Changed name of optimizer checkpoints to avoid confusion with models checkpoints

reading_machine/src/ReadingMachine.cpp

@@ -30,7 +30,16 @@ ReadingMachine::ReadingMachine(std::filesystem::path path, std::vector<std::file
   classifier->getNN()->registerEmbeddings(maxDictSize);
   classifier->getNN()->to(NeuralNetworkImpl::device);
 
-  torch::load(classifier->getNN(), models[0]);
+  if (models.size() > 1)
+    util::myThrow("having more than one model file is not supported");
+
+  try
+  {
+    torch::load(classifier->getNN(), models[0]);
+  } catch (std::exception & e)
+  {
+    util::myThrow(fmt::format("error when loading '{}' : {}", models[0].string(), e.what()));
+  }
 }
 
 void ReadingMachine::readFromFile(std::filesystem::path path)

trainer/src/MacaonTrain.cpp

@@ -168,7 +168,7 @@ int MacaonTrain::main()
     trainer.createDevDataset(devGoldConfig, debug, modelPath/"examples/dev", currentEpoch, dynamicOracleInterval);
 
   machine.getClassifier()->resetOptimizer();
-  auto optimizerCheckpoint = machinePath.parent_path() / "optimizer.pt";
+  auto optimizerCheckpoint = machinePath.parent_path() / "checkpoint.optimizer";
   if (std::filesystem::exists(trainInfos))
     machine.getClassifier()->loadOptimizer(optimizerCheckpoint);