var + ");");
    }
  }
  
  static class RFToLines implements ReversibleFunction {
    public Object process(Object in) {
      return toLines((String) in);
    }
    
    public Object unprocess(Object in) {
      return fromLines((List) in);
    }
    
    public void toJava_process(Code code) {
      code.translators("!636", "!629");
      code.assign("toLines(" + code.s() + ");");
    }
    
    public void toJava_unprocess(Code code) {
      code.translators("!636", "!629");
      code.assign("fromLines(" + code.list() + ");");
    }
  }
  
  // works on a token list - makes a list of only the string constants (unquoted)
  static class FStringsOnly implements Function {
    static boolean debug;
    
    public Object process(Object _in) {
      List<String> tok = new ArrayList<String>();
      for (String s : (List<String>) _in) {
        boolean isString = s.startsWith("\"") || s.startsWith("[[");
        if (isString)
          tok.add(unquote(s));
        if (debug)
          System.out.println("FStringsOnly - isString: " + isString + " - " + s);
      }
      return tok;
    }
    
    public void toJava_process(Code code) {
      code.translators("!629");
      code.line("List<String> tok = new ArrayList<String>();");
      code.line("for (String s : (List<String>) " + code.var + ")");
      code.line("  if (s.startsWith(\"\\\"\") || s.startsWith(\"[[\")) tok.add(unquote(s));");
      code.assign("tok");
    }
  }
  
  // works on a token list - makes a list of only the number constants
  static class FNumbersOnly implements Function {
    static boolean debug;
    
    public Object process(Object _in) {
      List<String> tok = new ArrayList<String>();
      for (String s : (List<String>) _in) {
        boolean isNumber = s.length() != 0 && (Character.isDigit(s.charAt(0)) || (s.charAt(0) == '-' && s.length() > 1));
        if (isNumber)
          tok.add(s);
        if (debug)
          System.out.println("FNumbersOnly - isNumber: " + isNumber + " - " + s);
      }
      return tok;
    }
    
    public void toJava_process(Code code) {
      code.line("List<String> tok = new ArrayList<String>();");
      code.line("for (String s : (List<String>) " + code.var + ")");
      code.line("  if (s.length() != 0 && (Character.isDigit(s.charAt(0)) || (s.charAt(0) == '-' && s.length() > 1))) tok.add(s);");
      code.assign("tok");
    }
  }
  
  static class FLength implements Function {
    static boolean debug;
    
    public Object process(Object in) {
      Object result = String.valueOf(in instanceof List ? ((List) in).size() : ((String) in).length());
      if (debug)
        System.out.println("FLength: " + result);
      return result;
    }
    
    public void toJava_process(Code code) {
      code.assign("String.valueOf(" + code.var + " instanceof List ? " + code.list() + ".size() : " + code.s() + ".length())");
    }
  }
  
  static class LFixedFunction extends LearnerImpl {
    Function f;
    
    LFixedFunction(Function f) {
      this.f = f;
    }
    
    public void processInOut(Object in, Object out) {
    }
    
    public Object processIn(Object in) {
      return f.process(in);
    }
    
    public void toJava(Code code) {
      f.toJava_process(code);
    }
  }
  
  // trivial stuff like taking the one element out of a 1-element list
  static class LTrivial extends LearnerImpl {
    public void processInOut(Object in, Object out) {
    }
    
    public Object processIn(Object in) {
      return ((List) in).get(0);
    }
    
    public void toJava(Code code) {
      code.assign(code.list() + ".get(0)");
    }
  }
  
  // get element of a list at fixed index
  static class LGetListElement extends LearnerImpl {
    static boolean debug;
    int i;
    
    public void processInOut(Object _in, Object out) {
      List in = (List) _in;
      i = in.indexOf(out);
      if (debug)
        System.out.println("LGetListElement: " + i + " " + out);
    }
    
    public Object processIn(Object in) {
      return ((List) in).get(i);
    }
    
    public void toJava(Code code) {
      code.assign(code.list() + ".get(" + i + ")");
    }
  }
  
  // math operations
  static class LMath extends LearnerImpl {
    static boolean debug;
    String allOperations = "+ - * /";
    Set<String> possibleOperations = new TreeSet<String>();
    
    LMath() {
      possibleOperations.addAll(Arrays.asList(allOperations.split(" +")));
    }
    
    public void processInOut(Object _in, Object _out) {
      List in = (List) _in;
      String out = (String) _out;
      BigInteger[] inNumbers = getNumbers(in);
      BigInteger[] outNumbers = new BigInteger[] {getNumber(out)};
      findOperation(inNumbers, outNumbers);
      if (debug)
        System.out.println("Operations: " + possibleOperations);
    }
    
    public void findOperation(BigInteger[] in, BigInteger[] out) {
      filterOperations(in, out);
      if (possibleOperations.isEmpty())
        fail("tilt");
    }
      
    public void filterOperations(BigInteger[] in, BigInteger[] out) {
      for (Iterator<String> i = possibleOperations.iterator(); i.hasNext(); ) {
        String op = i.next();
        BigInteger[] out2 = doOperation(op, in);
        if (out2 == null || !arraysEqual(out, out2))
          i.remove(); // keep only matching operations
      }
    }
    
    public BigInteger[] doOperation(String op, BigInteger[] in) {
      op = op.intern();
      try {
        if (in.length == 2) {
          BigInteger a = in[0], b = in[1], x = null;
          if (op == "+")
            x = a.add(b);
          else if (op == "-")
            x = a.subtract(b);
          else if (op == "*")
            x = a.multiply(b);
          else if (op == "/")
            x = a.divide(b);
          return x != null ? new BigInteger[] {x} : null;
        }
        return null;
      } catch (Throwable e) {
        return null;
      }
    }
    
    public String processIn(Object _in) {
      List<String> in = (List<String>) _in;
      String op = possibleOperations.iterator().next();
      if (debug)
        System.out.println("op: " + op);
      BigInteger[] inNumbers = getNumbers(in);
      BigInteger[] outNumbers = doOperation(op, inNumbers);
      return outNumbers[0].toString();
    }
    
