SOURCE_FILE
  ERROR
    IF_KW "if"
  WHITESPACE " "
  ERROR
    MATCH_KW "match"
  WHITESPACE "\n\n"
  STRUCT
    STRUCT_KW "struct"
    WHITESPACE " "
    NAME
      IDENT "S"
    WHITESPACE " "
    RECORD_FIELD_LIST
      L_CURLY "{"
      R_CURLY "}"
error 0: expected an item
error 3: expected an item