anchor.diff:  %%----------------------------------------------------------------------------
   %% Internal functions
   %%----------------------------------------------------------------------------
  +
  +posts_list(Binary) ->
  +    posts_list(Binary, []).
  +
  +posts_list(<<>>, Acc) ->
  +    Acc;
  +posts_list(Binary, Acc) ->
  +    [Line, Rest] = binary:split(Binary, <<"\n">>), %% does this work correctly with UTF-8?
  +    [Id, Text] = binary:split(Line, <<" ">>),
  +    _Terms = dk_pp:terms(Text, "en"),
  +    posts_list(Rest, [Id | Acc]).
   
   %% @private
   '_add_doc'(DomId, CatId, DocId, Doc) ->
  
positive.code: -module(dk_in).
  
  %% API
  -export([add_doc/4]).
  
  %% For internal use only
  -export(['_add_doc'/4]).
  
negative.code: %%----------------------------------------------------------------------------
  %% API
  %%----------------------------------------------------------------------------
  
  create_index(_DomId, _CatId, File) ->
      %% add domain
      %% add cat
      %% open file
      {ok, Binary} = file:read_file(File),
      %% build "posts list" (i.e. [{Term, DocId}, {Term, DocId}, ...])
      posts_list(Binary).
  
  %% @doc Adds a document.
  add_doc(DomId, CatId, DocId, Doc) ->
  