anchor.diff:                chunk_summary/0,
                 chunk_pos/0,
                 chunk_size/0,
  +              csum_tag/0,
                 error_general/0,
                 epoch_csum/0,
                 epoch_num/0,
  
positive.code: -type read_opts()   :: #read_opts{}.
  -type read_opts_x() :: 'undefined' | 'noopt' | 'none' | #read_opts{}.
  
  %% Tags that stand for how that checksum was generated. See
  %% machi_util:make_tagged_csum/{1,2} for further documentation and
  %% implementation.
  -type csum_tag()    :: none | client_sha | server_sha | server_regen_sha.
  
  -export_type([
                append_opts/0,
                chunk/0,
  
negative.code: -type chunk_summary() :: {file_offset(), chunk_size(), chunk_bin(), chunk_cstrm()}.
  -type chunk_pos()   :: {file_offset(), chunk_size(), file_name_s()}.
  -type chunk_size()  :: non_neg_integer().
  
  %% Tags that stand for how that checksum was generated. See
  %% machi_util:make_tagged_csum/{1,2} for further documentation and
  %% implementation.
  -type csum_tag()    :: none | client_sha | server_sha | server_regen_sha.
  
  -type error_general() :: 'bad_arg' | 'wedged' | 'bad_checksum'.
  -type epoch_csum()  :: binary().
  -type epoch_num()   :: -1 | non_neg_integer().
  