What do you mean by LR Parser

Question

What do you mean by LR Parser? Describe its parts with appropriate description.

Answer 1

The LR means Left-to-Right signifying the parser that reads the input string from left to right. LR parser can be written for almost all the Programming constructs. LR parser comprises of two parts: Driver Routine and Parsing Table.

a) The Driver routine is similar for all the Parsers only the Parsing Table changes.

b) The Parsing Table is basically a form of representing the State-Transition Diagram for the language. It includes the entries for all possible States and the input symbols. In each state there in a predetermined next state based on the input symbol. Whenever there is any duplicate entry or two next states for the similar symbol, then there is an ambiguity in grammar.