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)

tests/core/test_SheerkaIsAManager.py

@@ -84,7 +84,19 @@ class TestSheerkaIsAManager(TestUsingMemoryBasedSheerka):
         assert sheerka.isinstance(error, BuiltinConcepts.NOT_A_SET)
         assert error.body == one
 
-    def test_isa_and_isa_group(self):
+    def test_isa(self):
+        sheerka, context, blue, color = self.init_concepts(Concept("blue"), Concept("color"))
+
+        assert not sheerka.isa(blue, color)
+
+        sheerka.set_isa(context, blue, color)
+        assert sheerka.isa(blue, color)
+
+        # isa tests the id of a concept, not it's content
+        another_color_instance_but_with_a_body = sheerka.new(color, body="a body")
+        assert sheerka.isa(blue, another_color_instance_but_with_a_body)
+
+    def test_isaset(self):
         sheerka, context, group, foo = self.init_concepts(Concept("group"), Concept("foo"))
 
         assert not sheerka.isaset(context, group)