Enhanced PythonEvaluator to accept concepts

evaluators/ConceptEvaluator.py

@@ -1,4 +1,5 @@
 from core.builtin_concepts import ParserResultConcept, BuiltinConcepts
+import core.builtin_helpers
 from core.concept import Concept, ConceptParts
 from evaluators.BaseEvaluator import OneReturnValueEvaluator
 import logging
@@ -47,13 +48,14 @@ class ConceptEvaluator(OneReturnValueEvaluator):
                     sheerka.new(BuiltinConcepts.PROPERTY_EVAL_ERROR, body=prop, concept=concept, error=res.value),
                     parents=[return_value])
 
-        # Evaluate body
+        # Returns the concept when no body
         if ConceptParts.BODY not in concept.codes:
             return sheerka.ret(self.name, True, concept, parents=[return_value])
 
+        # Evaluate the body otherwise
         body = concept.codes[ConceptParts.BODY]
         if body is None:
-            return None  # seems weird
+            raise NotImplementedError("Seems weird !")
 
         sub_context = context.push(self.name, "Evaluating body", concept)
         res = self.evaluate_parsing(sheerka, sub_context, body)
@@ -61,5 +63,5 @@ class ConceptEvaluator(OneReturnValueEvaluator):
 
     def evaluate_parsing(self, sheerka, context, parsing_result):
         res = sheerka.chain_process(context, parsing_result, self.evaluation_steps)
-        res = sheerka.expect_one(context, res)
+        res = core.builtin_helpers.expect_one(context, res)
         return res