forkjo/modules/mahonia/gbk.go
2014-09-07 19:58:01 -04:00

78 lines
1.1 KiB
Go

package mahonia
// Converters for GBK encoding.
func init() {
RegisterCharset(&Charset{
Name: "GBK",
Aliases: []string{"GB2312"}, // GBK is a superset of GB2312.
NewDecoder: func() Decoder {
return decodeGBKRune
},
NewEncoder: func() Encoder {
return encodeGBKRune
},
})
}
func decodeGBKRune(p []byte) (r rune, size int, status Status) {
if len(p) == 0 {
status = NO_ROOM
return
}
b := p[0]
if b < 128 {
return rune(b), 1, SUCCESS
}
if len(p) < 2 {
status = NO_ROOM
return
}
c := uint16(p[0])<<8 + uint16(p[1])
r = rune(gbkToUnicode[c])
if r == 0 {
r = gbkToUnicodeExtra[c]
}
if r != 0 {
return r, 2, SUCCESS
}
return 0xfffd, 1, INVALID_CHAR
}
func encodeGBKRune(p []byte, r rune) (size int, status Status) {
if len(p) == 0 {
status = NO_ROOM
return
}
if r < 128 {
p[0] = byte(r)
return 1, SUCCESS
}
if len(p) < 2 {
status = NO_ROOM
return
}
var c uint16
if r < 0x10000 {
c = unicodeToGBK[r]
} else {
c = unicodeToGBKExtra[r]
}
if c != 0 {
p[0] = byte(c >> 8)
p[1] = byte(c)
return 2, SUCCESS
}
p[0] = 0x1a
return 1, INVALID_CHAR
}