anchor.diff:  
   find_all_by_email(Name) -> 
     db:read({user, Name}).
  +
  +find_by_token(Token) ->
  +  case db:match(#user{token = Token, _='_'}) of
  +    [U|_] -> U;
  +    _ -> []
  +  end.
   
   % Does this user exist?
   exist(Name) ->
  
positive.code:   ])),
    create(User#user{token = NewToken}).
  
  create_new_token_for(Email, Password) ->
    case find_by_email(Email) of
      [] -> error;
  
negative.code:   update/1,
    delete/1, 
    create_new_token_for/1, create_new_token_for/2,
    find_by_token/1,
    is_user_token/2,
    new/1
  ]).
  
  