anchor.diff:                               end, sort(St#leex.warnings))
                end, report_warnings, St#leex.opts).
   
  +-spec add_error(_, #leex{}) -> no_return().
   add_error(E, St) ->
       add_error(St#leex.xfile, E, St).
   
  
positive.code: -export([compile/3,file/1,file/2,format_error/1]).
  
  -import(lists, [member/2,reverse/1,sort/1,delete/2,
                  keysort/2,keydelete/3,keyfind/3,
                  map/2,foldl/3,foreach/2,flatmap/2]).
  -import(string, [substr/2,substr/3,span/2]).
  -import(ordsets, [is_element/2,add_element/2,union/2]).
  
negative.code:                  "unterminated " ++ Cs;
               {illegal_char,Cs} ->
                   "illegal character " ++ Cs;
  %%           {posix_cc,What} ->
  %%               ["illegal POSIX character class ",io_lib:write_string(What)];
               {char_class,What} ->
                   ["illegal character class ",io_lib:write_string(What)]
           end,
  