Implemented a first and basic version of a Rete rule engine

tests/core/test_builtin_helpers.py

@@ -1,10 +1,9 @@
-import ast
+import pytest
 
 import core.builtin_helpers
-import pytest
 from core.builtin_concepts import ReturnValueConcept, BuiltinConcepts
 from core.concept import Concept
-
+from core.global_symbols import NotInit
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
 
 
@@ -157,6 +156,32 @@ class TestBuiltinHelpers(TestUsingMemoryBasedSheerka):
         res = core.builtin_helpers.resolve_ambiguity(context, concepts)
         assert [c.name for c in res] == expected
 
+    @pytest.mark.parametrize("pre, expected", [
+        ("x and y", False),
+        ("is_question()", True),
+        (" is_question ( ) ", True),
+        ("context.in_context(BuiltinConcepts.EVAL_QUESTION_REQUESTED)", True),
+        (" context . in_context ( BuiltinConcepts . EVAL_QUESTION_REQUESTED ) ", True),
+        (None, False),
+        ("", False),
+        (NotInit, False),
+        ("is _ question()", False),
+        ("is_ question()", False),
+        ("is _question()", False),
+        ("context.in _context(BuiltinConcepts.EVAL_QUESTION_REQUESTED)", False),
+        ("not is_question()", False),
+        ("not context.in_context(BuiltinConcepts.EVAL_QUESTION_REQUESTED)", False),
+        ("is_question() and True", True),
+        ("is_question() and False", True),  # don't care about the second argument if it is not related to question
+        ("is_question() and xxx", True),  # don't care about the second argument if it is not related to question
+        ("is_question() and not is_question()", False),  # error ?
+        ("is_question() and not context.in_context(BuiltinConcepts.EVAL_QUESTION_REQUESTED)", False),  # error ?
+    ])
+    def test_is_a_question(self, pre, expected):
+        sheerka, context = self.init_test().unpack()
+        concept = Concept("foo", pre=pre)
+        assert core.builtin_helpers.is_a_question(context, concept) == expected
+
     # @pytest.mark.parametrize("return_values", [
     #     None,
     #     []