==================
Function declaration
==================

module default {
    function foo(s: str) -> str
      using (select s ++ <str>len(a));
}

---

(source_file
  (module
    (identifier)
    (schema_declarations
      (function
        (identifier)
        (argspec
          (identifier))
        (returnspec
          (type))
        (using
          (edgeql_fragment))))))
