1 files changed, 77 insertions, 0 deletions
diff --git a/prolog/problems/family_relations/brother_2/common.py b/prolog/problems/family_relations/brother_2/common.py
index 6038a13..41512e6 100644
--- a/prolog/problems/family_relations/brother_2/common.py
+++ b/prolog/problems/family_relations/brother_2/common.py
@@ -13,3 +13,80 @@ brother(X, Y) :-
   male(X),
   X \== Y.
 '''
+
+import prolog.engine
+import prolog.util
+import server.problems
+import socket
+
+def test(session, program):
+    # TODO: change queries and answers (these are for sister/2)
+    # Test queries and expected answers (values of X).
+    queries = [
+        ('sister(melanie, X)', set(['andrew'])),
+        ('sister(X, andrew)', set(['melanie'])),
+        ('sister(X, _)', set(['michelle', 'daniela', 'patricia', 'luana', 'sally', 'melanie', 'nevia', 'vanessa', 'anna'])),
+    ]
+
+    code = program + '\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:
+            return 0, len(queries)
+
+        n_correct = 0
+        for query, solution in queries:
+            answers, error = prolog.engine.ask_all(engine_id, query=query, timeout=1.0)
+            if answers and answers[-1] != 'timed out':
+                values_x = set([ans.get('X') for ans, constraints in answers])
+                if values_x == solution:
+                    n_correct += 1
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    return n_correct, len(queries)
+
+def general_hint():
+    pass
+
+def hint(session, program):
+    # tokens = prolog.util.tokenize(program)
+
+    code = program + '\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 must be male
+        if prolog.engine.ask_truth(engine_id, 'female(X), brother(X, _)'):
+            return [{'id': 'x_must_be_male'}]
+
+        # X and Y must have a common parent
+        if prolog.engine.ask_truth(engine_id,
+            'brother(X, Y), \+ (parent(P, X), parent(P, Y))'):
+            return [{'id': 'common_parent_needed'}]
+
+        # Y can be of any gender, incl. female
+        if prolog.engine.ask_one(engine_id,
+            'brother(_, Y), female(Y)') == 'false':
+            return [{'id': 'Y_can_be_of_any_gender'}]
+
+        # X and Y must be different
+        ans = prolog.engine.ask_one(engine_id,
+            'setof(X, (member(X, [william, alessandro, andrew]), brother(X, X)), L), length(L, N).')
+        if ans.get('N') == '3':
+            return [{'id': 'x_y_must_be_different'}]
+
+    except socket.timeout as ex:
+        pass
+
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
+    return None