split limit determination into separate function

main.go

@@ -34,17 +34,23 @@ func formula(p float64) int64 {
 	return int64(yearsAgo * 31556926)
 }
 
-func (db *TimelineDB) closestEvents(t int64, n int, after bool, before bool) ([]EventsRow, error) {
-	ulimit := int64(math.MaxInt64)
+func limits(t int64, after bool, before bool) (int64, int64, error) {
 	llimit := int64(math.MinInt64)
+	ulimit := int64(math.MaxInt64)
+	var err error
+
 	if after && before {
-		return nil, errors.New("after and before can't both be true")
+		err = errors.New("after and before can't both be true")
 	} else if after {
 		llimit = t
 	} else if before {
 		ulimit = t
 	}
 
+	return llimit, ulimit, err
+}
+
+func (db *TimelineDB) closestEvents(t int64, n int, llimit int64, ulimit int64) ([]EventsRow, error) {
 	query := `
 	select description, timestamp, yearknown, monthknown, dayknown, hourknown, minuteknown, secondknown
 	from events
@@ -130,7 +136,12 @@ func main() {
 	}
 	defer db.Close()
 
-	events, err := db.closestEvents(t, *nevents, *after, *before)
+	llimit, ulimit, err := limits(t, *after, *before)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	events, err := db.closestEvents(t, *nevents, llimit, ulimit)
 	if err != nil {
 		log.Fatal(err)
 	}