move indexOf into the vbantxt package.

improve the warning message on invalid bps value

cmd/vbantxt/main.go

@@ -82,12 +82,12 @@ func main() {
 	}
 }
 
-func createClient(host string, port int, streamname string, bps int, channel, ratelimit int) (*vbantxt.VbanTxt, error) {
+func createClient(host string, port int, streamname string, bps, channel, ratelimit int) (*vbantxt.VbanTxt, error) {
 	client, err := vbantxt.New(
 		host,
 		port,
 		streamname,
-		vbantxt.WithBPSOpt(indexOf(vbantxt.BpsOpts, bps)),
+		vbantxt.WithBPSOpt(bps),
 		vbantxt.WithChannel(channel),
 		vbantxt.WithRateLimit(time.Duration(ratelimit)*time.Millisecond))
 	if err != nil {

cmd/vbantxt/util.go

@@ -15,12 +15,3 @@ func flagsPassed(flags []string) bool {
 	})
 	return found
 }
-
-func indexOf[T comparable](collection []T, e T) int {
-	for i, x := range collection {
-		if x == e {
-			return i
-		}
-	}
-	return -1
-}

option.go

@@ -17,10 +17,11 @@ func WithRateLimit(ratelimit time.Duration) Option {
 }
 
 // WithBPSOpt is a functional option to set the bps index for {VbanTx}.{Packet}.bpsIndex
-func WithBPSOpt(bpsIndex int) Option {
+func WithBPSOpt(bps int) Option {
 	return func(vt *VbanTxt) {
-		if bpsIndex < 0 || bpsIndex >= len(BpsOpts) {
+		bpsIndex := indexOf(BpsOpts, bps)
-			log.Warnf("invalid bpsIndex %d, defaulting to 0", bpsIndex)
+		if bpsIndex == -1 {
+			log.Warnf("invalid bps value %d, expected one of %v, defaulting to 0", bps, BpsOpts)
 			return
 		}
 		vt.packet.bpsIndex = bpsIndex

util.go

@@ -0,0 +1,10 @@
+package vbantxt
+
+func indexOf[T comparable](collection []T, e T) int {
+	for i, x := range collection {
+		if x == e {
+			return i
+		}
+	}
+	return -1
+}