anchor.diff:      Limit = if Limit0 < 50 -> Limit0; true -> 50 end,
       Skip = couch_util:get_value(skip, Opts, 0),
       Fields = couch_util:get_value(fields, Opts, all_fields),
  -
       {ok, #cursor{
           db = Db,
           index = Index,
  
positive.code:     limit,
      skip,
      user_fun,
      user_acc
  }).
  
  
  
negative.code: 
  
  apply_user_fun(CAcc, Doc) ->
      FinalDoc = mango_fields:extract(Doc, CAcc#cacc.fields),
      #cacc{
          user_fun = UserFun,
          user_acc = UserAcc
      } = CAcc,
      case UserFun({row, FinalDoc}, UserAcc) of
          {ok, NewUserAcc} ->
              CAcc#cacc{user_acc = NewUserAcc};
          {stop, NewUserAcc} ->
  