Module Tp4::Relate

Maps a relation over the tuples in this tuple set, and get a new tuple predicate back representing the related values to the tuples in this set.

Sibling module of Map (which takes a “function” instead of a “relation”).

Note that this implicitly performs an intersection with the domain tuple set of the given relation.

Example:

predicate livesIn(Person p, City c) { c = p.getCity() }
Address hasMailingAddress(Person p, City c) { ... }

// Selects the mailing addresses that correspond to the people, city in `livesIn`.
select Tp2<Person, City, livesIn/2>::Relate<Address, hasMailingAddress/2>::find()

To preserve Person, City, see ExtendRelate.