Fix json parsing behavior (#83)

nnvm/include/dmlc/parameter.h

@@ -63,7 +63,9 @@ enum ParamInitOption {
   /*! \brief allow unknown parameters */
   kAllowUnknown,
   /*! \brief need to match exact parameters */
-  kAllMatch
+  kAllMatch,
+  /*! \brief allow unmatched hidden field with format __*__ */
+  kAllowHidden
 };
 }  // namespace parameter
 /*!
@@ -122,11 +124,11 @@ struct Parameter {
    */
   template<typename Container>
   inline void Init(const Container &kwargs,
-                   parameter::ParamInitOption option = parameter::kAllowUnknown) {
+                   parameter::ParamInitOption option = parameter::kAllowHidden) {
     PType::__MANAGER__()->RunInit(static_cast<PType*>(this),
                                   kwargs.begin(), kwargs.end(),
                                   NULL,
-                                  option == parameter::kAllowUnknown);
+                                  option);
   }
   /*!
    * \brief initialize the parameter by keyword arguments.
@@ -143,7 +145,7 @@ struct Parameter {
     std::vector<std::pair<std::string, std::string> > unknown;
     PType::__MANAGER__()->RunInit(static_cast<PType*>(this),
                                   kwargs.begin(), kwargs.end(),
-                                  &unknown, true);
+                                  &unknown, parameter::kAllowUnknown);
     return unknown;
   }
   /*!
@@ -369,7 +371,7 @@ class ParamManager {
                       RandomAccessIterator begin,
                       RandomAccessIterator end,
                       std::vector<std::pair<std::string, std::string> > *unknown_args,
-                      bool allow_unknown) const {
+                      parameter::ParamInitOption option) const {
     std::set<FieldAccessEntry*> selected_args;
     for (RandomAccessIterator it = begin; it != end; ++it) {
       FieldAccessEntry *e = Find(it->first);
@@ -381,7 +383,13 @@ class ParamManager {
         if (unknown_args != NULL) {
           unknown_args->push_back(*it);
         } else {
-          if (!allow_unknown) {
+          if (option != parameter::kAllowUnknown) {
+            if (option == parameter::kAllowHidden &&
+                it->first.length() > 4 &&
+                it->first.find("__") == 0 &&
+                it->first.rfind("__") == it->first.length()-2) {
+              continue;
+            }
             std::ostringstream os;
             os << "Cannot find argument \'" << it->first << "\', Possible Arguments:\n";
             os << "----------------\n";

nnvm/src/core/symbolic.cc

@@ -10,7 +10,7 @@
 namespace nnvm {
 
 namespace symbol_constants {
-const char *kNamespaceSeparator = "_";
+const char *kNamespaceSeparator = "$";
 }  // namespace symbol_constants
 
 // auxililary version attribute in variable.

nnvm/src/pass/saveload_json.cc

@@ -109,10 +109,6 @@ struct JSONNode {
     if (op_type_str != "null") {
       try {
         node->attrs.op = Op::Get(op_type_str);
-        // rebuild attribute parser
-        if (node->op()->attr_parser != nullptr) {
-          node->op()->attr_parser(&(node->attrs));
-        }
       } catch (const dmlc::Error &err) {
         std::ostringstream os;
         os << "Failed loading Op " << node->attrs.name
@@ -163,6 +159,10 @@ Graph LoadJSON(Graph src) {
       << "Load JSON require json to be presented.";
   const std::string &json_str =
       nnvm::get<std::string>(*src.attrs.at("json"));
+  bool no_parse = false;
+  if (src.attrs.count("load_json_no_parse")) {
+    no_parse = nnvm::get<bool>(*src.attrs.at("load_json_no_parse"));
+  }
   std::istringstream is(json_str);
   dmlc::JSONReader reader(&is);
   JSONGraph jgraph;
@@ -179,6 +179,11 @@ Graph LoadJSON(Graph src) {
     for (uint32_t nid : n.control_deps) {
       n.node->control_deps.push_back(jgraph.nodes[nid].node);
     }
+    // rebuild attribute parser
+    if (!no_parse && n.node->op() != nullptr &&
+        n.node->op()->attr_parser != nullptr) {
+      n.node->op()->attr_parser(&(n.node->attrs));
+    }
   }
   // consistent check
   for (uint32_t nid : jgraph.arg_nodes) {

nnvm/tests/python/test_symbol.py

@@ -12,7 +12,7 @@ def test_compose():
     assert y.list_attr()['gpu'] == '1'
     z = y.get_internals()
     assert z['add_output'].list_output_names() == ['add_output']
-    assert y.list_attr(recursive=True)['add_gpu'] == '2'
+    assert y.list_attr(recursive=True)['add$gpu'] == '2'
 
 def test_default_input():
     x = sym.Variable('x')