Fixed #48 : RelationalExpressionParser: Implement relational operator parser

Fixed #49 : ExpressionParser: Implement ExpressionParser
Fixed #50 : Implement ReteConditionExprVisitor
Fixed #51 : Implement PythonConditionExprVisitor
Fixed #52 : SheerkaConceptManager: I can get and set concept property

src/core/sheerka/Sheerka.py

@@ -113,6 +113,7 @@ class Sheerka(Concept):
             "test_using_context": SheerkaMethod(self.test_using_context, False),
             "test_dict": SheerkaMethod(self.test_dict, False),
             "test_error": SheerkaMethod(self.test_error, False),
+            "is_sheerka": SheerkaMethod(self.is_sheerka, False),
         }
 
         self.concepts_ids = None
@@ -767,6 +768,16 @@ class Sheerka(Concept):
 
         return a.key in b
 
+    def is_sheerka(self, obj):
+        if isinstance(obj, Concept) and obj.id == self.id:
+            return True
+
+        from evaluators.PythonEvaluator import Expando
+        if isinstance(obj, Expando) and obj.get_name() == "sheerka":
+            return True
+
+        return False
+
     @staticmethod
     def get_unknown(metadata):
         """