var output, print = function(string) {
  process.stdout.write('' + string);
};

(function(program, execJS) { execJS(program) })(
  function(callback) { #{source} },
  function(program) {
    program(function(err, result){
      if(err) {
        print(JSON.stringify(['err', err, err.stack]));
      } else {
        if (typeof result == 'undefined' && result !== null) {
          print('["ok"]');
        } else {
          print(JSON.stringify(['ok', result]));
        }
      }
    });
  }
);