Predictive Parser (example) stmt→if.… while ..... begin.… f0Y.… 。 When we are trying to write the non-terminal stmt,if the current token is if we have to choose first production rule. When we are trying to write the non-terminal stmt,we can uniquely choose the production rule by just looking the current token. We eliminate the left recursion in the grammar,and left factor it.But it may not be suitable for predictive parsing(not LL(1)grammar). CS308 Compiler TheoryPredictive Parser (example) stmt → if ...... | while ...... | begin ...... | for ..... • When we are trying to write the non-terminal stmt, if the current token is if we have to choose first production rule. • When we are trying to write the non-terminal stmt, we can uniquely choose the production rule by just looking the current token. • We eliminate the left recursion in the grammar, and left factor it. But it t b it bl f di ti i ( t LL(1) ) CS308 Compiler Theory 5 may no t be suit able for predi ctive pars ing (no t LL(1) grammar )