// optionally convert expression to return statement
static S tok_addReturn(L<S> tok) {
  S lastToken = get(tok, l(tok)-2);
  //print("addReturn: " + structure(tok) + ", lastToken: " + quote(lastToken));
  if (eq(lastToken, "}") || eq(lastToken, ";")) ret join(tok);
  ret "ret " + join(tok) + ";";
}

static S tok_addReturn(S s) {
  ret tok_addReturn(javaTok(s));
}