From ada33434a28fb1cf90dd77ae6c01860e0445c59c Mon Sep 17 00:00:00 2001
From: Aleksander Sadikov <aleksander.sadikov@fri.uni-lj.si>
Date: Fri, 11 Mar 2016 02:12:16 +0100
Subject: Plans for dup/2 added.

---
 prolog/problems/lists/dup_2/common.py | 72 ++++++++++++++++++++++++++++++++++-
 1 file changed, 71 insertions(+), 1 deletion(-)

(limited to 'prolog/problems/lists/dup_2/common.py')

diff --git a/prolog/problems/lists/dup_2/common.py b/prolog/problems/lists/dup_2/common.py
index d4ebffe..a27eb4b 100644
--- a/prolog/problems/lists/dup_2/common.py
+++ b/prolog/problems/lists/dup_2/common.py
@@ -2,6 +2,9 @@
 
 from operator import itemgetter
 import prolog.engine
+import prolog.util
+import socket
+from server.hints import Hint, HintPopup
 import server.problems
 
 id = 110
@@ -15,6 +18,19 @@ dup([H|T], [H,H|TT]) :-
   dup(T, TT).
 '''
 
+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'),
+    '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 = [
     ('dup([], X)',
         [{'X': '[]'}]),
@@ -46,5 +62,59 @@ def test(code, aux_code):
     return n_correct, len(test_cases), hints
 
 def hint(code, aux_code):
-    # TODO
+    tokens = prolog.util.tokenize(code)
+
+    try:
+        engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
+
+        # 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
+
+
+        # 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, '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, '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, '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, 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'}]
+
+        # 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, 'insert(qQ, [qa,qb,qc], [qa,qb,qQ,qc])'):
+            return [{'id': 'recursive_case'}]
+
+
+    except socket.timeout as ex:
+        return [{'id': 'timeout'}]
+
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
     return []
-- 
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