Merge pull request #24 from cdamours/unused-element

Don't raise UnusedElementError when used has more elems than Grammar

pyleri/grammar.py

@@ -127,7 +127,7 @@ def __new__(mcs, name, bases, attrs, **kwargs):
             elems = {
                 elem for elem in attrs['_order']
                 if isinstance(attrs[elem], Element)}
-            if used != elems:
+            if elems - used:
                 raise UnusedElementError(
                     'Unused element(s) found: {}'.format(
                         ', '.join(elems - used)))

test/test_choice.py

@@ -10,6 +10,7 @@
     Sequence,
     Choice,
     Keyword,
+    Regex,
 )  # nopep8
 
 
@@ -39,6 +40,24 @@ def test_choice_first_match(self):
         self.assertFalse(grammar.parse(' hi iris ').is_valid)
         self.assertFalse(grammar.parse(' hi sasha ').is_valid)
 
+    def test_choice_with_named_elements(self):
+        int_value = Regex(r"\d+")
+        int_value.name = "INT_VALUE"
+
+        float_value = Regex(r"\d+(\.\d+)?")
+        float_value.name = "FLOAT_VALUE"
+
+        choice = Choice(float_value, int_value)
+        grammar = create_grammar(choice)
+
+        result = grammar.parse("invalid")
+
+        expecting = {str(element) for element in result.expecting}
+
+        self.assertIn('"INT_VALUE"', expecting)
+        self.assertIn('"FLOAT_VALUE"', expecting)
+        self.assertNotIn("Regex", expecting)
+
 
 if __name__ == '__main__':
     unittest.main()