Added virtual symbol SymVariable translated from general real SymIdentifier symbol

operator-dot.go

@@ -67,20 +67,8 @@ func evalDot(ctx ExprContext, self *term) (v any, err error) {
 				err = fmt.Errorf("key %v does not belong to the dictionary", rightValue)
 			}
 		}
-	// case *dataCursor:
-	// 	if indexTerm.symbol() == SymIdentifier {
-	// 		opName := indexTerm.source()
-	// 		if opName == resetName {
-	// 			_, err = unboxedValue.Reset()
-	// 		} else if opName == cleanName {
-	// 			_, err = unboxedValue.Clean()
-	// 		} else {
-	// 			err = indexTerm.Errorf("iterators do not support command %q", opName)
-	// 		}
-	// 		v = err == nil
-	// 	}
 	case ExtIterator:
-		if indexTerm.symbol() == SymIdentifier {
+		if indexTerm.symbol() == SymVariable {
 			opName := indexTerm.source()
 			if unboxedValue.HasOperation(opName) {
 				v, err = unboxedValue.CallOperation(opName, []any{})