SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "foo"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE "\n    "
        EXPR_STMT
          BLOCK_EXPR
            ATTR
              POUND "#"
              L_BRACK "["
              META
                PATH
                  PATH_SEGMENT
                    NAME_REF
                      IDENT "A"
              R_BRACK "]"
            WHITESPACE " "
            STMT_LIST
              L_CURLY "{"
              WHITESPACE " "
              TRY_EXPR
                ATTR
                  POUND "#"
                  L_BRACK "["
                  META
                    PATH
                      PATH_SEGMENT
                        NAME_REF
                          IDENT "B"
                  R_BRACK "]"
                WHITESPACE " "
                MACRO_EXPR
                  MACRO_CALL
                    PATH
                      PATH_SEGMENT
                        NAME_REF
                          IDENT "bar"
                    BANG "!"
                    TOKEN_TREE
                      L_PAREN "("
                      R_PAREN ")"
                QUESTION "?"
              WHITESPACE " "
              R_CURLY "}"
        WHITESPACE "\n    "
        REF_EXPR
          ATTR
            POUND "#"
            L_BRACK "["
            META
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "C"
            R_BRACK "]"
          WHITESPACE " "
          AMP "&"
          TUPLE_EXPR
            L_PAREN "("
            R_PAREN ")"
        WHITESPACE "\n"
        R_CURLY "}"
  WHITESPACE "\n"