Started implementation of BeamSearch

decoder/src/Decoder.cpp

@@ -152,6 +152,19 @@ void applyActionAndTakeTransition(TransitionMachine & tm, Action * action, Confi
     tm.takeTransition(transition);
 }
 
+struct BeamNode
+{
+  Classifier::WeightedActions weightedActions;
+  double totalEntropy;
+  TransitionMachine tm;
+  Config config;
+
+  BeamNode(TransitionMachine & tm, Config & config) : tm(tm), config(config)
+  {
+    totalEntropy = 0.0;
+  }
+};
+
 void Decoder::decode()
 {
   float entropyAccumulator = 0.0;
@@ -164,8 +177,23 @@ void Decoder::decode()
   float currentSpeed = 0.0;
   auto pastTime = std::chrono::high_resolution_clock::now();
 
-  while (!config.isFinal())
+  std::vector< std::shared_ptr<BeamNode> > beam;
+  beam.emplace_back(new BeamNode(tm, config));
+
+  auto sortBeam = [&beam]()
   {
+    std::sort(beam.begin(), beam.end(), [](std::shared_ptr<BeamNode> a, std::shared_ptr<BeamNode> b)
+        {
+          return a->totalEntropy < b->totalEntropy;
+        });
+  };
+
+  while (!beam[0]->config.isFinal())
+  {
+    for (auto & node : beam)
+    {
+    auto & tm = node->tm;
+    auto & config = node->config;
     TransitionMachine::State * currentState = tm.getCurrentState();
     Classifier * classifier = currentState->classifier;
     config.setCurrentStateName(&currentState->name);
@@ -191,11 +219,12 @@ void Decoder::decode()
     computeAndRecordEntropy(config, weightedActions, entropyAccumulator);
     computeAndPrintSequenceEntropy(config, justFlipped, errors, entropyAccumulator, nbActionsInSequence);
     }
+  }
 
   if (ProgramParameters::errorAnalysis)
     errors.printStats();
   else
-    config.printAsOutput(stdout);
+    beam[0]->config.printAsOutput(stdout);
 
   fprintf(stderr, "                                                     \n");
 }

transition_machine/include/Classifier.hpp

@@ -46,12 +46,12 @@ class Classifier
   /// In train mode, the underlying neural network's parameters will be zero-initialized, instead of being read from a file.
   bool trainMode;
   /// @brief The FeatureModel of this Classifier.
-  std::unique_ptr<FeatureModel> fm;
+  std::shared_ptr<FeatureModel> fm;
   /// @brief The ActionSet of this Classifier.
-  std::unique_ptr<ActionSet> as;
+  std::shared_ptr<ActionSet> as;
   /// @brief The neural network used by this Classifier.
   /// The neural network is only used for Classifier of type Prediction.
-  std::unique_ptr<NeuralNetwork> nn;
+  std::shared_ptr<NeuralNetwork> nn;
   /// @brief A string describing the topology of the underlying neural network.
   std::string topology;
   /// @brief The oracle being used by this Classifier.

transition_machine/include/TransitionMachine.hpp

@@ -60,9 +60,9 @@ class TransitionMachine
   /// @brief Whether or not the program is in train mode.
   bool trainMode;
   /// @brief Store the Classifier by their name.
-  std::map< std::string, std::unique_ptr<Classifier> > str2classifier;
+  std::map< std::string, std::shared_ptr<Classifier> > str2classifier;
   /// @brief Store the State by their name.
-  std::map< std::string, std::unique_ptr<State> > str2state;
+  std::map< std::string, std::shared_ptr<State> > str2state;
   /// @brief Pointer to the initial State.
   State * initialState;
   /// @brief Pointer to the current State.