SOURCE_FILE
  MACRO_CALL
    PATH
      PATH_SEGMENT
        NAME_REF
          IDENT "macro_rules"
    BANG "!"
    WHITESPACE " "
    TOKEN_TREE
      L_CURLY "{"
      R_CURLY "}"
  WHITESPACE "\n"
  MACRO_CALL
    PATH
      PATH_SEGMENT
        NAME_REF
          IDENT "macro_rules"
    BANG "!"
    WHITESPACE " "
    TOKEN_TREE
      L_PAREN "("
      R_PAREN ")"
    SEMICOLON ";"
  WHITESPACE "\n"
  MACRO_CALL
    PATH
      PATH_SEGMENT
        NAME_REF
          IDENT "macro_rules"
    BANG "!"
    WHITESPACE " "
    TOKEN_TREE
      L_BRACK "["
      R_BRACK "]"
    SEMICOLON ";"
  WHITESPACE "\n"
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "main"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE "\n    "
        LET_STMT
          LET_KW "let"
          WHITESPACE " "
          IDENT_PAT
            NAME
              IDENT "foo"
          WHITESPACE " "
          EQ "="
          WHITESPACE " "
          MACRO_EXPR
            MACRO_CALL
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "macro_rules"
              BANG "!"
              TOKEN_TREE
                L_PAREN "("
                R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE "\n"
        R_CURLY "}"
  WHITESPACE "\n"
