All functionalities ready.

Todo: add all the fermion action modules

lib/serialisation/BaseIO.h

@@ -105,7 +105,7 @@ namespace Grid {
   public:
     Reader(void);
     virtual ~Reader(void) = default;
-    void push(const std::string &s);
+    bool push(const std::string &s);
     void pop(void);
     template <typename U>
     typename std::enable_if<std::is_base_of<Serializable, U>::value, void>::type
@@ -160,15 +160,15 @@ namespace Grid {
   
   // Generic reader interface
   template <typename T>
-  inline void push(Reader<T> &r, const std::string &s)
+  inline bool push(Reader<T> &r, const std::string &s)
   {
-    r.push(s);
+    return r.push(s);
   }
   
   template <typename T>
-  inline void push(Reader<T> &r, const char *s)
+  inline bool push(Reader<T> &r, const char *s)
   {
-    r.push(std::string(s));
+    return r.push(std::string(s));
   }
   
   template <typename T>
@@ -236,9 +236,9 @@ namespace Grid {
   }
   
   template <typename T>
-  void Reader<T>::push(const std::string &s)
+  bool Reader<T>::push(const std::string &s)
   {
-    upcast->push(s);
+    return upcast->push(s);
   }
   
   template <typename T>

lib/serialisation/BinaryIO.h

@@ -60,7 +60,7 @@ namespace Grid {
   public:
     BinaryReader(const std::string &fileName);
     virtual ~BinaryReader(void) = default;
-    void push(const std::string &s) {};
+    bool push(const std::string &s) {return true;}
     void pop(void) {};
     template <typename U>
     void readDefault(const std::string &s, U &output);

lib/serialisation/TextIO.cc

@@ -68,9 +68,10 @@ TextReader::TextReader(const string &fileName)
     } 
 }
 
-void TextReader::push(const string &s)
+bool TextReader::push(const string &s)
 {
   level_++;
+  return true;
 };
 
 void TextReader::pop(void)

lib/serialisation/TextIO.h

@@ -63,7 +63,7 @@ namespace Grid
   public:
     TextReader(const std::string &fileName);
     virtual ~TextReader(void) = default;
-    void push(const std::string &s);
+    bool push(const std::string &s);
     void pop(void);
     template <typename U>
     void readDefault(const std::string &s, U &output);

lib/serialisation/XmlIO.cc

@@ -70,10 +70,13 @@ XmlReader::XmlReader(const string &fileName)
   node_ = doc_.child("grid");
 }
 
-void XmlReader::push(const string &s)
+bool XmlReader::push(const string &s)
 {
   node_ = node_.child(s.c_str());
-  // add error check
+  if (node_ == NULL)
+    return false;
+
+  return true;
 }
 
 void XmlReader::pop(void)

lib/serialisation/XmlIO.h

@@ -66,7 +66,7 @@ namespace Grid
   public:
     XmlReader(const std::string &fileName);
     virtual ~XmlReader(void) = default;
-    void push(const std::string &s);
+    bool push(const std::string &s);
     void pop(void);
     bool nextElement(const std::string &s);
     template <typename U>