Method find_root_key

crates/kernel/src/equiv.rs:120–124

Find the root representative key for a given composite key. Returns None if the key is not in the union-find. Like `is_equiv`, takes the lookup key by reference so callers can reuse a single `EqKey` binding across multiple queries without cloning it for each call.

(&mut self, key: &EqKey)

    let rb = self.find(b);
    if ra == rb {
      return false;
    }
    if self.rank[ra] < self.rank[rb] {
      self.parent[ra] = rb;
    } else if self.rank[ra] > self.rank[rb] {
      self.parent[rb] = ra;
    } else {
      self.parent[rb] = ra;