grammars/grammar_pithy.js
function commaList(r, trailing = true) {
            var result = r.then(guardedSeq(_this.comma, r).zeroOrMore);
            if (trailing) return result.then(_this.comma.opt);
            else return result;
        }
function commaList(r, trailing = true) {
            var result = r.then(guardedSeq(_this.comma, r).zeroOrMore);
            if (trailing) return result.then(_this.comma.opt);
            else return result;
        }
function commaList ( r , trailing = true ) { var result = r . then ( guardedSeq ( _this . comma , r ) . zeroOrMore ) ; if ( trailing ) return result . then ( _this . comma . opt ) ; else return result ; }
Comma delimited list with a trailing comma
Comma delimited list with a trailing comma