line.go
func indent(str string) int {
	var i int

	for _, b := range str {
		if b != unicodeSpace {
			break
		}
		i++
	}

	return i / 2
}
func indent(str string) int {
	var i int

	for _, b := range str {
		if b != unicodeSpace {
			break
		}
		i++
	}

	return i / 2
}
// indent returns the line's indent.