go-utf8/len.go

package utf8s

// Len returns the number of bytes in a UTF-8 encoding of this Unicode code point.
func Len(r rune) int {

	switch {
	case 127 >= r:
		return 1

	case 0x7FF >= r:
		return 2

	case 0xFFFF >= r:
		return 3

	case 0x10FFFF >= r:
		return 4

	default:
		return 0
	}
}