function DFSA = read_dfsa(fname)
if strcmp(inputname(1),'fstr')
  % this is why i love matlab so much
  fstr = fname;
else
  fstr = file2str(fname);
end

fstr = lower(fstr);
fstr = strrep(fstr,[char(13) char(10)],char(10));
fstr = strrep(fstr,'final','accepting');
fstr = strrep(fstr,'initial','start');


DFSA.ALF = get_alf(fstr);
%DFSA.Q = get_states(fstr,'the states');
DFSA.Q = get_states(fstr,'states');
DFSA.F = get_states(fstr,'accepting');
q0 = get_states(fstr,'start');
if (length(q0)~=1)
  error('bad start state entry');
end
DFSA.q0 = q0;
dead = get_states(fstr,'dead');
DFSA = setdelta(DFSA,fstr,dead);

if ~all(all(DFSA.delta))
  warning('DFSA is incomplete');
end
return

function ALF = get_alf(fstr)
if ~isempty(findstr(fstr,'alphabet'))
  cc = text2cell_adv(fstr,'','"',1);
  ALF = cc{2};
else
  % must go the harder route
  % look at all the letters that govern transitions
  i = findstr(fstr,'(');
  fstr=fstr(i:end);
  cc = text2cell_adv(fstr,'',char(10));
  ALF = [];
  for j=1:length(cc)
    % ignore entries not containing '->'
    if ~isempty(findstr(cc{j},'->'))
      dd = text2cell_adv(cc{j},'',' (),->0123456789');
      ALF = [ALF dd{1}];
    end
  end
  ALF = unique(ALF);
end
return

function qq = get_states(fstr,key)
i = findstr(fstr,key);
fstr=fstr(i:end);
i = findstr(fstr,char(10));
fstr = fstr(1:i);
cc = text2cell_adv(fstr,'0123456789','');
qq = [];
for j=1:length(cc)
    qq(end+1) = str2num(cc{j});
end
qq = sort(qq);
return

function DFSA = setdelta(DFSA,fstr,dead)
DFSA = init_ddelta(DFSA);
i = findstr(fstr,'(');
fstr=fstr(i:end);
cc = text2cell_adv(fstr,'',char(10));
for j=1:length(cc)
  % ignore entries not containing '->'
  if ~isempty(findstr(cc{j},'->'))
    dd = text2cell_adv(cc{j},[DFSA.ALF '0123456789'],'');
    q1 = str2num(dd{1});
    s = dd{2};
    q2 = str2num(dd{3});
    for j=1:length(s)
      DFSA = set_ddelta(DFSA,q1,s(j),q2);
    end
  end
end
if ~isempty(dead)
  for q=dead
    for s=DFSA.ALF
      DFSA = set_ddelta(DFSA,q,s,q);
    end
  end
end
return

DFSA = init_ddelta(DFSA);

for j=1:length(str)
  q1 = j;
  q2 = j+1;
  %s = double(str(j));
  s = str(j);
  DFSA = set_ddelta(DFSA,q1,s,q2);
  %for t=setdiff(double(DFSA.ALF),s)
  for t=setdiff(DFSA.ALF,s)
    DFSA = set_ddelta(DFSA,q1,t,qd);
  end
end

%for t=double(DFSA.ALF)
for t=DFSA.ALF
  DFSA = set_ddelta(DFSA,qd,t,qd);
  DFSA = set_ddelta(DFSA,qf,t,qd);
end

return