A personnummer is a social security number in Sweden. This is early development of parsing such numbers in ReScript.
type t = {
year: string,
month: string,
day: string,
gender: Gender.t,
placeOfBirth: PlaceOfBirth.t,
}
type t = Valid(t) | Invalid
Personnummer.Parse.make("1212121212")
// Valid({
// year: "12",
// month: "12",
// day: "12",
// gender: Male,
// placeOfBirth: Stockholm,
//})