// requires class _javax and ctex

static String execute(String src) ctex {

  Class<?> mainClass = execute_compileAndLoadMainClass(src);

  Method m = execute_findCalcMethod(mainClass);

  return String.valueOf(m.invoke(null));

}

// compile JavaX source and load main class

static Class<?> execute_compileAndLoadMainClass(String src) tex {

  File srcDir = _javax.TempDirMaker_make();

  File classesDir = _javax.TempDirMaker_make();

  _javax.saveTextFile(new File(srcDir, "main.java").getPath(), src);

  new List<File> libraries;

  _javax.safeTranslate = true;

  File transpiledDir = _javax.topLevelTranslate(srcDir, libraries);

  String javacOutput = _javax.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 execute_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());

}