    String BI = BigInteger.class.getName();
    
    public void toJava(Code code) {
      String op = possibleOperations.iterator().next();
      String a = "new " + BI + "((String) " + code.list() + ".get(0))";
      String b = "new " + BI + "((String) " + code.list() + ".get(1))";
      if (op.equals("+"))
        code.assign(a + ".add(" + b + ").toString()");
      else
        todo();
    }
    
    static BigInteger[] getNumbers(List<String> in) {
      BigInteger[] big = new BigInteger[in.size()];
      for (int i = 0; i < in.size(); i++)
        big[i] = new BigInteger(in.get(i));
      return big;
    }
    
    static BigInteger getNumber(String s) {
      return new BigInteger(s);
    }
    
    static boolean arraysEqual(BigInteger[] a, BigInteger[] b) {
      if (a.length != b.length) return false;
      for (int i = 0; i < a.length; i++)
        if (!a[i].equals(b[i])) return false;
      return true;
    }
  }
  
  static class EscapeCase implements Function {
    static boolean debug;
    
    public Object process(Object _in) {
      if (debug)
        System.out.println("EscapeCase: " + _in);
      String in = (String) _in;
      return in.equals("case") ? "_case" : in;
    }
    
    public void toJava_process(Code code) {
      code.line("if (\"case\".equals(" + code.var + ")) " + code.var + " = " + quote("_case") + ";");
    }
  }
  
  static class LCharShift extends LearnerImpl {
    int shift;
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      shift = (int) out.charAt(0) - (int) in.charAt(0);
    }
    
    public Object processIn(Object _in) {
      String in = (String) _in;
      char[] c = new char[in.length()];
      for (int i = 0; i < c.length; i++)
        c[i] = (char) ((int) in.charAt(i) + shift);
      return new String(c);
    }
    
    public void toJava(Code code) {
      code.line("char[] c = new char[((String) " + code.var + ").length()];");
      code.line("for (int i = 0; i < c.length; i++)");
      code.line("  c[i] = (char) ((int) ((String) " + code.var + ").charAt(i)" + (shift < 0 ? "" + shift : "+" + shift) + ");");
      code.line(code.var + " = new String(c);");
    }
  }
  
  // applies base learner to first char of string
  // (or first element of list, TODO)
  static class LFirst extends LearnerImpl {
    Learner baseLearner;
    
    LFirst(Learner baseLearner) {
      this.baseLearner = baseLearner;
    }
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      if (in.length() == 0)
        return;
      String firstIn = in.substring(0, 1), firstOut = out.substring(0, 1);
      baseLearner.processInOut(firstIn, firstOut);
    }
    
    public Object processIn(Object _in) {
      String in = (String) _in;
      if (in.length() == 0)
        return in;
      String firstIn = in.substring(0, 1);
      return baseLearner.processIn(firstIn) + in.substring(1);
    }
    
    public void toJava(Code code) {
      code.line("if (" + code.s() + ".length() != 0) {");
      code.indent();
      code.line("String rest = " + code.s() + ".substring(1);");
      code.line(code.var + " = " + code.s() + ".substring(0, 1);");
      baseLearner.toJava(code);
      code.line(code.var + " = " + code.s() + "+rest;");
      code.unindent();
      code.line("}");
    }
  }
  
  static Method findMainMethod(Class<?> theClass) {
    for (Method method : theClass.getMethods())
      if (method.getName().equals("main") && method.getParameterTypes().length == 1)
        return method;
    throw new RuntimeException("Method 'main' with 1 parameter not found in " + theClass.getName());
  }
  
  // compile JavaX source and load main class
  static Class<?> compileAndLoadMainClass(String src) throws Exception {
    File srcDir = _x18.TempDirMaker_make();
    File classesDir = _x18.TempDirMaker_make();
    _x18.saveTextFile(new File(srcDir, "main.java").getPath(), src);
    List<File> libraries = new ArrayList<File>();
    File transpiledDir = _x18.topLevelTranslate(srcDir, libraries);
    String javacOutput = _x18.compileJava(transpiledDir, libraries, classesDir);
    System.out.println(javacOutput);
    URL[] urls = {classesDir.toURI().toURL()};
    
    // make class loader
    URLClassLoader classLoader = new URLClassLoader(urls);

    // load main class
    Class<?> mainClass = classLoader.loadClass("main");
    return mainClass;
  }
      
  static Method compileJavaInToOut(Code code) {
    try {
      String java = code.buf.toString();
      String prelude = /*"import java.util.*;\n\n" +*/
        "public class main { public static Object main(Object in) throws Exception {\n";
      String postlude = "\nreturn in;\n}}";
      String src = code.getTranslators() + "\n" + prelude + java + postlude;
      Class<?> mainClass = compileAndLoadMainClass(src);
      return findMainMethod(mainClass);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  static Method findCalcMethod(Class<?> theClass) {
    for (Method method : theClass.getMethods())
      if (method.getName().equals("calc"))
        return method;
    throw new RuntimeException("Method 'calc' not found in " + theClass.getName());
  }
  
  // for simplejava stuff (execute tasks)
  static String execute(String src) {
    try {
      Class<?> mainClass = compileAndLoadMainClass(src);
      Method m = findCalcMethod(mainClass);
      return String.valueOf(m.invoke(null));
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  static void testJava(Case _case, Code code) {
    try {
      Method m = compileJavaInToOut(code);
      
      for (Object[] e : _case.fullExamples) {
        String out = (String) m.invoke(null, e[0]);
        
        if (!e[1].equals(out)) {
          throw new RuntimeException("[fail] Java code on " + structure(e[0]) + " - got: " + structure(out) + " rather than: " + structure(e[1]));
        }
      }
      
      System.out.println("\nGOOD JAVA.");
      _case.goodJava = true;
    } catch (Throwable e) {
      if (showFails)
        e.printStackTrace();
      System.out.println("\nBAD JAVA.");
    }
  }
  
  static void todo() {
    fail("todo");
  }
  
  static class LSwitch extends LearnerImpl {
    Case _case;
    Learner switcher;
    
    LSwitch(Case _case, Learner switcher) {
      this._case = _case;
      this.switcher = switcher;
    }
    
    public void processInOut(Object in, Object out) {
    }
   
    public Object processIn(Object in) {
      int i = Integer.parseInt((String) switcher.processIn(in));
      return _case.combined.get(i-1).winner.processIn(in);
    }
   
    public void toJava(Code code) {
      todo();
    }
  }
 
  /*static class LTryPrevious extends LearnerImpl {
    List<Case> candidates = new ArrayList<Case>();
    
    *() {
      for (int i = caseIdx-1; i >= 0; i--)
        candidates.add(cases.get(i));
    }

    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      for (ListIterator<Case> i = candidates.listIterator(); i.hasNext(); ) {
        Case case = i.next();
        if (case.winner == null || !validate(new String[] {in, out}, case.winner))
          i.remove();
      }
      if (candidates.isEmpty())
        fail("no previous solution found");
    }
  
    public Object processIn(Object in) {
      return candidates.get(0).winner.processIn(in);
    }
  
    public void toJava(Code code) {
      candidates.get(0).winner.toJava(code);
    }
  }*/
  
  static class LMulti extends LearnerImpl {
    static boolean debug;
    List<Learner> candidates = new ArrayList<Learner>();
    
    LMulti(Learner... learners) {
      for (Learner l : learners)
        candidates.add(l);
    }
    
    LMulti(List<Learner> learners) {
      for (Learner l : learners)
        candidates.add(l);
    }

