Solving `Passport Application` with Haskell

> What are the base cases? A base case is an ancestor whose Britishness does not depend on a parent, e.g. someone who was naturalised, or born in the UK before 1983 (which makes one unconditionally british regardless of parents). That's right, further into the future we get from 1983, the taller these call-stacks can get.

This is insane to me, coming from a country that simply has a central database of all citizens and foreign residents, and a citizenship check is probably something like a single SELECT on an SQL table.

> citizenship check is probably something like a single SELECT on an SQL table

I am willing to bet, with extremely unfavorable odds to me, that is not true

Many countries simply have no way of knowing who their citizens are.

People born abroad are often citizens.

The British have had an insane number of changes in territory that affect citizenship.

Some of their current citizens have citizenship because they were born in Bombay (Mumbai). Others because they were born in Hong Kong.

Maintaining a reliable list of citizens requires regular registration, and loosing citizenship if you don’t register.

Even in that case it would probably enough to prove your citizenship once to get into the database.

SingPass[0] says hi.

[0] https://www.singpass.gov.sg/main/

It would have to be combine with other databases. A death index, at the least.