Class FunctionResultSet

base/function_result_set.h:39–101

Represents a collection of unknown function results at a particular point in execution. Execution should advance further if this set of unknowns are provided. It may not advance if only a subset are provided. Set semantics use |IsEqualTo()| defined on |FunctionResult|.

// provided. It may not advance if only a subset are provided.
// Set semantics use |IsEqualTo()| defined on |FunctionResult|.
class FunctionResultSet final {
 private:
  using Container = absl::btree_set<FunctionResult>;

 public:
  using value_type = typename Container::value_type;
  using size_type = typename Container::size_type;
  using iterator = typename Container::const_iterator;
  using const_iterator = typename Container::const_iterator;

  FunctionResultSet() = default;
  FunctionResultSet(const FunctionResultSet&) = default;
  FunctionResultSet(FunctionResultSet&&) = default;
  FunctionResultSet& operator=(const FunctionResultSet&) = default;
  FunctionResultSet& operator=(FunctionResultSet&&) = default;

  // Merge constructor -- effectively union(lhs, rhs).
  FunctionResultSet(const FunctionResultSet& lhs, const FunctionResultSet& rhs);

  // Initialize with a single FunctionResult.
  explicit FunctionResultSet(FunctionResult initial)
      : function_results_{std::move(initial)} {}

  FunctionResultSet(std::initializer_list<FunctionResult> il)
      : function_results_(il) {}

  iterator begin() const { return function_results_.begin(); }

  const_iterator cbegin() const { return function_results_.cbegin(); }

  iterator end() const { return function_results_.end(); }

  const_iterator cend() const { return function_results_.cend(); }

  size_type size() const { return function_results_.size(); }

  bool empty() const { return function_results_.empty(); }

  bool operator==(const FunctionResultSet& other) const {
    return this == &other || function_results_ == other.function_results_;
  }

  bool operator!=(const FunctionResultSet& other) const {
    return !operator==(other);
  }

 private:
  friend class google::api::expr::runtime::AttributeUtility;
  friend class UnknownValue;
  friend class base_internal::UnknownSet;

  void Add(const FunctionResult& function_result) {
    function_results_.insert(function_result);
  }

  void Add(const FunctionResultSet& other) {
    for (const auto& function_result : other) {
      Add(function_result);