say .parse: $*IN.slurp given grammar { rule TOP { <identifier> <identifier> '=' <expression> } token ws { [ <comment> | \s+ ]* <!ww> } token comment { '#[' <-[\]]>* ']' } token identifier { \w+ } rule expression { '(' <expression> ')' | <number> | <string> | ... } token number { \d+ } token string { '"' <-["]>* '"' } }