Expressions

- Implemented sequence --> infix converter.
- Added new Lexer code.
- Added Lexer unit tests.

src/Expression.h

@@ -38,13 +38,24 @@ public:
   Expression (Arguments&);
   ~Expression ();
   bool eval (Task&);
-  void toInfix ();
-  void toPostfix ();
 
+private:
+  void expand_sequence ();
+  void expand_expression ();
+  void expand_tag (const std::string&);
+  void expand_attr (const std::string&);
+  void expand_attmod (const std::string&);
+  void expand_word (const std::string&);
+  void expand_pattern (const std::string&);
+
+  void to_infix ();
+  void to_postfix ();
+  bool is_new_style ();
   void dump (const std::string&);
 
 private:
   Arguments _original;
+  Arguments _sequenced;
   Arguments _infix;
   Arguments _postfix;
 };