Define Disadvantages of Top Down parsing of Backtracking
The disadvantages of top down parsing of backtracking:
(i) Semantic actions cannot be carried out while making a prediction. The actions should be delayed until the prediction is known to be a part of a successful parse.
(ii) Precise error reporting is not probable. A mismatch just triggers backtracking. A source string is identified to be erroneous just only after all predictions have failed.