Fixed #68: Implement SheerkaQL

Fixed #70: SheerkaFilterManager : Pipe functions
Fixed #71: SheerkaFilterManager : filter_objects
Fixed #75: SheerkaMemory: Enhance memory() to use the filtering capabilities
Fixed #76: SheerkaEvaluateConcept: Concepts that modify the state of the system must not be evaluated during question

tests/core/test_builtin_helpers.py

@@ -182,6 +182,17 @@ class TestBuiltinHelpers(TestUsingMemoryBasedSheerka):
         concept = Concept("foo", pre=pre)
         assert core.builtin_helpers.is_a_question(context, concept) == expected
 
+    def test_context_hints_are_reset_when_call_evaluate_from_source(self):
+        sheerka, context, one = self.init_concepts(Concept("one", body="1"))
+        context.add_to_global_hints(BuiltinConcepts.EVAL_BODY_REQUESTED)
+        context.add_to_protected_hints(BuiltinConcepts.EVAL_BODY_REQUESTED)
+        context.add_to_private_hints(BuiltinConcepts.EVAL_BODY_REQUESTED)
+
+        res = core.builtin_helpers.evaluate_from_source(context, "one", eval_body=False)
+
+        evaluated = [r for r in res if r.status][0].body
+        assert evaluated.body is NotInit
+
     # @pytest.mark.parametrize("return_values", [
     #     None,
     #     []