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