SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "f"
    GENERIC_PARAM_LIST
      L_ANGLE "<"
      TYPE_PARAM
        NAME
          IDENT "T"
      R_ANGLE ">"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    WHERE_CLAUSE
      WHERE_KW "where"
      WHITESPACE " "
      WHERE_PRED
        PATH_TYPE
          PATH
            PATH_SEGMENT
              NAME_REF
                IDENT "T"
        COLON ":"
        WHITESPACE " "
        TYPE_BOUND_LIST
          TYPE_BOUND
            QUESTION "?"
            FOR_TYPE
              FOR_KW "for"
              GENERIC_PARAM_LIST
                L_ANGLE "<"
                R_ANGLE ">"
              WHITESPACE " "
              PATH_TYPE
                PATH
                  PATH_SEGMENT
                    NAME_REF
                      IDENT "Sized"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        R_CURLY "}"
  WHITESPACE "\n"
