parsing - understanding grammar implementation in java -


i searching implementation of context free grammars in java operations on them related compilers design course ll(1), slr parsing , stuff , found implementation. grammar main method reading grammar file write grammar , code parse it, problem cannot write grammar in right way code understand, example cannot write epsilon transition whenever write epsilon or ε considered terminals. please me write grammar in right way code understand example grammar:

e  -> t e' e' -> + t e' | epsilon t  -> f t' t' -> * f t' | epsilon f  -> ( e ) | id

you make nonterminal empty string , have terminal produce empty string literal. e.g., empty -> '' , everywhere want empty string transition use empty.


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