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author | Timotej Lazar <timotej.lazar@fri.uni-lj.si> | 2016-03-17 15:41:44 +0100 |
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committer | Timotej Lazar <timotej.lazar@fri.uni-lj.si> | 2016-03-17 15:41:44 +0100 |
commit | c1cc16c4088cb68d205342450493957f17a71c9a (patch) | |
tree | 1da578bc17d024fb54f45fcd686283e1aa55f3a3 /prolog/problems/lists_advanced/sum_2 | |
parent | cf4e59c9d6bce337514fc7d77120baced0d6d7bc (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/sum_2')
-rw-r--r-- | prolog/problems/lists_advanced/sum_2/common.py | 50 | ||||
-rw-r--r-- | prolog/problems/lists_advanced/sum_2/en.py | 2 | ||||
-rw-r--r-- | prolog/problems/lists_advanced/sum_2/sl.py | 38 |
3 files changed, 81 insertions, 9 deletions
diff --git a/prolog/problems/lists_advanced/sum_2/common.py b/prolog/problems/lists_advanced/sum_2/common.py index 000b4b0..00034ef 100644 --- a/prolog/problems/lists_advanced/sum_2/common.py +++ b/prolog/problems/lists_advanced/sum_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 = 118 number = 25 @@ -16,6 +17,15 @@ sum([H|T], Sum) :- Sum is SumT + H. ''' +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 = [ ('sum([], X)', [{'X': '0'}]), @@ -45,5 +55,37 @@ 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, 'sum([], 0)'): + return [{'id': 'base_case'}] + + # target predicate seems to always be false + if not prolog.engine.ask_truthTO(engine_id, 'sum(_, _)'): + 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, 'sum([2, 41, -22], 21)'): + 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/sum_2/en.py b/prolog/problems/lists_advanced/sum_2/en.py index b4dab45..767a6f4 100644 --- a/prolog/problems/lists_advanced/sum_2/en.py +++ b/prolog/problems/lists_advanced/sum_2/en.py @@ -1,5 +1,3 @@ -# coding=utf-8 - name = 'sum/2' slug = 'find the sum of all elements in list' diff --git a/prolog/problems/lists_advanced/sum_2/sl.py b/prolog/problems/lists_advanced/sum_2/sl.py index cc0423b..f1094d3 100644 --- a/prolog/problems/lists_advanced/sum_2/sl.py +++ b/prolog/problems/lists_advanced/sum_2/sl.py @@ -1,5 +1,3 @@ -# coding=utf-8 - name = 'sum/2' slug = 'Izračunaj vsoto elementov v seznamu' @@ -10,4 +8,38 @@ description = '''\ Sum = 6. </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> +''', +} |