Enhanced complex concepts handling

tests/test_sheerka_non_reg.py

@@ -401,6 +401,48 @@ def test_i_can_eval_bnf_definitions_from_separate_instances():
     assert res[0].value.props["a"] == Property("a", sheerka.new(concept_a.key, body="one two").init_key())
 
 
+def test_i_can_eval_a_mix_with_bnf_and_python():
+    sheerka = get_sheerka()
+
+    sheerka.evaluate_user_input("def concept one as 1")
+    sheerka.evaluate_user_input("def concept twenties from bnf 'twenty' one as 20 + one")
+
+    res = sheerka.evaluate_user_input("twenty one + 1")
+    assert len(res) == 1
+    assert res[0].status
+    assert res[0].body == 22
+
+
+def test_i_can_eval_a_mix_with_bnf_and_python_when_rule_name():
+    sheerka = get_sheerka()
+
+    sheerka.evaluate_user_input("def concept one as 1")
+    sheerka.evaluate_user_input("def concept two as 2")
+    sheerka.evaluate_user_input("def concept twenties from bnf 'twenty' (one|two)=unit as 20 + unit")
+
+    assert sheerka.evaluate_user_input("eval twenty one")[0].body == 21
+
+    res = sheerka.evaluate_user_input("twenty one + 1")
+    assert len(res) == 1
+    assert res[0].status
+    assert res[0].body == 22
+
+
+def test_i_can_eval_a_more_complicated_mix_with_bnf_and_python():
+    sheerka = get_sheerka()
+
+    sheerka.evaluate_user_input("def concept one as 1")
+    sheerka.evaluate_user_input("def concept two as 2")
+    sheerka.evaluate_user_input("def concept twenties from bnf 'twenty' (one|two)=unit as 20 + unit")
+
+    assert sheerka.evaluate_user_input("eval twenty one")[0].body == 21
+
+    res = sheerka.evaluate_user_input("twenty one + twenty two")
+    assert len(res) == 1
+    assert res[0].status
+    assert res[0].body == 43
+
+
 def test_i_can_say_that_a_concept_isa_another_concept():
     sheerka = get_sheerka()
     sheerka.evaluate_user_input("def concept foo")