I can define and eval BNF definitions

evaluators/AddConceptEvaluator.py

@@ -1,14 +1,13 @@
 from core.ast.nodes import python_to_concept
-from core.builtin_concepts import ParserResultConcept, ReturnValueConcept, BuiltinConcepts
+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.ConceptLexerParser import ParsingExpression, ParsingExpressionVisitor
 from parsers.DefaultParser import DefConceptNode
-import functools
 import logging
 
-from parsers.PythonParser import PythonGetNamesVisitor, PythonNode
+from parsers.PythonParser import PythonNode
 
 log = logging.getLogger(__name__)
 
@@ -23,7 +22,12 @@ class ConceptOrRuleNameVisitor(ParsingExpressionVisitor):
         self.names = set()
 
     def visit_ConceptMatch(self, node):
-        self.names.add(node.rule_name or node.concept_name)
+        if node.rule_name:
+            self.names.add(node.rule_name)
+        elif isinstance(node.concept, Concept):
+            self.names.add(node.concept.name)
+        else:
+            self.names.add(node.concept)
 
     def visit_all(self, node):
         if node.rule_name: