You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: ft_documentationindex.m
    path of file: ./repos/bspm/thirdparty/spm12/external/fieldtrip
    
    the code of the file until where you have to start completion: function index = ft_documentationindex(filename)

% FT_DOCUMENTATIONINDEX is a function to maintain the online documentation. 
%
% Normal users will not be calling this function, but will rather look at
% http://fieldtrip.fcdonders.nl/reference/index where the output of this
% function can be found.
%
% See FT_DOCUMENTATIONREFERENCE

% Copyright (C) 2008-2012, Robert Oostenveld
%
% This file is part of FieldTrip, see http://www.ru.nl/neuroimaging/fieldtrip
% for the documentation and details.
%
%    FieldTrip is free software: you can redistribute it and/or modify
%    it under the terms of the GNU General Public License as published by
%    the Free Software Foundation, either version 3 of the License, or
%    (at your option) any later version.
%
%    FieldTrip is distributed in the hope that it will be useful,
%    but WITHOUT ANY WARRANTY; without even th
    
function is available in the [[:reference|reference documentation]].\n\n');
fprintf(fid, 'This index to the reference documentation is automatically generated from the MATLAB code every day. Therefore you should not edit this page manually, since your changes would be overwritten automatically. If you want to suggest corrections to the documentation, please send them by email to the mailing list or to one of the main developers (see [[:contact]]).\n\n');
for i=1:size(index,1)
  fprintf('%s -- %s -- %s\n', index{i,2}, index{i,3}, index{i,1});
  if isempty(index{i,1})
    continue;
  elseif length(index{i,2})<5
    continue;
  end
  thisletter = index{i,2}(5);
  while currletter<thisletter
    currletter = currletter + 1;
    fprintf(fid, '===== %s =====\n\n', upper(char(currletter)));
  end
  fprintf(fid, '** %s ** // %s //\\\\\n', index{i,2}, index{i,1});
  
  % do postprocessing to make sure we don't mess up dokuwiki layout
  % '' is a markup instruction for dokuwiki so escape by replacing it
  % with %%''%%
  index{i,3} = strrep(index{i,3},'''''','%%''''%%');
  
  fprintf(fid, '%s\n\n', index{i,3});
end