1 files changed, 100 insertions, 0 deletions
diff --git a/prolog/problems/family_relations/aunt_2/common.py b/prolog/problems/family_relations/aunt_2/common.py
index f0af2dc..ed291fc 100644
--- a/prolog/problems/family_relations/aunt_2/common.py
+++ b/prolog/problems/family_relations/aunt_2/common.py
@@ -17,3 +17,103 @@ aunt(X, Y) :-
   sister98(X, Z),
   parent(Z, Y).
 '''
+
+hint_type = {
+    'x_and_y_mixed_up': Hint('x_and_y_mixed_up'),
+    'precedence_fail': Hint('precedence_fail'),
+    'x_must_be_female': Hint('x_must_be_female'),
+    'aunt_vs_mother': Hint('aunt_vs_mother'),
+    'x_need_not_be_parent': Hint('x_need_not_be_parent'),
+    'y_need_not_be_parent': Hint('y_need_not_be_parent'),
+}
+
+test_cases = [
+    # TODO
+]
+
+def test(program, solved_problems):
+    code = (program + '\n' +
+            server.problems.solutions_for_problems('prolog', solved_problems) + '\n' +
+            server.problems.load_facts('prolog', facts).facts)
+
+    engine_id = None
+    try:
+        engine_id, output = prolog.engine.create(code=code, timeout=1.0)
+        if not engine_id or 'error' in map(itemgetter(0), output):
+            # Engine creation failed, or syntax error in code.
+            return 0, len(test_cases)
+
+        n_correct = 0
+        for query, answers in test_cases:
+            # Limit inferences for each solution to curb unbounded recursion.
+            limited = 'call_with_inference_limit(({}), 100000, _)'.format(query)
+            if prolog.engine.check_answers(engine_id, query=limited, answers=answers, timeout=1.0):
+                n_correct += 1
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    passed = n_correct == len(test_cases)
+    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_cases)}}]
+    return passed, hints
+
+def hint(program, solved_problems):
+    tokens = prolog.util.tokenize(program)
+
+    code = (program + '\n' +
+            server.problems.solutions_for_problems('prolog', solved_problems) + '\n' +
+            server.problems.load_facts('prolog', facts).facts)
+
+    engine_id = None
+    try:
+        engine_id, output = prolog.engine.create(code=code, timeout=1.0)
+        if not engine_id:
+            raise Exception('Prolog engine failed to create.')
+
+        # X and Y mixed up
+        # warning: knowledge base dependent
+        # independent: match on findall(X/Y, (sister(Y, P), parent(P, X)), L)
+        if prolog.engine.ask_truth(engine_id,
+            'findall(X/Y, aunt(X, Y), \
+             [vanessa/sally, patricia/sally, joanne/melanie, john/vanessa, susan/patricia])'):
+            return [{'id', 'x_and_y_mixed_up'}]
+
+        # precedence fail (AND block vs OR block)
+        # case in point: female(X), parent(P, Y), brother(P, X) ; sister(P, X)
+        # warning: knowledge base dependent
+        if prolog.util.Token('SEMI', ';') in tokens and prolog.engine.ask_truth(engine_id,
+            'findall(_, aunt(X, Y), L), length(L, 15)'):
+            return [{'id', 'precedence_fail'}]
+
+        # X must be female
+        if prolog.engine.ask_truth(engine_id,
+            'aunt(X, _), male(X)'):
+            return [{'id', 'x_must_be_female'}]
+
+        # X and P can be the same person
+        # this can occur if the problem is not solved using sister/2
+        if prolog.engine.ask_truth(engine_id,
+            'aunt(X, Y), mother(X, Y)'):
+            return [{'id', 'aunt_vs_mother'}]
+
+        # X does not necessarily need to be a parent
+        # perhaps risky as only one aunt that is not a parent exists in DB (melanie)
+        if prolog.engine.ask_one(engine_id,
+            'aunt(X, _), \+ parent(X, _)') == 'false':
+            return [{'id': 'x_need_not_be_parent'}]
+
+        # Y does not necessarily need to be a parent
+        # perhaps risky as only one such nephew exists in DB (susan)
+        if prolog.engine.ask_one(engine_id,
+            'aunt(_, Y), \+ parent(Y, _)') == 'false':
+            return [{'id': 'y_need_not_be_parent'}]
+
+    except socket.timeout as ex:
+        pass
+
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    return None
+