Function tor_config::load::intersect_unrecognized_lists

fn intersect_unrecognized_lists(
    al: BTreeSet<DisfavouredKey>,
    bl: BTreeSet<DisfavouredKey>
) -> BTreeSet<DisfavouredKey>

Computes the intersection, resolving ignorances at different depths

Eg if a contains application.wombat and b contains application, we need to return application.wombat.

Formally

A configuration key (henceforth “key”) is a sequence of PathEntry, interpreted as denoting a place in a tree-like hierarchy.

Each input BTreeSet denotes a subset of the configuration key space. Any key in the set denotes itself, but also all possible keys which have it as a prefix. We say a s set is “minimal” if it doesn’t have entries made redundant by this rule.

This function computes a minimal intersection of two minimal inputs. If the inputs are not minimal, the output may not be either (although serde_ignored gives us minimal sets, so that case is not important).