anchor.diff:  reg4([$(|S0]) ->
       case reg(S0) of
   	{R,[$)|S1]} -> {{group, R},S1};
  -	{R,S} -> throw({error,{unterminated,"("}})
  +	{_R,_S} -> throw({error,{unterminated,"("}})
       end;
   reg4([$\\,O1,O2,O3|S]) when
     O1 >= $0, O1 =< $7, O2 >= $0, O2 =< $7, O3 >= $0, O3 =< $7 ->
  
positive.code: 
  first_match(RE, S, St) when S /= [] ->
      case re_apply(S, St, RE) of
  	{match,P,Rest,_Groups} -> {St,P-St};
  	nomatch -> first_match(RE, tl(S), St+1)
      end;
  first_match(RE, [], St) -> nomatch.
  
  %% -type matches(String, RegExp) -> {match,[{Start,Length}]} | {error,E}.
  %%  Return the all the non-overlapping matches of RegExp in String.
  
negative.code: %% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
  %% AB. All Rights Reserved.''
  %% 
  %%     Id
  %%
  -module(group_regexp).
  
  