    LMulti(Learner l, List<Learner> ll) {
       candidates.add(l);
      candidates.addAll(ll);
    }
    
    public void processInOut(Object in, Object out) {
      if (debug)
        System.err.println("LMulti candidates: " + candidates.size());
      for (ListIterator<Learner> i = candidates.listIterator(); i.hasNext(); ) {
        Learner l = i.next();
        try {
          l.processInOut(in, out);
        } catch (Throwable e) {
          if (debug) {
            e.printStackTrace();
            System.err.println("Removing candidate: " + structure(l));
          }
          silentException(e);
          i.remove();
        }
      }
      if (debug)
        System.err.println("LMulti candidates now: " + candidates.size());
      if (candidates.isEmpty())
        fail("no candidates left");
    }
    
    public Object processIn(Object in) {
      while (true) { // fails or returns eventually
        Learner l = candidates.get(0);
        if (debug)
          System.err.println("Using candidate: " + structure(l) + ", " + candidates.size() + " left");
        try {
          return l.processIn(in);
        } catch (Throwable e) {
          if (debug) {
            e.printStackTrace();
            System.err.println("Removing candidate: " + structure(l));
          }
          silentException(e);
          candidates.remove(0);
        }
      }
    }
    
    public void tryAgain() {
      candidates.remove(0);
    }
    
    public void toJava(Code code) {
      candidates.get(0).toJava(code);
    }
  }
  
  static String structure(Object o) {
    if (o == null) return "null";
    String name = o.getClass().getName();
    
    StringBuilder buf = new StringBuilder();
    
    if (o instanceof Collection) {
      for (Object x : (Collection) o) {
        if (!(buf.length() == 0)) buf.append(", ");
        buf.append(structure(x));
      }
      return "{" + buf + "}";
    }

    if (o instanceof String)
      return quote((String) o);
    
    // Need more cases? This should cover all library classes...
    if (name.startsWith("java.") || name.startsWith("javax."))
      return String.valueOf(o);
      
    String shortName = o.getClass().getName().replaceAll("^main\\$", "");

    // TODO: go to superclasses too
    Field[] fields = o.getClass().getDeclaredFields();
    int numFields = 0;
    String fieldName = "";
    for (Field field : fields) {
      if ((field.getModifiers() & Modifier.STATIC) != 0)
        continue;
      Object value;
      try {
        value = field.get(o);
      } catch (Exception e) {
        value = "?";
      }
      
      fieldName = field.getName();
      
      // special case for LMulti - show only first (current) candidate
      if (shortName.equals("LMulti") && field.getName().equals("candidates")) {
        fieldName = "candidate";
        value = ((List) value).isEmpty() ? value : ((List) value).get(0);
      }
        
      if (value != null) {
        if (!(buf.length() == 0)) buf.append(", ");
        buf.append(fieldName + "=" + structure(value));
      }
      ++numFields;
    }
    String b = buf.toString();
    if (numFields == 1)
      b = b.replaceAll("^" + fieldName + "=", ""); // drop field name if only one
    String s = shortName;
    if (!(buf.length() == 0))
      s += "(" + b + ")";
    return s;
  }
  
  static class FIsString implements Function {
    static boolean debug;
    
    public Object process(Object _in) {
      String in = (String) _in;
      return in.startsWith("\"") || in.startsWith("[[") ? "1" : "0";
    }
    
    public void toJava_process(Code code) {
      code.assign(code.s() + ".startsWith(\"\\\"\") || " + code.s() + ".startsWith(\"[[\") ? \"1\" : \"0\"");
    }
  }
  
  static class FCommonPrefix implements Function {
    static boolean debug;

    public Object process(Object _in) {
      String in = (String) _in, prefix = null;
      for (String line : toLines(in))
        if (line.length() != 0) {
          prefix = prefix == null ? line : commonPrefix(prefix, line);
          if (debug)
            System.out.println("FCommonPrefix: line=" + quote(line) + ", prefix=" + quote(prefix));
        }
      return prefix;
    }
    
    public void toJava_process(Code code) {
      todo();
    }
  }
  
  static class FCommonSuffix implements Function {
    static boolean debug;

    public Object process(Object _in) {
      String in = (String) _in, suffix = null;
      for (String line : toLines(in))
        if (line.length() != 0) {
          suffix = suffix == null ? line : commonSuffix(suffix, line);
          if (debug)
            System.out.println("FCommonSuffix: line=" + quote(line) + ", suffix=" + quote(suffix));
        }
      return suffix;
    }
    
    public void toJava_process(Code code) {
      todo();
    }
  }
  
  /*static class Pair {
    Object a, b;
    
    public boolean equals(Object o) {
      return o instanceof Pair && a.equals(((Pair) o).a) && b.equals((Pair) o).b);
    }
    
    public int hashCode() {
      return a.hashCode()+b.hashCode()*2;
    }
  }*/
  
  static class Matrix {
    HashMap<Object, Map> dataByCol = new HashMap<Object, Map>();
    
    void put(Object col, Object row, Object value) {
      //data.put(new Pair(col, row), value);
      getCol(col).put(row, value);
    }
    
    Map getCol(Object col) {
      Map map = dataByCol.get(col);
      if (map == null)
        dataByCol.put(col, map = new HashMap());
      return map;
    }
    
    Object get(Object col, Object row) {
      //return data.get(new Pair(col, row));
      return getCol(col).get(row);
    }
    
    Set cols() {
      return dataByCol.keySet();
    }
    
    Set rowsFor(Object col) {
      return getCol(col).keySet();
    }
  }
  
  static class LDistinguishList extends LearnerImpl {
    static boolean debug;
    Function helper;
    int idx;
    Matrix matrix = new Matrix();

    LDistinguishList(Function helper) {
      this.helper = helper;
    }
    
    public void processInOut(Object _in, Object out) {
      List in = (List) _in;
      for (int i = 0; i < in.size(); i++) {
        Object y = helper.process(in.get(i));
        matrix.put(i, y, out);
      }
    }
    
    public Object processIn(Object _in) {
      // find idx
      
      for (Object i : matrix.cols()) {
        Collection ys = matrix.rowsFor(i);
        if (ys.size() > 1) {
          idx = (Integer) i;
          break;
        }
      }
      
