Hints for memb/2 added.

1 files changed, 14 insertions, 4 deletions

diff --git a/prolog/problems/lists/memb_2/common.py b/prolog/problems/lists/memb_2/common.py
index 9ac56f6..e04535a 100644
--- a/prolog/problems/lists/memb_2/common.py
+++ b/prolog/problems/lists/memb_2/common.py
@@ -22,6 +22,8 @@ hint_type = {
     'eq_instead_of_equ_markup': HintPopup('eq_instead_of_equ_markup'),
     'eq_instead_of_equ': Hint('eq_instead_of_equ'),
     'predicate_always_false': Hint('predicate_always_false'),
+    'base_case': Hint('base_case'),
+    'timeout': Hint('timeout'),
     'final_hint': Hint('final_hint'),
 }
 
@@ -59,21 +61,29 @@ def hint(code, aux_code):
     try:
         engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
 
-        # gender testing is redundant
-        # this is not necessarily wrong, but worth mentioning anyway
+        # strict equality testing instead of simple matching
+        # this is usually (but not necessarily) wrong
         targets = [prolog.util.Token('EQ', '==')]
         marks = [(t.pos, t.pos + len(t.val)) for t in tokens if t in targets]
         if marks:
             return [{'id': 'eq_instead_of_equ_markup', 'start': m[0], 'end': m[1]} for m in marks] + \
                    [{'id': 'eq_instead_of_equ'}]
 
+        # recursion is getting bigger and bigger
+
+
         # target predicate seems to always be false
-        if not prolog.engine.ask_truth(engine_id, 'grandparent(_, _)'):
+        if not prolog.engine.ask_truthTO(engine_id, 'memb(_, _)'):
             return [{'id': 'predicate_always_false'}]
 
+        # missing/failed base case
+        if not prolog.engine.ask_truthTO(engine_id, 'memb(qq, [qq|_])'):
+            return [{'id': 'base_case'}]
+
+        # TODO: Tim, can we include 'fail'-used as a general hint?
 
     except socket.timeout as ex:
-        pass
+        return [{'id': 'timeout'}]
 
     finally:
         if engine_id: