Hints for insert/3 added.

1 files changed, 15 insertions, 13 deletions

diff --git a/prolog/problems/lists/insert_3/common.py b/prolog/problems/lists/insert_3/common.py
index 5b049f7..3b56cf3 100644
--- a/prolog/problems/lists/insert_3/common.py
+++ b/prolog/problems/lists/insert_3/common.py
@@ -26,10 +26,11 @@ hint_type = {
     'predicate_always_false': Hint('predicate_always_false'),
     'base_case': Hint('base_case'),
     'timeout': Hint('timeout'),
-    'del_from_empty_list_success': Hint('del_from_empty_list_success'),
     'lost_heads': Hint('lost_heads'),
     'recursive_case': Hint('recursive_case'),
     'leading_heads_all_x': Hint('leading_heads_all_x'),
+    'ins_results_in_empty_list': Hint('ins_results_in_empty_list'),
+    'ins_results_in_arbitrary_result': Hint('ins_results_in_arbitrary_result'),
 }
 
 test_cases = [
@@ -77,34 +78,35 @@ def hint(code, aux_code):
         # recursion is getting bigger and bigger
 
 
-        # deleting from empty list succeeds with an emtpy list result
-        if prolog.engine.ask_truthTO(engine_id, 'del(_, [], _)'):
-            return [{'id': 'del_from_empty_list_success'}]
+        # inserting an element succeeds with an emtpy list result
+        if prolog.engine.ask_truthTO(engine_id, 'insert(_, _, [])'):
+            return [{'id': 'ins_results_in_empty_list'}]
+
+        # inserting an element succeeds with an arbitrary result
+        if prolog.engine.ask_truth(engine_id, 'insert(_, _, L), var(L)'):
+            return [{'id': 'ins_results_in_arbitrary_result'}]
 
         # missing/failed base case
-        if not prolog.engine.ask_one(engine_id, 'del(qQ, [qQ,qa,qb,qc], [qa,qb,qc])'):
+        if not prolog.engine.ask_one(engine_id, 'insert(qQ, [qa,qb,qc], [qQ,qa,qb,qc])'):
             return [{'id': 'base_case'}]
 
         # target predicate seems to always be false
-        if not prolog.engine.ask_truth(engine_id, 'del(_, [_,_,_,_,_,_], _)'):
+        if not prolog.engine.ask_truth(engine_id, 'insert(_, [_,_,_,_,_,_], _)'):
             return [{'id': 'predicate_always_false'}]
 
         # forgot to put list head(s) back in the list when deleting an element
-        if prolog.engine.ask_truth(engine_id, 'del(q, [a,b,c,d,q,x,y,z], [x,y,z])'):
+        if prolog.engine.ask_truth(engine_id, 'insert(q, [a,b,c,d,x,y,z], [q,x,y,z])'):
             return [{'id': 'lost_heads'}]
 
         # used [X|T] instead of more general [H|T] in recursive case
         if prolog.engine.ask_truth(engine_id, \
-                'findall(NL, del(q, [q,q,q,a,b,c], NL), [[q,q,a,b,c],[q,q,a,b,c],[q,q,a,b,c]]).') and \
-           not prolog.engine.ask_truth(engine_id, 'del(q, [a,b,c,q,x,y,z], [a,b,c,x,y,z])'):
+                'findall(NL, insert(q, [a,b,c], NL), [[q,a,b,c], [q,q,b,c], [q,q,q,c], [q,q,q,q]]).') and \
+           not prolog.engine.ask_truth(engine_id, 'insert(q, [a,b,c,x,y,z], [a,b,c,q,x,y,z])'):
             return [{'id': 'leading_heads_all_x'}]
 
-        # L=[H|T] at the end of the rule; this can be detected with test cases and can be wrong (in some sense)
-        # TODO: implement it, and provide a good explanation (might be hard)
-
         # base case works, the recursive doesn't (but it doesn't timeout)
         # this may be left as the last, most generic hint
-        if not prolog.engine.ask_truth(engine_id, 'del(qQ, [qa,qb,qQ,qc], [qa,qb,qc])'):
+        if not prolog.engine.ask_truth(engine_id, 'insert(qQ, [qa,qb,qc], [qa,qb,qQ,qc])'):
             return [{'id': 'recursive_case'}]