      List in = (List) _in;
      Object y = helper.process(in.get(idx));
      return matrix.get(idx, y);
    }
    
    public void toJava(Code code) {
      List ys = new ArrayList(matrix.rowsFor(idx));
      //String v = code.var;
      //code.newVar();
      //String vy = code.var;
      //code.oldVar();
      code.assign(code.list() + ".get(" + idx + ")");
      helper.toJava_process(code);
      
      for (int i = 0; i < ys.size(); i++) {
        Object y = ys.get(i);
        if (i < ys.size())
          code.line((i == 0 ? "" : "else ") + "if (" + quote((String) y) + ".equals(" + code.var + "))");
        else
          code.line("else");
        code.line("  " + code.var + " = " + quote((String) matrix.get(idx, y)) + ";");
      }
    }
  }
  
  static class RunnersUp {
    String expected;
    int bestScore = -1;
    String bestResult;
    Learner winner;
    
    void add(String expected, String result, int score, Learner learner) {
      if (!expected.equals(this.expected) || bestScore == -1 || score < bestScore) {
        bestScore = score;
        bestResult = result;
        winner = learner;
      }
      this.expected = expected;
    }
  }
  
  static List<Case> casesSortedByID() {
    Map<Long, Case> map = new TreeMap<Long, Case>();
    List<Case> rest = new ArrayList<Case>();
    for (Case c : cases)
      if (isSnippetID(c.id))
        map.put(parseSnippetID(c.id), c);
      else
        rest.add(c);
    List<Case> list = new ArrayList<Case>(map.values());
    list.addAll(rest);
    return list;
  }
  
  static int leven(String s, String t) {
  // degenerate cases
  if (s.equals(t)) return 0;
  if (s.length() == 0) return t.length();
  if (t.length() == 0) return s.length();

  // create two work vectors of integer distances
  int[] v0 = new int[t.length() + 1];
  int[] v1 = new int[t.length() + 1];

  // initialize v0 (the previous row of distances)
  // this row is A[0][i]: edit distance for an empty s
  // the distance is just the number of characters to delete from t
  for (int i = 0; i < v0.length; i++)
      v0[i] = i;

  for (int i = 0; i < s.length(); i++)
  {
      // calculate v1 (current row distances) from the previous row v0

      // first element of v1 is A[i+1][0]
      //   edit distance is delete (i+1) chars from s to match empty t
      v1[0] = i + 1;

      // use formula to fill in the rest of the row
      for (int j = 0; j < t.length(); j++)
      {
          int cost = s.charAt(i) == t.charAt(j) ? 0 : 1;
          v1[j + 1] = Math.min(Math.min(v1[j] + 1, v0[j + 1] + 1), v0[j] + cost);
      }

      // copy v1 (current row) to v0 (previous row) for next iteration
      /*for (int j = 0; j < v0.length; j++)
          v0[j] = v1[j];*/
          
      // swap arrays
      int[] v = v1; v1 = v0; v0 = v;
  }

  // for array copying:
  // return v1[t.length()];
  // for array swapping:
  return v0[t.length()];
} // leven (Levenshtein distance function)
  
  // These end up inside the main class

static class LBox extends LearnerImpl {
  static boolean debug;
  Learner middleLearner;
  char topChar, bottomChar;
  
  LBox(Learner middleLearner) {
    this.middleLearner = middleLearner;
  }
  
  // An optimization, but a bit of a dangerous one:
  /*public void forwardSecretExample(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    L<S> l = toLines(out);
    String middle = l.get(2);
    middleLearner.processInOut(in, middle);
  }*/
  
  public void tryAgain() {
    middleLearner.tryAgain();
  }
  
  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    List<String> l = toLines(out);
    String middle = l.get(2);
    middleLearner.processInOut(in, middle);
    topChar = l.get(1).charAt(0);
    bottomChar = l.get(3).charAt(0);
  }
  
  public Object processIn(Object in) {
    String middle = (String) middleLearner.processIn(in);
    return "\n" +
      repeat(topChar, middle.length()) + "\n" +
      middle + "\n" +
      repeat(bottomChar, middle.length()) + "\n";
  }
  
  static String repeat(char c, int n) {
    char[] chars = new char[n];
    for (int i = 0; i < n; i++)
      chars[i] = c;
    return new String(chars);
  }
  
  public void toJava(Code code) {
    todo();
  }
}

static class LBox2 extends LearnerImpl {
  static boolean debug;
  Learner middleLearner;
  char topChar, bottomChar, tlChar, trChar, blChar, brChar;
  
  LBox2(Learner middleLearner) {
    this.middleLearner = middleLearner;
  }
  
  public void tryAgain() {
    middleLearner.tryAgain();
  }
  
  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    List<String> l = toLines(out);
    String middle = l.get(2);
    if (debug)
      System.out.println("Forwarding to middle learner: " + quote(in) + " => " + quote(middle));
    middleLearner.processInOut(in, middle);
    String top = l.get(1), bottom = l.get(3);
    tlChar = top.charAt(0);
    topChar = top.charAt(1);
    trChar = top.charAt(top.length()-1);
    blChar = bottom.charAt(0);
    bottomChar = bottom.charAt(1);
    brChar = bottom.charAt(bottom.length()-1);
  }
  
  public Object processIn(Object in) {
    String middle = (String) middleLearner.processIn(in);
    return "\n" +
      tlChar + repeat(topChar, middle.length()-2) + trChar + "\n" +
      middle + "\n" +
      blChar + repeat(bottomChar, middle.length()-2) + brChar + "\n";
  }
  
  static String repeat(char c, int n) {
    char[] chars = new char[n];
    for (int i = 0; i < n; i++)
      chars[i] = c;
    return new String(chars);
  }
  
  public void toJava(Code code) {
    todo();
  }
} // Box learners
  // These end up inside the main class

static class LEmptyBox extends LearnerImpl {
  static boolean debug;
  Learner inputLearner;
  char c;
  
  LEmptyBox(Learner inputLearner) {
  this.inputLearner = inputLearner;}
  
  public void tryAgain() {
    inputLearner.tryAgain();
  }
  
  public void processInOut(Object in, Object _out) {
    String out = (String) _out;
    List<String> l = toLines(out);
    int w = l.get(1).length(), h = l.size()-1;
    String input = w + "*" + h;
    if (debug)
      System.out.println("LEmptyBox: Feeding to input learner: " + in + " => " + input);
    inputLearner.processInOut(in, input);
    if (debug)
      System.out.println("Input learner: " + structure(inputLearner));
    c = l.get(1).charAt(0);
    if (debug)
      System.out.println("LEmptyBox: c=" + c);
  }
  
  public Object processIn(Object in) {
    String input = (String) inputLearner.processIn(in);
    if (debug)
      System.out.println("LEmptyBox: in=" + in + ", input=" + input);
    String[] split = input.split("\\*");
    int w = Integer.parseInt(split[0]), h = Integer.parseInt(split[1]);
    StringBuilder buf = new StringBuilder();
    buf.append("\n");
    buf.append(repeat(c, w) + "\n");
    for (int y = 1; y < h-1; y++)
      buf.append(c + repeat(' ', w-2) + c + "\n");
    buf.append(repeat(c, w) + "\n");
    return buf.toString();
  }
  
