From 0d32abe688f0636988090f653f75bc33616ad610 Mon Sep 17 00:00:00 2001
From: Timotej Lazar <timotej.lazar@fri.uni-lj.si>
Date: Tue, 29 Mar 2016 19:00:23 +0200
Subject: Prolog: add triggers for is_sorted/1 hints

---
 prolog/problems/sorting/is_sorted_1/common.py | 95 +++++++++++++++++++++++++--
 1 file changed, 90 insertions(+), 5 deletions(-)

(limited to 'prolog/problems/sorting/is_sorted_1/common.py')

diff --git a/prolog/problems/sorting/is_sorted_1/common.py b/prolog/problems/sorting/is_sorted_1/common.py
index 0e8a49d..dc97712 100644
--- a/prolog/problems/sorting/is_sorted_1/common.py
+++ b/prolog/problems/sorting/is_sorted_1/common.py
@@ -1,11 +1,11 @@
-# coding=utf-8
-
 from operator import itemgetter
+import socket
+
 import prolog.engine
-import server.problems
+from server.hints import Hint, HintPopup
 
 id = 121
-number = 28
+number = 10
 visible = False
 facts = None
 
@@ -17,6 +17,21 @@ is_sorted([H1,H2|T]) :-
   is_sorted([H2|T]).
 '''
 
+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'),
+    'recursive_case': Hint('recursive_case'),
+    'timeout': Hint('timeout'),
+    '[]_base_case_missing': Hint('[]_base_case_missing'),
+    'duplicates_fail': Hint('duplicates_fail'),
+    'H1_instead_of_H2_sent_into_recursion': Hint('H1_instead_of_H2_sent_into_recursion'),
+    'base_case_at_len_1_missing': Hint('base_case_at_len_1_missing'),
+    'both_heads_omitted_from_recursion': Hint('both_heads_omitted_from_recursion'),
+    'min_used': Hint('min_used'),
+}
+
 test_cases = [
     ('is_sorted([])',
         [{}]),
@@ -32,6 +47,8 @@ test_cases = [
         [{}]),
     ('\+ is_sorted([3, 4, 5, 6, 1, 2, 3, 0])',
         [{}]),
+    ('\+ is_sorted([3, 13, 6, 39])',
+        [{}]),
 ]
 
 def test(code, aux_code):
@@ -54,5 +71,73 @@ 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'}]
+
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                is_sorted([1, 3, 5, 6, 9]),
+                \+ is_sorted([1, 9, 3, 6]),
+                is_sorted([39]),
+                \+ is_sorted([])'''):
+            return [{'id': '[]_base_case_missing'}]
+
+        # H1 < H2 instead of H1 =< H2
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                is_sorted([1, 3, 5, 6, 9]),
+                \+ is_sorted([1, 9, 3, 6]),
+                \+ is_sorted([1, 3, 5, 5, 7, 9])'''):
+            return [{'id': 'duplicates_fail'}]
+
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                \+ is_sorted([3, 13, 1, 39]),
+                is_sorted([3, 13, 16, 39]),
+                is_sorted([3, 13, 6, 39])'''):
+            return [{'id': 'H1_instead_of_H2_sent_into_recursion'}]
+
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                (is_sorted([13, 39])
+                 ;
+                 is_sorted([])),
+                \+ is_sorted([39])'''):
+            return [{'id': 'base_case_at_len_1_missing'}]
+
+        if prolog.engine.ask_truthTO(engine_id, '''\
+                \+ is_sorted([1, 0, 2, 25, 39]),
+                is_sorted([1, 3, 9, 16, 39]),
+                is_sorted([1, 3, 2, 16, 39])'''):
+            return [{'id': 'both_heads_omitted_from_recursion'}]
+
+        if any(t.val == 'min' for t in tokens):
+            return [{'id': 'min_used'}]
+
+        # missing/failed base case
+        if not prolog.engine.ask_truthTO(engine_id, 'is_sorted([])'):
+            return [{'id': 'base_case'}]
+
+        # target predicate seems to always be false
+        if not prolog.engine.ask_truthTO(engine_id, 'is_sorted(_)'):
+            return [{'id': 'predicate_always_false'}]
+
+        # 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, 'is_sorted([-2, 41, 82, 100])'):
+            return [{'id': 'recursive_case'}]
+
+    except socket.timeout as ex:
+        return [{'id': 'timeout'}]
+
+    finally:
+        if engine_id:
+            prolog.engine.destroy(engine_id)
+
     return []
-- 
cgit v1.2.1