Exposed sequence form to python

Author: StephenPasteris

src/games/gameseq.h

@@ -101,7 +101,7 @@ class MixedSequenceProfile {
     return probs[p_key];
   }
 
-  void GetMixedBehaviorProfile() const
+  MixedBehaviorProfile<T> GetMixedBehaviorProfile() const
   {
     MixedBehaviorProfile<T> mbp(game);
     for (const auto& [seq, prob] : probs) {
@@ -333,6 +333,8 @@ class GameSequenceForm {
 
   ~GameSequenceForm() = default;
 
+  GameSequence GetCorrespondingSequence(GameAction action) { return m_correspondence[action]; }
+
   const BehaviorSupportProfile &GetSupport() const { return m_support; }
 
   Sequences GetSequences() const { return {this}; }

src/pygambit/gambit.pyx

@@ -99,3 +99,4 @@ include "stratmixed.pxi"
 include "behavmixed.pxi"
 include "game.pxi"
 include "nash.pxi"
+include "sequence_form.pxi"

src/pygambit/sequence_form.pxi

@@ -0,0 +1,87 @@
+from libcpp.map cimport map as cpp_map
+from libcpp.memory cimport shared_ptr as cpp_shared_ptr
+from libcpp.vector cimport vector as cpp_vector
+
+@cython.cfunc
+def rat_to_py_new(r: c_Rational):
+    s = to_string(r).decode("ascii")
+    if not s:
+        return Rational(0)
+    return Rational(s)
+
+
+cdef extern from "../games/behavspt.h" namespace "Gambit":
+    cdef cppclass c_BehaviorSupportProfile "BehaviorSupportProfile":
+        c_BehaviourSupportProfile(const c_Game&) except +
+
+
+cdef extern from "../games/gameseq.h" namespace "Gambit":
+    cdef cppclass c_GameSequenceRep "GameSequenceRep":
+            pass
+
+
+ctypedef cpp_shared_ptr[c_GameSequenceRep] c_GameSequence
+
+
+cdef extern from "../games/gameseq.h" namespace "Gambit":
+    cdef cppclass c_PlayerSequences "GameSequenceForm::PlayerSequences":
+        cpp_vector[c_GameSequence].const_iterator begin()
+
+
+cdef extern from "../games/gameseq.h" namespace "Gambit":
+    cdef cppclass c_GameSequenceForm "GameSequenceForm":
+        c_GameSequenceForm(const c_BehaviorSupportProfile&) except +
+        c_Rational PayoffFromActions(cpp_map[c_GamePlayer, c_GameAction] action_profile, c_GamePlayer p_player)
+        c_GameSequence GetCorrespondingSequence(c_GameAction action)
+        c_PlayerSequences GetSequences(const c_GamePlayer &p_player) const
+        const c_Rational &GetPayoff(const cpp_map[c_GamePlayer, c_GameSequence] &p_profile, const c_GamePlayer &p_player) const
+        int GetConstraintEntry(const c_GameInfoset &p_infoset, const c_GameAction &p_action) const
+
+
+cdef class GameSequenceForm:
+    cdef c_GameSequenceForm* seq_form
+    cdef c_BehaviorSupportProfile* support
+
+    def __cinit__(self, py_game):
+        cdef Game game = cython.cast(Game, py_game)
+        cdef c_Game cpp_game = game.game
+        self.support = new c_BehaviorSupportProfile(cpp_game)
+        self.seq_form = new c_GameSequenceForm(deref(self.support))
+
+    def __dealloc__(self):
+        del self.seq_form
+        del self.support
+
+    def get_payoff(self, action_dict, py_player):
+        cdef Player player = cython.cast(Player, py_player)
+        cdef c_GamePlayer cpp_player = player.player
+        cdef cpp_map[c_GamePlayer, c_GameSequence] profile
+        cdef c_GamePlayer temp_player
+        cdef c_GameAction temp_action
+        cdef Player key
+        cdef Action value
+        for py_key, py_value in action_dict.items():
+            key = cython.cast(Player, py_key)
+            temp_player = key.player
+            if py_value is None:
+                profile[temp_player] = deref(self.seq_form.GetSequences(temp_player).begin())
+            else:
+                value = cython.cast(Action, py_value)
+                temp_action = value.action
+                profile[temp_player] = self.seq_form.GetCorrespondingSequence(temp_action)
+        cdef c_Rational payoff = self.seq_form.GetPayoff(profile, cpp_player)
+        return rat_to_py_new(payoff)
+
+    def get_constraint_entry(self, py_infoset, py_action):
+        cdef Infoset infoset = cython.cast(Infoset, py_infoset)
+        cdef c_GameInfoset cpp_infoset = infoset.infoset
+        cdef Action action
+        cdef c_GameAction cpp_action
+        if py_action is None:
+            cpp_action = <c_GameAction>0
+        else:
+            action = cython.cast(Action, py_action)
+            cpp_action = action.action
+        return self.seq_form.GetConstraintEntry(cpp_infoset, cpp_action)
+
+