  static String repeat(char c, int n) {
    char[] chars = new char[n];
    for (int i = 0; i < n; i++)
      chars[i] = c;
    return new String(chars);
  }
  
  public void toJava(Code code) {
    todo();
  }
}
 // Empty box learner
  
  // for "find" tasks (e.g. "abcde" to "[[abc]]de")
  static class LFixedSubstring extends LearnerImpl {
    static boolean debug;
    String findMarker1 = "{{", findMarker2 = "}}";
    int i, j;
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      i = out.indexOf(findMarker1);
      j = out.indexOf(findMarker2, i)-2;
      if (debug && j >= 0) {
        boolean correct = in.substring(i, j).equals(out.substring(i+2, j+2));
        System.out.println("LFixedSubstring: i, j = " + i + ", " + j + " " + correct + " " + quote(in.substring(i, j)));
      }
    }
    
    public String processIn(Object _in) {
      String in = (String) _in;
      return in.substring(0, i) + findMarker1 + in.substring(i, j) + findMarker2 + in.substring(j);
    }
  }

  static void print(Object o) {
    System.out.println(o);
  }

  // These end up inside the main class

static class LFixWhitespace extends LearnerImpl {
  static boolean debug;
  Learner base;
  String s;
  
  LFixWhitespace(Learner base) {
  this.base = base;}
  
  public void tryAgain() {
    base.tryAgain();
  }
  
  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    int i = count(in), j = count(out);
    in = in.substring(i);
    s = out.substring(0, j);
    out = out.substring(j);
  if (debug)
      System.out.println("LFixWhitespace: Feeding to input learner: " + in + " => " + out);
    base.processInOut(in, out);
  }
  
  public Object processIn(Object _in) {
    String in = (String) _in;
    int i = count(in);
    in = in.substring(i);
    in = (String) base.processIn(in);
    in = s + in;
    return in;
  }

  int count(String s) {
    int I = 0;
    while (I < s.length () && "\r\n\t ".indexOf(s.charAt(I)) >= 0)
      ++I;
    return I;
  }

}
 // LFixWhiteSpace

  static Object newInstance(Class c, Object... args) { try {
 
    Constructor m = findConstructor(c, args);
    m.setAccessible(true);
    return m.newInstance(args);
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  
  static boolean hasConstructor(Class c, Object... args) {
    for (Constructor m : c.getDeclaredConstructors()) {
      if (!checkArgs(m.getParameterTypes(), args, false))
        continue;
      return true;
    }
    return false;
  }
  
  static Constructor findConstructor(Class c, Object... args) {
    for (Constructor m : c.getDeclaredConstructors()) {
      if (!checkArgs(m.getParameterTypes(), args, false))
        continue;
      return m;
    }
    throw new RuntimeException("Constructor with " + args.length + " matching parameter(s) not found in " + c.getName());
  }
  
  static Class findClass(String name) {
    for (String c : innerClasses)
      if (c.equalsIgnoreCase(name))
        try {
          return Class.forName("main$" + c);
        } catch (ClassNotFoundException e) {
          return null;
        }
    return null;
  }
  
  static boolean isSubclass(Class a, Class b) {
    return b.isAssignableFrom(a);
  }
  
  static boolean checkArgs(Class[] types, Object[] args, boolean debug) {
    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 || types[i].isInstance(args[i]))) {
        if (debug)
          System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
        return false;
      }
    return true;
  }
  
  // finds a fixed element, e.g. a Java token

static class LCertainElement extends LearnerImpl {
  static boolean debug;
  ReversibleFunction f; // e.g. JavaTok
  String element;
  
  LCertainElement(ReversibleFunction f) {
  this.f = f;}
  
  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    Set<String> set = new HashSet<String>(getMarked(out));
    if (debug)
      System.out.println("LCertainElement: set=" + set);
    if (set.size() == 1)
      element = set.iterator().next();
    if (debug)
      System.out.println("LCertainElement: element=" + element);
  }
  
  public Object processIn(Object _in) {
    List<String> l = (List<String>) f.process(_in);
    List<String> l2 = new ArrayList<String>();
    for (String x : l)
      l2.add(x.equals(element) ? "[[" + x + "]]" : x);
    return f.unprocess(l2);
  }
  
  static List<Integer> getFindMarkers2(String s) {
    List<Integer> l = new ArrayList<Integer>();
    int i = 0;
    while (i < s.length()) {
      int j = s.indexOf("[[", i);
      if (j < 0) break;
      int k = s.indexOf("]]", j+2);
      if (k < 0) break;
      l.add(j);
      l.add(k+2);
      i = k+2;
    }
    return l;
  }
  
  static List<String> getMarked(String s) {
    List<Integer> l = getFindMarkers2(s);
    List<String> result = new ArrayList<String>();
    for (int i = 0; i < l.size(); i += 2)
      result.add(s.substring(l.get(i)+2, l.get(i+1)-2));
    return result;
  }
} // LCertainElement
  
  static Class findClassFlex(String p) {
    Class c = findClass(p);
    if (c == null) c = findClass("L" + p);
    if (c == null) c = findClass("F" + p);
    if (c == null) c = findClass("RF" + p);
    return c;
  }
  
  
static class LOneWordChanged extends LearnerImpl {
  static boolean debug;
  Function preprocessor; // e.g. JavaTok
  List<String> lastIn; // only while learning
  String lastOut; // only while learning
  int index;
  String outPattern;

  LOneWordChanged(Function preprocessor) {
  this.preprocessor = preprocessor;}
  
  public void processInOut(Object _in, Object _out) {
    if (debug)
      System.out.println("LOneWordChanged: i/o " + _in + " " + _out);
    String in = (String) _in, out = (String) _out;
    List<String> l = (List<String>) preprocessor.process(_in);
    lastIn = l;
    lastOut = out;
  }
  
  public Object processIn(Object _in) {
    if (debug)
      System.out.println("LOneWordChanged: i " + _in);
    List<String> l = (List<String>) preprocessor.process(_in);
    
    if (outPattern == null) {
      if (l.size() != lastIn.size()) fail();
      for (int i = 0; i < l.size(); i++)
        if (!l.get(i).equals(lastIn.get(i))) {
          index = i;
          String word = lastIn.get(index);
          outPattern = lastOut.replace(word, "{*}");
          
          // delete learning data
          lastIn = null;
          lastOut = null;
          break;
        }
        
      if (outPattern == null) {
        if (debug)
          System.out.println("LOneWordChanged: last=" + lastIn + ", this=" + l);
        fail("not applicable - all words identical");
      }
    }
    if (debug)
      System.out.println("LOneWordChanged: index=" + index + ", outPattern=" + quote(outPattern));

