numberの括りだし

roman.go

package roman

type Arabian uint16

var numbers = []struct {
	arabian Arabian
	roman   string
}{
	{5, "V"},
	{1, "I"},
}

func (in Arabian) ToRoman() (out string) {
	for remain := in; remain != 0; {
		for _, n := range numbers {
			if remain >= n.arabian {
				out += n.roman
				remain = remain - n.arabian
			}
		}
	}
	return
}