fix inline index support, add string test case

main.go

@@ -233,7 +233,7 @@ func decodeConspackReader(r io.Reader) (interface{}, error) {
 			ty:    tmapType,
 		}, nil
 	} else if isIndex(header) {
-		if (header & 0x10) == 1 {
+		if (header & 0x10) > 0 {
 			// inline index
 			value := uint8(header & 0x0f)
 			return indexValue(value), nil
@@ -258,6 +258,8 @@ func main() {
 	lisp2048 := []byte{17, 8, 0}
 	wigglyDonkers := []byte{130, 64, 14, 87, 73, 71, 71, 76, 89, 45, 68, 79, 78, 75, 69, 82, 83, 129, 64, 10, 84, 82, 65, 67, 75, 69, 82, 78, 69, 84}
 	lispMap := []byte{48, 1, 64, 6, 119, 105, 103, 103, 108, 121, 64, 7, 100, 111, 110, 107, 101, 114, 115}
+	lispString := []byte{64, 14, 119, 105, 103, 103, 108, 121, 32, 100, 111, 110, 107, 101, 114, 115}
+
 	trackernetTrain := []byte{40, 3, 64, 9, 74, 45, 83, 70, 68, 45, 49, 55, 49, 56, 19, 177, 178, 64, 7, 49, 50, 49, 52, 52, 54, 50,
 		179, 64, 2, 56, 55, 180, 64, 3, 51, 53, 51, 181, 64, 2, 49, 49, 182, 17, 1, 237, 183, 64, 4, 56, 58,
 		48, 48, 184, 64, 20, 76, 101, 102, 116, 32, 78, 111, 114, 116, 104, 32, 71, 114, 101, 101, 110,
@@ -281,6 +283,8 @@ func main() {
 	log.Printf("%#v %#v", ok, err)
 	ok, err = decodeConspack(lispMap)
 	log.Printf("%#v %#v", ok, err)
+	ok, err = decodeConspack(lispString)
+	log.Printf("%#v %#v", ok, err)
 	ok, err = decodeConspack(trackernetTrain)
 	log.Printf("%#v %#v", ok, err)
 }