    String word = l.get(index);
    return outPattern.replace("{*}", word);
  }
  
  static List<Integer> getFindMarkers2(String s) {
    List<Integer> l = new ArrayList<Integer>();
    int i = 0;
    while (i < s.length()) {
      int j = s.indexOf("[[", i);
      if (j < 0) break;
      int k = s.indexOf("]]", j+2);
      if (k < 0) break;
      l.add(j);
      l.add(k+2);
      i = k+2;
    }
    return l;
  }
  
  static List<String> getMarked(String s) {
    List<Integer> l = getFindMarkers2(s);
    List<String> result = new ArrayList<String>();
    for (int i = 0; i < l.size(); i += 2)
      result.add(s.substring(l.get(i)+2, l.get(i+1)-2));
    return result;
  }
} // LOneWordChanged
  static class LBla extends LearnerImpl {
  static boolean debug;
  String inPattern, outPattern;

  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    int i = in.indexOf("bla"), j = out.indexOf("bla");
    if (i < 0 || j < 0) fail();
    inPattern = "^" + patternQuote(in.substring(0, i))
      + "(.+)" + patternQuote(in.substring(i+3)) + "$";
    outPattern = Matcher.quoteReplacement(out.substring(0, j))
      + "$1" + Matcher.quoteReplacement(out.substring(j+3));
  }
  
  public Object processIn(Object _in) {
    String in = (String) _in;
    return in.replaceAll(inPattern, outPattern);
  }
} // LBla
  
  static String shorten(String s, int max) {
    return s.length() <= max ? s : s.substring(0, Math.min(s.length(), max)) + "...";
  }
  
  // for stuff like #1000478

static class LIntersperse extends LearnerImpl {
  static boolean debug;
  ReversibleFunction preprocessor; // e.g. JavaTok
  List<String> outPrefix, outSuffix, filler;

  LIntersperse(ReversibleFunction preprocessor) {
  this.preprocessor = preprocessor;}
  
  public void processInOut(Object _in, Object _out) {
    if (debug)
      debug("i/o " + _in + " " + _out);
    List<String> in = (List<String>) ( preprocessor.process(_in));
    List<String> out = (List<String>) ( preprocessor.process(_out));
    int i = out.indexOf(in.get(1));
    outPrefix = out.subList(0, i);
    int j = out.lastIndexOf(in.get(in.size()-2));
    outSuffix = out.subList(j+1, out.size());
    int newLength = j-i+1;
    int realOldLength = (in.size()-1)/2;
    
    /*int intersperse = 0;
    if (realOldLength > 1)
      intersperse = newLength-realOldLength*3-1;*/
    int intersperse = 3; // just assume this for now
    if (realOldLength > 1)
      filler = out.subList(i+1, i+1+intersperse);
    
    if (debug)
      debug("oldLength= " + in.size() + ", newLength=" + newLength +", realOldLength=" + realOldLength + ", intersperse=" + intersperse + ", filler length=" + (filler == null ? 0 : filler.size()));
  }
  
  public Object processIn(Object _in) {
    List<String> l = (List<String>) ( preprocessor.process(_in));
    if (debug)
      debug("i " + structure(l));
    List<String> list = new ArrayList<String>();
    list.addAll(outPrefix);
    if (debug)
      debug("ranging from " + 1 + " to " + (l.size()-2));
    for (int i = 1; i < l.size()-1; i += 2) {
      list.add(l.get(i));
      if (i < l.size()-2)
        list.addAll(filler);
    }
    list.addAll(outSuffix);
    Object out = preprocessor.unprocess(list);
    if (debug)
      debug("output: " + structure(list) + " = " + structure(out));
    return out;
  }
} // LIntersperse
  
  static String getName(Class c) {
    return c.getName().replaceAll("^main\\$", "");
  }
  
  static void keepAlive() {
    Thread _t = new Thread() {
public void run() {
try {

      Object printed = null;
      while (true) {
        Object t = trying;
        Thread.sleep(1000);
        if (t != null && t == trying && printed != t) { // still trying
          System.err.println("* "+ structure(t));
          printed = t;
        } else printed = null;
      }
    } catch (Exception _e) {
  throw _e instanceof RuntimeException ? (RuntimeException) _e : new RuntimeException(_e); } }
};
_t.setDaemon(true);
_t.start();
  }
  
  // for stuff like #1000349

static class LFixedPositions extends LearnerImpl {
  static boolean debug;
  Map<Integer, String> map = new TreeMap<Integer, String>();

  public void processInOut(Object _in, Object _out) {
    // Only looks at out... funny, eh?
    
    String out = (String) ( _out);
    for (int i = 0; i < out.length(); i++) {
      String s = map.get(i);
      String c = out.substring(i, i+1);
      if (s == null)
        map.put(i, c);
      else if (s.equals("")) {
      } else if (!s.equals(c))
        map.put(i, ""); // TILT
    }
    
    for (int i : map.keySet())
      if (i >= out.length())
        map.put(i, "");
  }
  
  public Object processIn(Object _in) {
    String in = (String) ( _in);
    List<String> l = new ArrayList<String>();
    for (int i = 0; i < in.length(); i++)
      l.add(in.substring(i, i+1));
    for (int i : map.keySet()) {
      String s = map.get(i);
      if (!s.equals("")) {
        while (i >= l.size())
          l.add(" ");
        l.set(i, s);
      }
    }
    return join("", l);
  }
} // LFixedPositions
  // for stuff like #1000351

static class LMap extends LearnerImpl {
  static boolean debug;
  Map<String, String> map = new TreeMap<String, String>();

  public void processInOut(Object _in, Object _out) {
    List<String> in = (List<String>) ( _in);
    List<String> out = (List<String>) ( _out);
    
    if (in.size() != out.size()) fail();
    
    for (int i = 0; i < in.size(); i++) {
      String a = in.get(i), b = out.get(i);
      if (!a.equals(b))
        map.put(a, b);
    }
  }
  
  public Object processIn(Object _in) {
    List<String> in = (List<String>) ( _in);
    List<String> out = new ArrayList<String>();
    for (int i = 0; i < in.size(); i++) {
      String a = in.get(i), b = map.get(a);
      out.add(b != null ? b : a);
    }
    return out;
  }
} // LMap
    // learns to exchange common prefixes and suffixes.
  // maybe it's not perfect... see #1000491 for a problem case
  
  static class LPrefixSuffix extends LearnerImpl {
    static boolean debug;
    String prefixIn, suffixIn, prefixOut, suffixOut;
    
    public void processInOut(Object _in, Object _out) {
      String in = (String) _in, out = (String) _out;
      updateIn(in);
      prefixOut = prefixOut == null ? out : commonPrefix(prefixOut, out);
      suffixOut = suffixOut == null ? out : commonSuffix(suffixOut, out);
      if (debug)
        printState("processInOut(" + quote(in) + ", " + quote(out) + ")");
    }
    
    void updateIn(String in) {
      prefixIn = prefixIn == null ? in : commonPrefix(prefixIn, in);
      suffixIn = suffixIn == null ? in : commonSuffix(suffixIn, in);
      if (debug)
        printState("updateIn(" + quote(in) + ")");
    }

    public String processIn(Object _in) {
      String in = (String) _in;
      //System.out.println("[before last info] " + quote(prefixIn) + " " + quote(suffixIn) + " " + quote(prefixOut) + " " + quote(suffixOut));
      //System.out.println("[last info] " + quote(in));
      
