Fixed #29: Parsers: Implement parsing memoization

Fixed #77 : Parser: ShortTermMemoryParser should be called separately
Fixed #78 : Remove VariableNode usage
Fixed #79 : ConceptManager: Implement compile caching
Fixed #80 : SheerkaExecute : parsers_key is not correctly computed
Fixed #81 : ValidateConceptEvaluator : Validate concept's where and pre clauses right after the parsing
Fixed #82 : SheerkaIsAManager: isa() failed when the set as a body
Fixed #83 : ValidateConceptEvaluator : Support BNF and SYA Concepts
Fixed #84 : ExpressionParser: Implement the parser as a standard parser
Fixed #85 : Services: Give order to services
Fixed #86 : cannot manage smart_get_attr(the short, color)

src/core/sheerka/services/SheerkaEvaluateRules.py

@@ -111,13 +111,23 @@ class SheerkaEvaluateRules(BaseService):
 
         return expect_one(context, results)
 
-    def evaluate_conditions(self, context, conditions, bag):
+    def evaluate_conditions(self, context, conditions, bag, missing_vars=None):
+        """
+        Evaluate the conditions
+        :param context:
+        :param conditions:
+        :param bag: variables that are supposed to be in short term memory
+        :param missing_vars: if initialized to a set, keeps tracks of the missing variables
+        :return:
+        """
         bag_variables = set(bag.keys())
 
         results = []
         for compiled_condition in conditions:
 
             if compiled_condition.variables.intersection(bag_variables) != compiled_condition.variables:
+                if isinstance(missing_vars, set):
+                    missing_vars.update(compiled_condition.variables - bag_variables)
                 continue
 
             if compiled_condition.not_variables.intersection(bag_variables):
@@ -131,11 +141,12 @@ class SheerkaEvaluateRules(BaseService):
 
                 # do not forget to reset the 'is_evaluated' in the case of a concept
                 for concept in compiled_condition.concepts_to_reset:
-                    concept.get_metadata().is_evaluated = False
+                    concept.get_hints().is_evaluated = False
 
                 evaluator = self.evaluators_by_name[compiled_condition.evaluator_type]
                 res = evaluator.eval(context, compiled_condition.return_value)
-                if res.status and isinstance(res.body, bool) and res.body:
+                value = context.sheerka.objvalue(res.body)
+                if res.status and isinstance(value, bool) and value:
                     # one successful value found. No need to look any further
                     results = [res]  # don't we care about the other failing results ?
                     break