onioncollab/src/util/partial_ordering.ts

export function visitPartialOrdering<T>(elements: T[], smallerThan: (T) => T[], visitCallback: (T) => void) {
  const visitable = new Set(elements);
  const remaining = new Set(elements);
  while (remaining.size > 0) {
    let found = false;
    for (const elem of remaining) {
      if (smallerThan(elem).every(e => !visitable.has(e) || !remaining.has(e))) {
        visitCallback(elem);
        remaining.delete(elem);
        found = true;
        break;
      }
    }
    if (!found) {
      throw new Error("Could not find a smallest element - not a partial ordering?");
    }
  }
}