      // use latest information
      String p = prefixIn, s = suffixIn;
      updateIn(in);
      prefixOut = prefixOut.substring(0, prefixOut.length()-(p.length()-prefixIn.length()));
      suffixOut = suffixOut.substring(s.length()-suffixIn.length());
      
      //System.out.println("[after last info] " + quote(prefixIn) + " " + quote(suffixIn) + " " + quote(prefixOut) + " " + quote(suffixOut));
      String core = in.substring(prefixIn.length(), in.length()-suffixIn.length());
      return prefixOut + core + suffixOut;
    }
    
    public void toJava(Code code) {
      if (prefixIn.length() != 0 || suffixIn.length() != 0)
        code.line(code.var + " = ((String) " + code.var + ").substring(" + prefixIn.length() + ", " + code.s() + ".length()-" + suffixIn.length() + ");");
      if (prefixOut.length() != 0 || suffixOut.length() != 0)
        code.line(code.var + " = " + quote(prefixOut) + " + " + code.var + " + " + quote(suffixOut) + ";");
    }
    
    void printState(String text) {
      System.out.println(text);
      printVars();
    }
  }
  
 // LPrefixSuffix
  // learns to remove input suffixes.

static class LRemoveInputSuffix extends LearnerImpl {
  static boolean debug;
  String suffix;
  static boolean failFast = false;
  
  public void processInOut(Object _in, Object _out) {
    String in = (String) _in, out = (String) _out;
    if (!in.startsWith(out)) fail();
    suffix = overwrite(suffix, in.substring(out.length()));
  }

  public String processIn(Object _in) {
    String in = (String) _in;
    if (!in.endsWith(suffix)) if (failFast) fail(); else return in;
    return in.substring(0, in.length()-suffix.length());
  }
}
 // LRemoveInputSuffix
  
  static <T> T overwrite(T existing, T newValue) {
    if (existing != null && !existing.equals(newValue))
      fail("Overwrite");
    return newValue;
  }
  
  static void getPass() { try {
 
    if (user != null) {
      File pwFile = new File(_x18.userHome(), ".javax/pw-" + user);
      if (pass == null) {
        List<String> lines = toLines(readTextFile(pwFile, ""));
        if (!lines.isEmpty())
          pass = lines.get(0).trim();
        if ("".equals(pass)) pass = null;
        //System.out.println("Pass: " + quote(pass));
        if (pass != null)
          System.out.println("Password read from " + pwFile.getAbsolutePath());
      }
      if (pass == null)
        System.out.println("You can put your password in: " + pwFile.getAbsolutePath());
    }
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  
  static void editSnippetText(String docID, String newText, String editInfo) { try {
 
    getPass();
    System.out.println("Editing " + docID);
    URL url = new URL("http://tinybrain.de:8080/tb-int/auto-edit.php");
    String postData =
        "user=" + urlencode(user)
      + "&pass=" + urlencode(pass)
      + "&id=" + urlencode(docID)
      + "&text=" + urlencode(newText)
      + "&editinfo=" + urlencode(editInfo);
    System.out.println(postData);
    String result = doPost(postData, url.openConnection(), url);
    System.out.println("Edit result: " + result);
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  
  static String urlencode(String s) { try {
 
    return URLEncoder.encode(unnull(s), "UTF-8");
  
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
  
  static String doPost(String urlParameters, URLConnection conn, URL url) throws IOException {
    // connect and do POST
    conn.setDoOutput(true);

    OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
    writer.write(urlParameters);
    writer.flush();

    String contents = loadPage(conn, url);
    writer.close();
    return contents;
  }
  
  static class FBeforeColon extends FunctionImpl {
  public Object process(Object _in) {
    String in = (String) ( _in);
    return in.substring(0, in.indexOf(':'));
  }
} // FBeforeColon
  static class FAfterColon extends FunctionImpl {
  public Object process(Object _in) {
    String in = (String) ( _in);
    return in.substring(in.indexOf(':')+1);
  }
} // FAfterColon
  static class FUnquote extends FunctionImpl {
  public Object process(Object _in) {
    String in = (String) ( _in);
    return unquote(in);
  }
} // FUnquote
  static class LCombineTwoFunctions extends LearnerImpl {
  static boolean debug;
  Function f, g;

  public void processInOut(Object in, Object out) {
    if (f != null) return;
    List<Function> functions = allFunctions();
    
    // simple version without really checking multiple candidates
    for (Function f : functions) {
      Object o = tryProcess(f, in);
      if (o != null) {
        if (debug)
          debug("in=" + structure(in) + ", f=" + structure(f) + ", o=" + structure(o));
        for (Function g : functions) {
          Object x = tryProcess(g, o);
          if (out.equals(x)) {
            if (debug)
              debug("bingo! " + structure(g));
            this.f = f;
            this.g = g;
            return;
          }
        }
      }
    }
  }
  
  public Object processIn(Object in) {
    return g.process(f.process(in));
  }
  
  static Object tryProcess(Function f, Object in) {
    try {
      return f.process(in);
    } catch (Throwable e) {
      return null;
    }
  }
} // LCombineTwoFunctions
  // extensive version with full search
    
static class LCombineTwoFunctions2 extends LearnerImpl {
  static boolean debug;
  Stepper stepper;
  List<Object[]> examples = new ArrayList<Object[]>();
  
  public void processInOut(Object in, Object out) {
    examples.add(new Object[] {in, out});
    
    if (stepper == null)
      stepper = new Stepper(allFunctions());

    while (!stepper.ended()) {
      if (check(stepper.current()))
        return; // ok, keep
      else
        stepper.step();
    }
    
    fail();
  }
  
  boolean check(Function[] fg) {
    if (debug) debug("Checking " + structure(fg));
    for (Object[] e : examples) {
      Object o = tryProcess(fg[0], e[0]);
      if (o != null) {
        Object x = tryProcess(fg[1], o);
        if (e[1].equals(x))
          continue; // example ok
      }
      return false;
    }
    return true; // all examples ok
  }
  
  public Object processIn(Object in) {
    Function[] fg = stepper.current();
    return fg[1].process(fg[0].process(in));
  }
  
  static Object tryProcess(Function f, Object in) { try {
 
    return f.process(in);
  
} catch (Throwable __e) { return null; }}
  
  static class Stepper {
    List<Function> functions;
    int i1, i2;
    
