SOURCE_FILE
  MACRO_DEF
    MACRO_KW "macro"
    WHITESPACE " "
    NAME
      IDENT "m"
    TOKEN_TREE
      L_PAREN "("
      DOLLAR "$"
      IDENT "i"
      COLON ":"
      IDENT "ident"
      R_PAREN ")"
    WHITESPACE " "
    TOKEN_TREE
      L_CURLY "{"
      R_CURLY "}"
  WHITESPACE "\n"
