Refactored to use a single implementation for concept evaluation

evaluators/AddConceptEvaluator.py

@@ -3,6 +3,7 @@ from core.builtin_concepts import ParserResultConcept, ReturnValueConcept
 from core.builtin_helpers import get_names
 from core.concept import Concept
 from evaluators.BaseEvaluator import OneReturnValueEvaluator
+from parsers.BaseParser import NotInitializedNode
 from parsers.ConceptLexerParser import ParsingExpression, ParsingExpressionVisitor
 from parsers.DefaultParser import DefConceptNode
 
@@ -58,7 +59,7 @@ class AddConceptEvaluator(OneReturnValueEvaluator):
             # put back the sources
             part_ret_val = getattr(def_concept_node, prop)
             if not isinstance(part_ret_val, ReturnValueConcept) or not part_ret_val.status:
-                continue  # not quite sure that it's possible
+                continue  # Nothing to do is not initialized
 
             # update the parts
             source = self.get_source(part_ret_val)
@@ -82,7 +83,8 @@ class AddConceptEvaluator(OneReturnValueEvaluator):
         # finish initialisation
         concept.init_key(def_concept_node.name.tokens)
         concept.add_codes(def_concept_node.get_asts())
-        if sheerka.is_success(def_concept_node.definition):
+        if not isinstance(def_concept_node.definition, NotInitializedNode) and \
+            sheerka.is_success(def_concept_node.definition):
             concept.bnf = def_concept_node.definition.value.value
 
         ret = sheerka.create_new_concept(context, concept)