    Stepper(List<Function> functions) {
  this.functions = functions;}
    
    boolean ended() {
      return i1 >= functions.size();
    }
    
    Function[] current() {
      return new Function[] {functions.get(i1), functions.get(i2)};
    }
    
    void step() {
      if (i2 < functions.size()) ++i2;
      else { ++i1; i2 = 0; }
    }
  }
} // LCombineTwoFunctions2
  
  static List<Function> allFunctions() {
    List<Function> list = new ArrayList<Function>();
    for (String s : innerClasses) {
      Class c = findClass(s);
      if (c == null) continue;
      if (isSubclass(c, Function.class) && hasConstructor(c))
        list.add((Function) newInstance(c));
    }
    return list;
  }

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

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

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

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

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

  public static String readTextFile(String fileName, String defaultContents) throws IOException {
    return loadTextFile(fileName, defaultContents);
  }

  public static String readTextFile(File file, String defaultContents) throws IOException {
    return loadTextFile(file.getPath(), defaultContents);
  }


 public static List<String> toLines(String s) {
    List<String> lines = new ArrayList<String>();
    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;
  }

  public static String fromLines(List<String> lines) {
    StringBuilder buf = new StringBuilder();
    for (String line : lines) {
      buf.append(line).append('\n');
    }
    return buf.toString();
  }

  static boolean preferCached = false;

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

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

  public static long parseSnippetID(String snippetID) {
    return Long.parseLong(shortenSnippetID(snippetID));
  }

  private 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 snippetID;
  }

  public static boolean isSnippetID(String snippetID) {
    snippetID = shortenSnippetID(snippetID);
    return isInteger(snippetID) && Long.parseLong(snippetID) != 0;
  }

  public static boolean isInteger(String s) {
    return Pattern.matches("\\-?\\d+", s);
  }

  public static String loadSnippet(long snippetID, boolean preferCached) throws IOException {
    if (preferCached) {
      initSnippetCache();
      String text = DiskSnippetCache_get(snippetID);
      if (text != null)
        return text;
    }

    String text;
    try {
      URL url = new URL("http://tinybrain.de:8080/getraw.php?id=" + snippetID);
      text = loadPage(url);
    } catch (FileNotFoundException e) {
      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"));
  }
  

  public static String commonPrefix(String a, String b) {
    int i = 0;
    while (i < a.length() && i < b.length() && a.charAt(i) == b.charAt(i))
      ++i;
    return a.substring(0, i);
  }


  public static String commonSuffix(String a, String b) {
    int i = 0;
    while (i < a.length() && i < b.length() && a.charAt(a.length()-1-i) == b.charAt(b.length()-1-i))
      ++i;
    return a.substring(a.length()-i);
  }


  public static String quote(String s) {
    if (s == null) return "null";
    return "\"" + s.replace("\\", "\\\\").replace("\"", "\\\"").replace("\r", "\\r").replace("\n", "\\n") + "\"";
  }

  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();
  }


  public static byte[] loadBinaryPage(URLConnection con) throws IOException {
    //setHeaders(con);
    ByteArrayOutputStream buf = new ByteArrayOutputStream();
    InputStream inputStream = con.getInputStream();
    int n = 0;
    while (true) {
      int ch = inputStream.read();
      if (ch < 0)
        break;
      buf.write(ch);
      if (++n % 100000 == 0)
        System.err.println("  " + n + " bytes loaded.");
    }
    inputStream.close();
    return buf.toByteArray();
  }


  /** writes safely (to temp file, then rename) */
  public static void saveBinaryFile(String fileName, byte[] contents) throws IOException {
    File file = new File(fileName);
    File parentFile = file.getParentFile();
    if (parentFile != null)
      parentFile.mkdirs();
    String tempFileName = fileName + "_temp";
    FileOutputStream fileOutputStream = new FileOutputStream(tempFileName);
    fileOutputStream.write(contents);
    fileOutputStream.close();
    if (file.exists() && !file.delete())
      throw new IOException("Can't delete " + fileName);

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


  public static String loadPage(String url) throws IOException {
    if (url.indexOf("://") < 0)
      url = "http://" + url;
    return loadPage(new URL(url));
  }
  
  public static String loadPage(URL url) throws IOException {
    System.out.println("Loading: " + url.toExternalForm());
    URLConnection con = url.openConnection();
    return loadPage(con, url);
  }

  public static String loadPage(URLConnection con, URL url) throws IOException {
    String contentType = con.getContentType();
    if (contentType == null)
      throw new IOException("Page could not be read: " + url);
    //Log.info("Content-Type: " + contentType);
    String charset = loadPage_guessCharset(contentType);
    Reader r = new InputStreamReader(con.getInputStream(), charset);
    StringBuilder buf = new StringBuilder();
    while (true) {
      int ch = r.read();
      if (ch < 0)
        break;
      //Log.info("Chars read: " + buf.length());
      buf.append((char) ch);
    }
    return buf.toString();
  }
  
  static String loadPage_guessCharset(String contentType) {
    Pattern p = Pattern.compile("text/html;\\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 Class<?> getClass(String name) {
    try {
      return Class.forName(name);
    } catch (ClassNotFoundException e) {
      return null;
    }
  }

  static Object call(Object o, String method, Object... args) {
    try {
      Method m = call_findMethod(o, method, args, false);
      m.setAccessible(true);
      return m.invoke(o, args);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  static Object call(Class c, String method, Object... args) {
    try {
      Method m = call_findStaticMethod(c, method, args, false);
      m.setAccessible(true);
      return m.invoke(null, args);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  static Method call_findStaticMethod(Class c, String method, Object[] args, boolean debug) {
    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 || types[i].isInstance(args[i]))) {
        if (debug)
          System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
        return false;
      }
    return true;
  }



  static void set(Class c, String field, Object value) {
    try {
      Field f = set_findStaticField(c, field);
      f.setAccessible(true);
      f.set(null, value);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  static Field set_findStaticField(Class<?> c, String field) {
    for (Field f : c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
  }

static String patternQuote(String s) {
  return s.length() == 0 ? "" : Pattern.quote(s);
}

  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));
  }


  static String unnull(String s) {
    return s == null ? "" : s;
  }
}

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

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

	Java20() {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

		put("MULTILINE_LITERAL2", new Concatenation(
			new Singleton("[=["), new Concatenation(
			new Repetition(
				new Union(
					new NonMatch("]"),
					new Concatenation(new Singleton("]"), new Union(
				    new NonMatch("="),
				    new Concatenation(new Singleton("="), new NonMatch("]"))))
			  ), 0, INFINITY
			),
			new Singleton("]=]")
		)));

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

		f = i = s();

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

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

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

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

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

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

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

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

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

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

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

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

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

	if (I.isEmpty()) {

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

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

	Integer
		f = null;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

}