61 lines
1.1 KiB
Go
61 lines
1.1 KiB
Go
package utf8s
|
|
|
|
import (
|
|
"io"
|
|
)
|
|
|
|
// WriteRune writes a single UTF-8 encoded Unicode character and returns the number of bytes written.
|
|
func WriteRune(writer io.Writer, r rune) (int, error) {
|
|
if nil == writer {
|
|
return 0, errNilWriter
|
|
}
|
|
|
|
switch {
|
|
case 127 >= r:
|
|
var buffer [1]byte
|
|
|
|
buffer[0] = byte(r)
|
|
|
|
p := buffer[:]
|
|
|
|
return writer.Write(p)
|
|
|
|
case 0x7FF >= r:
|
|
var buffer [2]byte
|
|
|
|
buffer[0] = 0xC0 | byte((0x000007C0 & r) >> 6)
|
|
buffer[1] = 0x80 | byte( 0x0000003F & r)
|
|
|
|
p := buffer[:]
|
|
|
|
return writer.Write(p)
|
|
|
|
case 0xFFFF >= r:
|
|
var buffer [3]byte
|
|
|
|
buffer[0] = 0xE0 | byte((0x0000F000 & r) >> 12)
|
|
buffer[1] = 0x80 | byte((0x00000FC0 & r) >> 6)
|
|
buffer[2] = 0x80 | byte( 0x0000003F & r)
|
|
|
|
p := buffer[:]
|
|
|
|
return writer.Write(p)
|
|
|
|
case 0x10FFFF >= r:
|
|
var buffer [4]byte
|
|
|
|
buffer[0] = 0xF0 | byte((0x001C0000 & r) >> 18)
|
|
buffer[1] = 0x80 | byte((0x0003F000 & r) >> 12)
|
|
buffer[2] = 0x80 | byte((0x00000FC0 & r) >> 6)
|
|
buffer[3] = 0x80 | byte( 0x0000003F & r)
|
|
|
|
p := buffer[:]
|
|
|
|
return writer.Write(p)
|
|
|
|
default:
|
|
return 0, errInternalError
|
|
}
|
|
|
|
}
|