static <A> F1<S, A> codeWithHintsToFunctionOnString(S code, S hints) {
  code = trim(code);
  Class c;
  S methodName;
  if (isIdentifier(code)) { // name of standard function
    c = loadFunctions_cached_withInit(code);
    methodName = code;
  } else {
    c = veryQuickJava("sO calc(S s) {\n" + tok_addReturn(code) + "\n}");
    methodName = 'calc;
  }
  
  final Method m = findMethod_precise(c, code, "");
  if (m == null) fail("Not a method on a string: " + code);
  ret func(S s) -> A { (A) invokeMethod(m, null, s) };
}