for i := 0; i < len(s); i++ {
		if s[i] > 127 {
			return nil, StructuralError{"IA5String contains invalid character"}
		}
	}

	return stringEncoder(s), nil
}

func makeNumericString(s string) (e encoder, err error) {
	for i := 0; i < len(s); i++ {
		if !isNumeric(s[i]) {
			return nil, StructuralError{"NumericString contains invalid character"}
		}
	}

	return stringEncoder(s), nil