rename

sentence.go

@@ -110,16 +110,16 @@ func (p *SentenceParser) parseBaseSentence(raw string) (BaseSentence, error) {
 	if raw == "" {
 		return BaseSentence{}, errors.New("nmea: can not parse empty input")
 	}
-	tagBlock, sentenceStartIndex, err := ParseTagBlock(raw)
+	tagBlock, tagBlockLen, err := ParseTagBlock(raw)
 	if err != nil {
 		return BaseSentence{}, err
 	}
-	if sentenceStartIndex > 0 && p.OnTagBlock != nil {
+	if tagBlockLen > 0 && p.OnTagBlock != nil {
 		if err := p.OnTagBlock(tagBlock); err != nil {
 			return BaseSentence{}, err
 		}
 	}
-	raw = raw[sentenceStartIndex:]
+	raw = raw[tagBlockLen:]
 
 	startIndex := strings.IndexAny(raw, SentenceStart+SentenceStartEncapsulated)
 	if startIndex != 0 {

tagblock.go

@@ -18,7 +18,7 @@ type TagBlock struct {
 }
 
 // ParseTagBlock parses tag blocks from a sentence string.
-// The second return value is the index where the sentence starts.
+// The second return value is the length of the tag block prefix.
 // See: https://gpsd.gitlab.io/gpsd/AIVDM.html#_nmea_tag_blocks
 func ParseTagBlock(raw string) (TagBlock, int, error) {
 	startOfTagBlock := strings.IndexByte(raw, TagBlockSep)

tagblock_test.go

@@ -1,6 +1,8 @@
 package nmea
 
 import (
+	"log"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -11,7 +13,7 @@ var tagblocktests = []struct {
 	raw   string
 	err   string
 	block TagBlock
-	index int
+	len   int
 }{
 	{
 
@@ -21,7 +23,7 @@ var tagblocktests = []struct {
 			Time:   1553390539,
 			Source: "Satelite_1",
 		},
-		index: 30,
+		len: 30,
 	},
 	{
 
@@ -31,7 +33,7 @@ var tagblocktests = []struct {
 			Time:   1564827317,
 			Source: "satelite",
 		},
-		index: 28,
+		len: 28,
 	},
 	{
 
@@ -41,7 +43,7 @@ var tagblocktests = []struct {
 			Time:   1564827317,
 			Source: "",
 		},
-		index: 28,
+		len: 28,
 	},
 	{
 		name: "Test unix timestamp",
@@ -50,7 +52,7 @@ var tagblocktests = []struct {
 			Time:   1564827317,
 			Source: "",
 		},
-		index: 28,
+		len: 28,
 	},
 	{
 
@@ -60,7 +62,7 @@ var tagblocktests = []struct {
 			Time:   1564827317000,
 			Source: "",
 		},
-		index: 31,
+		len: 31,
 	},
 	{
 
@@ -75,7 +77,7 @@ var tagblocktests = []struct {
 			Text:         "helloworld",
 			LineCount:    13,
 		},
-		index: 72,
+		len: 72,
 	},
 	{
 
@@ -122,14 +124,14 @@ var tagblocktests = []struct {
 func TestParseTagBlock(t *testing.T) {
 	for _, tt := range tagblocktests {
 		t.Run(tt.name, func(t *testing.T) {
-			b, index, err := ParseTagBlock(tt.raw)
+			b, n, err := ParseTagBlock(tt.raw)
 			if tt.err != "" {
 				assert.Error(t, err)
 			} else {
 				assert.NoError(t, err)
 			}
 			assert.Equal(t, tt.block, b)
-			assert.Equal(t, tt.index, index)
+			assert.Equal(t, tt.len, n)
 		})
 	}
 }