Fixed one hot handling

MLP/src/MLP.cpp

@@ -152,7 +152,7 @@ dynet::Expression MLP::featValue2Expression(dynet::ComputationGraph & cg, const
   auto & ptr2index = lookupParameters[dict].second;
   auto & lu = lookupParameters[dict].first;
 
-  bool isConst = fv.policy == FeatureModel::Policy::Final;
+  bool isConst = (fv.policy == FeatureModel::Policy::Final) || (dict->mode == Dict::Mode::OneHot);
 
   auto it = ptr2index.find(fv.vec);
 

tape_machine/src/FeatureBank.cpp

@@ -139,6 +139,10 @@ FeatureModel::FeatureValue FeatureBank::getLength(Config & config, const Feature
   if(*fv.value == Dict::nullValueStr)
     return {dict, fv.name, &Dict::nullValueStr, dict->getNullValue(), policy};
 
+  int limit = 7;
+  if (len > limit)
+    len = limit;
+
   const std::string * str = dict->getStr(std::to_string(len));
 
   return {dict, fv.name, str, dict->getValue(*str), policy};