// compile JavaX source, load classes & return main class

  // src can be a snippet ID or path to sources dir

  // TODO: record injection?

  static Class<?> hotwire(String src) {

    try {

      Class j = getJavaX();

      synchronized(j) { // hopefully this goes well...

        List<File> libraries = new ArrayList<File>();

        File srcDir = (File) call(j, "transpileMain", src, libraries);

        if (srcDir == null)

          fail("transpileMain returned null (src=" + quote(src) + ")");

        Object androidContext = get(j, "androidContext");

        if (androidContext != null)

          return (Class) call(j, "loadx2android", srcDir, src);

        File classesDir = (File) call(j, "TempDirMaker_make");

        String javacOutput = (String) call(j, "compileJava", srcDir, libraries, classesDir);

        System.out.println(javacOutput);

        URL[] urls = new URL[libraries.size()+1];

        urls[0] = classesDir.toURI().toURL();

        for (int i = 0; i < libraries.size(); i++)

          urls[i+1] = libraries.get(i).toURI().toURL();

        // make class loader

        URLClassLoader classLoader = new URLClassLoader(urls);

        // load & return main class

        Class<?> theClass = classLoader.loadClass("main");

        callOpt(j, "registerSourceCode", theClass, loadTextFile(new File(srcDir, "main.java")));

        call(j, "setVars", theClass, isSnippetID(src) ? src : null);

        if (isSnippetID(src))

          callOpt(j, "addInstance", src, theClass);

        if (!_inCore())

          hotwire_copyOver(theClass);

        return theClass;

      }

    } catch (Exception e) {

      throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);

    }

  }