func encodeUnicode(content string, ecl ErrorCorrectionLevel) (*utils.BitList, *versionInfo, error) {
data := []byte(content)
vi := findSmallestVersionInfo(ecl, byteMode, len(data)*8)
if vi == nil {
return nil, nil, errors.New("To much data to encode")
}
// It's not correct to add the unicode bytes to the result directly but most readers can't handle the
// required ECI header...
res := new(utils.BitList)
res.AddBits(int(byteMode), 4)
res.AddBits(len(content), vi.charCountBits(byteMode))
for _, b := range data {
res.AddByte(b)
}
addPaddingAndTerminator(res, vi)
return res, vi, nil
}
func encodeAlphaNumeric(content string, ecl ErrorCorrectionLevel) (*utils.BitList, *versionInfo, error) {
contentLenIsOdd := len(content)%2 == 1
contentBitCount := (len(content) / 2) * 11
if contentLenIsOdd {
contentBitCount += 6
}
vi := findSmallestVersionInfo(ecl, alphaNumericMode, contentBitCount)
if vi == nil {
return nil, nil, errors.New("To much data to encode")
}
res := new(utils.BitList)
res.AddBits(int(alphaNumericMode), 4)
res.AddBits(len(content), vi.charCountBits(alphaNumericMode))
encoder := stringToAlphaIdx(content)
for idx := 0; idx < len(content)/2; idx++ {
c1 := <-encoder
c2 := <-encoder
if c1 < 0 || c2 < 0 {
return nil, nil, fmt.Errorf("\"%s\" can not be encoded as %s", content, AlphaNumeric)
}
res.AddBits(c1*45+c2, 11)
}
if contentLenIsOdd {
c := <-encoder
if c < 0 {
return nil, nil, fmt.Errorf("\"%s\" can not be encoded as %s", content, AlphaNumeric)
}
res.AddBits(c, 6)
}
addPaddingAndTerminator(res, vi)
return res, vi, nil
}
func encodeNumeric(content string, ecl ErrorCorrectionLevel) (*utils.BitList, *versionInfo, error) {
contentBitCount := (len(content) / 3) * 10
switch len(content) % 3 {
case 1:
contentBitCount += 4
case 2:
contentBitCount += 7
}
vi := findSmallestVersionInfo(ecl, numericMode, contentBitCount)
if vi == nil {
return nil, nil, errors.New("To much data to encode")
}
res := new(utils.BitList)
res.AddBits(int(numericMode), 4)
res.AddBits(len(content), vi.charCountBits(numericMode))
for pos := 0; pos < len(content); pos += 3 {
var curStr string
if pos+3 <= len(content) {
curStr = content[pos : pos+3]
} else {
curStr = content[pos:]
}
i, err := strconv.Atoi(curStr)
if err != nil || i < 0 {
return nil, nil, fmt.Errorf("\"%s\" can not be encoded as %s", content, Numeric)
}
var bitCnt byte
switch len(curStr) % 3 {
case 0:
bitCnt = 10
case 1:
bitCnt = 4
break
case 2:
bitCnt = 7
break
}
res.AddBits(i, bitCnt)
}
addPaddingAndTerminator(res, vi)
return res, vi, nil
}