Function BuildMatcher

src/PrefixMatch.cpp:302–327

}

std::unique_ptr<PrefixMatch::Tables::Matcher> BuildMatcher(
    const DictPtr& dict) {
  const std::list<DictPtr>* dictGroupItems = dict->GetDictGroupItems();
  if (dictGroupItems != nullptr) {
    // If the entire subtree is a pure union of leaf dicts, merge all entries
    // into a single LeafMatcher. One trie traversal finds the longest match
    // across all dicts, which equals union semantics, and eliminates the
    // overhead of GroupMatcher dispatch and multiple traversals.
    if (CanFlattenAsUnion(dict)) {
      std::unique_ptr<LeafMatcher> leaf(new LeafMatcher);
      CollectAllLeafDicts(dict, leaf.get());
      return std::move(leaf);
    }

    std::unique_ptr<GroupMatcher> group(
        new GroupMatcher(dict->GetMatchPolicy()));
    for (const DictPtr& child : *dictGroupItems) {
      group->AddChild(BuildMatcher(child));
    }
    return std::move(group);
  }

  std::unique_ptr<LeafMatcher> leaf(new LeafMatcher);
  leaf->AddDict(dict);
  return std::move(leaf);
}

PrefixMatch::PrefixMatch(const DictPtr& dict) {
  // Try to unwrap single dict group