Fixed first token recognition when creating bnf concepts

tests/parsers/test_DefaultParser.py

@@ -187,9 +187,9 @@ func(a)
         return_value = res.value
 
         assert not res.status
-        assert isinstance(return_value, ParserResultConcept)
-        assert isinstance(return_value.value[0], SyntaxErrorNode)
-        assert return_value.value[0].message == "Indentation not found."
+        assert sheerka.isinstance(return_value, BuiltinConcepts.ERROR)
+        assert isinstance(return_value.body[0], SyntaxErrorNode)
+        assert return_value.body[0].message == "Indentation not found."
 
     def test_indentation_is_not_allowed_if_the_colon_is_missing(self):
         text = """
@@ -213,24 +213,22 @@ def concept add one to a as
         return_value = res.value
 
         assert not res.status
-        assert isinstance(return_value, ParserResultConcept)
-        assert isinstance(return_value.value[0], SyntaxErrorNode)
-        assert return_value.value[0].message == "Name is mandatory"
+        assert sheerka.isinstance(return_value, BuiltinConcepts.ERROR)
+        assert isinstance(return_value.body[0], SyntaxErrorNode)
+        assert return_value.body[0].message == "Name is mandatory"
 
     def test_concept_keyword_is_mandatory_but_the_concept_is_recognized(self):
         text = "def hello as a where b pre c post d"
 
-        expected_concept = get_def_concept(name="hello", body="a ", where="b ", pre="c ", post="d")
         sheerka, context, parser = self.init_parser()
         res = parser.parse(context, ParserInput(text))
         return_value = res.value
 
         assert not res.status
-        assert isinstance(return_value, ParserResultConcept)
-        assert isinstance(return_value.value[0], UnexpectedTokenErrorNode)
-        assert return_value.value[0].message == "Syntax error."
-        assert return_value.value[0].expected_tokens == [Keywords.CONCEPT]
-        assert return_value.try_parsed == expected_concept
+        assert sheerka.isinstance(return_value, BuiltinConcepts.ERROR)
+        assert isinstance(return_value.body[0], UnexpectedTokenErrorNode)
+        assert return_value.body[0].message == "Syntax error."
+        assert return_value.body[0].expected_tokens == [Keywords.CONCEPT]
 
     @pytest.mark.parametrize("text", [
         "def concept hello where 1+",
@@ -254,7 +252,8 @@ def concept add one to a as
         return_value = res.value
 
         assert not res.status
-        assert return_value.value == [SyntaxErrorNode([], "Newline are not allowed in name.")]
+        assert sheerka.isinstance(return_value, BuiltinConcepts.ERROR)
+        assert return_value.body == [SyntaxErrorNode([], "Newline are not allowed in name.")]
 
     def test_i_can_parse_def_concept_from_bnf(self):
         text = "def concept name from bnf a_concept | 'a_string' as __definition[0]"
@@ -289,7 +288,8 @@ def concept add one to a as
         res = parser.parse(context, ParserInput(text))
 
         assert not res.status
-        assert res.value.value[0] == SyntaxErrorNode([], "Empty declaration")
+        assert sheerka.isinstance(res.value, BuiltinConcepts.ERROR)
+        assert res.value.body[0] == SyntaxErrorNode([], "Empty declaration")
 
     @pytest.mark.parametrize("text", [
         "def concept addition from a plus b as a + b",
@@ -341,7 +341,7 @@ def concept add one to a as
         res = parser.parse(context, ParserInput(text))
 
         assert not res.status
-        assert isinstance(res.body, ParserResultConcept)
+        assert sheerka.isinstance(res.body, BuiltinConcepts.ERROR)
         assert isinstance(res.body.body[0], UnexpectedTokenErrorNode)
 
     @pytest.mark.parametrize("text, error_msg, error_text", [