Fixed #101 : Implement PLURIAL

Fixed #103 : Implement PlurialNodeParser
Fixed #104 : Implement dynamic concept
Fixed #107 : PrepareEvalxxxEvaluator: context hints are lost on a second evaluation

tests/core/test_SheerkaEvaluateConcept.py

@@ -518,6 +518,29 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
         evaluated = sheerka.evaluate_concept(self.get_context(sheerka, False, False), concept)
         assert evaluated.key == concept.key
 
+    def test_i_can_evaluate_context_hint_multiple_times(self):
+        """
+        Previous behaviour (that we want to change)
+        When def concept foo as global_truth(xxx) pre yyy
+        the context hint for the global truth is set during the initialisation of the ast
+        if the body is computed straight away it's ok,
+        But if the concept is evaluated a second time, the asts is not computed again, so the context hint is not set
+        :return:
+        """
+        sheerka, context, foo = self.init_concepts(
+            Concept("foo", body="global_truth(in_context(BuiltinConcepts.EVAL_GLOBAL_TRUTH_REQUESTED))")
+        )
+
+        foo_instance = sheerka.new("foo")
+        evaluated = sheerka.evaluate_concept(context, foo_instance, eval_body=False)
+
+        assert ConceptParts.BODY in evaluated.get_compiled()
+        assert evaluated.body == NotInit
+        assert not evaluated.get_hints().is_evaluated
+
+        evaluated = sheerka.evaluate_concept(context, foo_instance, eval_body=True)  # evaluate the body this time
+        assert isinstance(evaluated.body, bool) and evaluated.body
+
     def test_i_can_apply_intermediate_where_condition_using_python(self):
         sheerka, context, one_1, one_str, plus = self.init_concepts(
             Concept("one", body="1"),
@@ -818,10 +841,14 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
         (Concept("foo"), False, []),
         (Concept("foo", pre="pre", post="post", ret="ret", where="where"), False, ["#pre#", "#post#"]),
         (Concept("foo", pre="pr", post="p", ret="r", where="w"), True,
-         ["#pre#", "#ret#", "#post#", "variables", "#body#"]),
+         ["#pre#", "variables", "#body#", "#ret#", "#post#"]),
+
+        (Concept("foo", pre="pre", body="body"), False, ["#pre#"]),
+        (Concept("foo", pre="pre", body="body"), True, ["#pre#", "variables", "#body#"]),
         (Concept("foo", pre="a").def_var("a"), False, ["variables", "#pre#"]),
         (Concept("foo", pre="self"), False, ["#body#", "#pre#"]),
         (Concept("foo", pre="self + a").def_var("a"), False, ["variables", "#body#", "#pre#"]),
+
         (Concept("foo", pre="self + a", ret="ret").def_var("a"), False, ["variables", "#body#", "#pre#"]),
         (Concept("foo", pre="self + a", ret="ret").def_var("a"), True, ["variables", "#body#", "#pre#", "#ret#"]),
         (Concept("foo", body="body"), False, [])