Do not apply nth style when the whole range is covered

src/tokenizer.go

@@ -18,6 +18,10 @@ type Range struct {
 	end   int
 }
 
+func (r Range) IsFull() bool {
+	return r.begin == rangeEllipsis && r.end == rangeEllipsis
+}
+
 func RangesToString(ranges []Range) string {
 	strs := []string{}
 	for _, r := range ranges {