(Program
  (Module
    (Identifier))
  (Function
    (Identifier)
    (Other "type_declaration"
      (TypeDecl
        (Identifier)
        (StructTy
        { (FieldDecl
            (Identifier)
            (Identifier))
        ->(FieldDecl
            (Other "identifier_list"
              (Identifier)
              (Identifier))
            (Identifier)) })))))