Fixed #30 : Add variable support in BNF concept definition

Fixed #31 : Add regex support in BNF Concept
Fixed #33 : Do not memorize object during restore

src/core/sheerka/ExecutionContext.py

@@ -199,6 +199,16 @@ class ExecutionContext:
             self._push = None
 
     def add_preprocess(self, name, **kwargs):
+        """
+        PreProcess item are used during the parsing and the evaluation of the ReturnValueConcept
+        Using them, you can twitch the behaviour of parser and evaluator (you can disable them for instance)
+        example :
+            context.add_preprocess(BaseEvaluator.get_name("priority15"), enabled=False)
+            context.add_preprocess(BaseEvaluator.get_name("all_priority15"), priority=99)
+        :param name:
+        :param kwargs:
+        :return:
+        """
         preprocess = self.sheerka.new(BuiltinConcepts.EVALUATOR_PRE_PROCESS)
         preprocess.set_value("preprocess_name", name)
         for k, v in kwargs.items():