%start List
%title "A simple comma separated list of integers"
%comment "A trailing comma is allowed."

%%

/* 0 */ List: ListOpt /* Option */;
/* 1 */ ListOpt /* `Option<T>::Some` */: Num ListRest ListOpt0 /* Option */;
/* 2 */ ListOpt0 /* `Option<T>::Some` */: ",";
/* 3 */ ListOpt0 /* `Option<T>::None` */: ;
/* 4 */ ListOpt /* `Option<T>::None` */: ;
/* 5 */ ListRest: ListRestOpt /* Option */;
/* 6 */ ListRestOpt /* `Option<T>::Some` */: "," Num ListRest;
/* 7 */ ListRestOpt /* `Option<T>::None` */: ;
/* 8 */ Num: "0|[1-9][0-9]*";