Purpose of $default and $end

Hi, And I created a small program to test some small fundamentals and found that there is a lot of difference between the below 2 rules. sentence: /* empty */ | sentence line optional_comma '$'{ printf("\nInput line: >>>%s ::: %s <<<\n", $2, $3); } ; sentence: sentence

Re: Purpose of $default and $end

Small correction: The 2 rules are: sentence: /* empty */ | sentence line optional_comma '$'{ printf("\nInput line: >>>%s ::: %s <<<\n", $2, $3); } ; sentence: line optional_comma '$'{ printf("\nInput line: >>>%s ::: %s <<<\n", $2, $3); } ; On Sat, May 2, 2