InfostateTree python bind

.gitignore

@@ -36,6 +36,7 @@ open_spiel/games/universal_poker/double_dummy_solver/
 open_spiel/games/hanabi/hanabi-learning-environment/
 /open_spiel/pybind11_abseil/
 pybind11/
+!open_spiel/python/pybind11
 
 # Install artifacts
 download_cache/

open_spiel/algorithms/infostate_tree.cc

@@ -200,15 +200,15 @@ void InfostateTree::CollectNodesAtDepth(InfostateNode* node, size_t depth) {
     CollectNodesAtDepth(child, depth + 1);
 }
 
-std::ostream& InfostateTree::operator<<(std::ostream& os) const {
-  return os << "Infostate tree for player " << acting_player_ << ".\n"
-            << "Tree height: " << tree_height_ << '\n'
-            << "Root branching: " << root_branching_factor() << '\n'
-            << "Number of decision infostate nodes: " << num_decisions() << '\n'
-            << "Number of sequences: " << num_sequences() << '\n'
-            << "Number of leaves: " << num_leaves() << '\n'
+std::ostream& operator<<(std::ostream& os, const InfostateTree& tree) {
+  return os << "Infostate tree for player " << tree.acting_player_ << ".\n"
+            << "Tree height: " << tree.tree_height_ << '\n'
+            << "Root branching: " << tree.root_branching_factor() << '\n'
+            << "Number of decision infostate nodes: " << tree.num_decisions() << '\n'
+            << "Number of sequences: " << tree.num_sequences() << '\n'
+            << "Number of leaves: " << tree.num_leaves() << '\n'
             << "Tree certificate: " << '\n'
-            << root().MakeCertificate() << '\n';
+            << tree.root().MakeCertificate() << '\n';
 }
 
 std::unique_ptr<InfostateNode> InfostateTree::MakeNode(
@@ -485,7 +485,8 @@ absl::optional<DecisionId> InfostateTree::DecisionIdForSequence(
   }
 }
 absl::optional<InfostateNode*> InfostateTree::DecisionForSequence(
-    const SequenceId& sequence_id) {
+    const SequenceId& sequence_id) const
+{
   SPIEL_DCHECK_TRUE(sequence_id.BelongsToTree(this));
   InfostateNode* node = sequences_.at(sequence_id.id());
   SPIEL_DCHECK_TRUE(node);
@@ -595,7 +596,7 @@ std::pair<size_t, size_t> InfostateTree::CollectStartEndSequenceIds(
 }
 
 std::pair<double, SfStrategy> InfostateTree::BestResponse(
-    TreeplexVector<double>&& gradient) const {
+    TreeplexVector<double> gradient) const {
   SPIEL_CHECK_EQ(this, gradient.tree());
   SPIEL_CHECK_EQ(num_sequences(), gradient.size());
   SfStrategy response(this);
@@ -647,7 +648,7 @@ std::pair<double, SfStrategy> InfostateTree::BestResponse(
   return {gradient[empty_sequence()], response};
 }
 
-double InfostateTree::BestResponseValue(LeafVector<double>&& gradient) const {
+double InfostateTree::BestResponseValue(LeafVector<double> gradient) const {
   // Loop over all heights.
   for (int d = tree_height_ - 1; d >= 0; d--) {
     int left_offset = 0;

open_spiel/algorithms/infostate_tree.h

@@ -237,6 +237,9 @@ class RangeIterator {
   bool operator!=(const RangeIterator& other) const {
     return id_ != other.id_ || tree_ != other.tree_;
   }
+  bool operator==(const RangeIterator& other) const {
+    return !(this->operator!=(other));
+  }
   Id operator*() { return Id(id_, tree_); }
 };
 template <class Id>
@@ -285,7 +288,7 @@ std::shared_ptr<InfostateTree> MakeInfostateTree(
     const std::vector<InfostateNode*>& start_nodes,
     int max_move_ahead_limit = 1000);
 
-class InfostateTree final {
+class InfostateTree final : public std::enable_shared_from_this<InfostateTree> {
   // Note that only MakeInfostateTree is allowed to call the constructor
   // to ensure the trees are always allocated on heap. We do this so that all
   // the collected pointers are valid throughout the tree's lifetime even if
@@ -305,6 +308,10 @@ class InfostateTree final {
       const std::vector<const InfostateNode*>&, int);
 
  public:
+  // -- gain shared ownership of the allocated infostate object
+  std::shared_ptr< InfostateTree > shared_ptr() { return shared_from_this(); }
+  std::shared_ptr< const InfostateTree > shared_ptr() const { return shared_from_this(); }
+
   // -- Root accessors ---------------------------------------------------------
   const InfostateNode& root() const { return *root_; }
   InfostateNode* mutable_root() { return root_.get(); }
@@ -344,7 +351,7 @@ class InfostateTree final {
   // Returns `None` if the sequence is the empty sequence.
   absl::optional<DecisionId> DecisionIdForSequence(const SequenceId&) const;
   // Returns `None` if the sequence is the empty sequence.
-  absl::optional<InfostateNode*> DecisionForSequence(const SequenceId&);
+  absl::optional<InfostateNode*> DecisionForSequence(const SequenceId& sequence_id) const;
   // Returns whether the sequence ends with the last action the player can make.
   bool IsLeafSequence(const SequenceId&) const;
 
@@ -385,13 +392,13 @@ class InfostateTree final {
   // Compute best response and value based on gradient from opponents.
   // This consumes the gradient vector, as it is used to compute the value.
   std::pair<double, SfStrategy> BestResponse(
-      TreeplexVector<double>&& gradient) const;
+      TreeplexVector<double> gradient) const;
   // Compute best response value based on gradient from opponents over leaves.
   // This consumes the gradient vector, as it is used to compute the value.
-  double BestResponseValue(LeafVector<double>&& gradient) const;
+  double BestResponseValue(LeafVector<double> gradient) const;
 
   // -- For debugging ----------------------------------------------------------
-  std::ostream& operator<<(std::ostream& os) const;
+  friend std::ostream& operator<<(std::ostream& os, const InfostateTree& tree);
 
  private:
   const Player acting_player_;
@@ -550,6 +557,7 @@ class InfostateNode final {
   const InfostateNodeType& type() const { return type_; }
   size_t depth() const { return depth_; }
   bool is_root_node() const { return !parent_; }
+  bool is_filler_node() const { return infostate_string_ == kFillerInfostate; }
   bool has_infostate_string() const {
     return infostate_string_ != kFillerInfostate &&
            infostate_string_ != kDummyRootNodeInfostate;

open_spiel/python/CMakeLists.txt

@@ -77,6 +77,9 @@ endif()
 # List of all Python bindings to add to pyspiel.
 include_directories (../pybind11_abseil ../../pybind11/include)
 set(PYTHON_BINDINGS ${PYTHON_BINDINGS}
+  pybind11/algorithms_infostate_tree.cc
+  pybind11/algorithms_infostate_tree.tcc
+  pybind11/algorithms_infostate_tree.h
   pybind11/algorithms_corr_dist.cc
   pybind11/algorithms_corr_dist.h
   pybind11/algorithms_trajectories.cc