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authorTimotej Lazar <timotej.lazar@fri.uni-lj.si>2016-03-17 15:41:44 +0100
committerTimotej Lazar <timotej.lazar@fri.uni-lj.si>2016-03-17 15:41:44 +0100
commitc1cc16c4088cb68d205342450493957f17a71c9a (patch)
tree1da578bc17d024fb54f45fcd686283e1aa55f3a3 /prolog/problems/lists_advanced/max_2
parentcf4e59c9d6bce337514fc7d77120baced0d6d7bc (diff)
Prolog: add generic recursion hints for lists_advanced problems
TODO modify texts in */sl.py where appropriate.
Diffstat (limited to 'prolog/problems/lists_advanced/max_2')
-rw-r--r--prolog/problems/lists_advanced/max_2/common.py50
-rw-r--r--prolog/problems/lists_advanced/max_2/en.py2
-rw-r--r--prolog/problems/lists_advanced/max_2/sl.py38
3 files changed, 81 insertions, 9 deletions
diff --git a/prolog/problems/lists_advanced/max_2/common.py b/prolog/problems/lists_advanced/max_2/common.py
index 92cf793..3fe5f94 100644
--- a/prolog/problems/lists_advanced/max_2/common.py
+++ b/prolog/problems/lists_advanced/max_2/common.py
@@ -1,8 +1,9 @@
-# coding=utf-8
-
from operator import itemgetter
+import socket
+
import prolog.engine
-import server.problems
+import prolog.util
+from server.hints import Hint, HintPopup
id = 109
number = 16
@@ -18,6 +19,15 @@ max([H|T], Max):-
H =< Max1, Max is Max1 ).
'''
+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'),
+}
+
test_cases = [
('max([15], X)',
[{'X': '15'}]),
@@ -49,5 +59,37 @@ 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'}]
+
+ # missing/failed base case
+ if not prolog.engine.ask_truthTO(engine_id, 'max([-45], 45)'):
+ return [{'id': 'base_case'}]
+
+ # target predicate seems to always be false
+ if not prolog.engine.ask_truthTO(engine_id, 'max(_, _)'):
+ 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, 'max([2, 41, -22], 41)'):
+ return [{'id': 'recursive_case'}]
+
+ except socket.timeout as ex:
+ return [{'id': 'timeout'}]
+
+ finally:
+ if engine_id:
+ prolog.engine.destroy(engine_id)
+
return []
diff --git a/prolog/problems/lists_advanced/max_2/en.py b/prolog/problems/lists_advanced/max_2/en.py
index c4bc7e2..59c00f0 100644
--- a/prolog/problems/lists_advanced/max_2/en.py
+++ b/prolog/problems/lists_advanced/max_2/en.py
@@ -1,5 +1,3 @@
-# coding=utf-8
-
name = 'max/2'
slug = 'find the largest element in list'
diff --git a/prolog/problems/lists_advanced/max_2/sl.py b/prolog/problems/lists_advanced/max_2/sl.py
index 7a0d07a..86159aa 100644
--- a/prolog/problems/lists_advanced/max_2/sl.py
+++ b/prolog/problems/lists_advanced/max_2/sl.py
@@ -1,5 +1,3 @@
-# coding=utf-8
-
name = 'max/2'
slug = 'Poišči največji element v danem seznamu'
@@ -12,4 +10,38 @@ description = '''\
M = 3.
</pre>'''
-hint = {}
+hint = {
+ 'eq_instead_of_equ': '''\
+<p>Operator <code>==</code> je strožji od operatorja <code>=</code> v smislu, da je za slednjega dovolj,
+da elementa lahko naredi enaka (unifikacija). Morda z uporabo <code>=</code> narediš predikat
+<code>memb/2</code> delujoč tudi v kakšni drugi smeri.</p>
+<p>Seveda pa lahko nalogo rešiš brez obeh omenjenih operatorjev, spomni se, da lahko unifikacijo narediš
+implicitno že kar v argumentih predikata (glavi stavka).</p>
+''',
+
+ 'eq_instead_of_equ_markup': '''\
+<p>Morda bi bil bolj primeren operator za unifikacijo (=)?</p>
+''',
+
+ 'base_case': '''\
+<p>Si pomislil na robni pogoj? Kaj je najbolj enostaven primer, ko je element v seznamu?
+Do katerega elementa najlažje prideš?</p>
+''',
+
+ 'recursive_case': '''\
+<p>Robni primer deluje. Kaj pa rekurzivni, splošni, primer?</p>
+''',
+
+ 'predicate_always_false': '''\
+<p>Vse kaže, da tvoj predikat vedno vrne "false". Si mu dal pravilno ime, si se morda pri imenu zatipkal?</p>
+<p>Če je ime pravilno, se morda splača preveriti tudi, če se nisi zatipkal kje drugje,
+je morda kakšna pika namesto vejice ali obratno, morda kakšna spremenljivka z malo začetnico?</p>
+<p>Možno je seveda tudi, da so tvoji pogoji prestrogi ali celo nemogoči (kot bi bila npr. zahteva,
+da je <code>X</code> hkrati starš in sestra od <code>Y</code> ali kaj podobno zlobnega).</p>
+''',
+
+ 'timeout': '''\
+<p>Je morda na delu potencialno neskončna rekurzija? Kako se bo ustavila?</p>
+<p>Morda pa je kriv tudi manjkajoč, neustrezen ali preprosto nekompatibilen (s splošnim primerom) robni pogoj?</p>
+''',
+}