diff options
Diffstat (limited to 'prolog/problems/lists/divide_3/common.py')
| -rw-r--r-- | prolog/problems/lists/divide_3/common.py | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/prolog/problems/lists/divide_3/common.py b/prolog/problems/lists/divide_3/common.py index 544dbc4..34b7fe9 100644 --- a/prolog/problems/lists/divide_3/common.py +++ b/prolog/problems/lists/divide_3/common.py @@ -8,7 +8,7 @@ from server.hints import Hint, HintPopup import server.problems id = 115 -number = 8 +number = 7 visible = True facts = None @@ -26,8 +26,10 @@ hint_type = { 'base_case': Hint('base_case'), 'recursive_case': Hint('recursive_case'), 'timeout': Hint('timeout'), - '[]_should_not_succeed': Hint('[]_should_not_succeed'), - 'list_returned': Hint('list_returned'), + 'base_case_arbitrary': Hint('base_case_arbitrary'), + 'second_base_case_missing': Hint('second_base_case_missing'), + 'unsuccessful_conc_use': Hint('unsuccessful_conc_use'), + 'forcing_result_onto_recursion': Hint('forcing_result_onto_recursion'), } test_cases = [ @@ -76,28 +78,44 @@ def hint(code, aux_code): return [{'id': 'eq_instead_of_equ_markup', 'start': m[0], 'end': m[1]} for m in marks] + \ [{'id': 'eq_instead_of_equ'}] + # general unsuccessful use of conc (not appropriate for this exercise) + if prolog.util.Token('NAME', 'conc') in tokens: + return [{'id': 'unsuccessful_conc_use'}] + # recursion is getting bigger and bigger - # succeeds when asked to return the last element of an empty list - if prolog.engine.ask_truthTO(engine_id, 'last_elem([], _)'): - return [{'id': '[]_should_not_succeed'}] - # returns a list, not an element as required - if prolog.engine.ask_one(engine_id, 'last_elem([qQ], [qQ])'): # 'last_elem([qQ], X), is_list(X)' with ask_one? - return [{'id': 'list_returned'}] + # forcing result onto recursion; case of divide(T, [H1|L1], [H2|L2]) + if not prolog.engine.ask_truthTO(engine_id, 'divide([a,b,c], _, _)') and \ + prolog.engine.ask_truthTO(engine_id, + 'asserta( divide([cob], [yowza,cob], [brix]) ), divide([yowza,brix,cob], [yowza,cob], [brix]), retract( divide([cob], [yowza,cob], [brix]) )'): + return [{'id': 'forcing_result_onto_recursion'}] + + # base case succeeds with arbitrary result + if prolog.engine.ask_truthTO(engine_id, 'divide([], L1, L2), (var(L1) ; var(L2))') or \ + prolog.engine.ask_truthTO(engine_id, 'divide([q], L1, L2), (var(L1) ; var(L2))') or \ + prolog.engine.ask_truthTO(engine_id, 'divide([q], [q|L1], L2), (var(L1) ; var(L2))'): + return [{'id': 'base_case_arbitrary'}] + + # one base case ok, the other one is missing (or bad) + # only trigger when recursion also works, because that makes more sense to the student + # than immediately telling him or her that there is another base case missing + if prolog.engine.ask_truthTO(engine_id, + 'divide([a,b], [a], [b]), \+ divide([a,b,c], [a,c], [b]) ; \+ divide([a,b], [a], [b]), divide([a,b,c], [a,c], [b])'): + return [{'id': 'second_base_case_missing'}] # missing/failed base case - if not prolog.engine.ask_truthTO(engine_id, 'last_elem([], [], [])'): + if not prolog.engine.ask_truthTO(engine_id, 'divide([], [], [])'): return [{'id': 'base_case'}] # target predicate seems to always be false - if not prolog.engine.ask_truthTO(engine_id, 'last_elem(_, _)') and \ - not prolog.engine.ask_truthTO(engine_id, 'last_elem([_,_,_,_,_,_], _)'): + if not prolog.engine.ask_truthTO(engine_id, 'divide([_,_,_,_,_], _, _)') and \ + not prolog.engine.ask_truthTO(engine_id, 'divide([_,_,_,_,_,_], _, _)'): return [{'id': 'predicate_always_false'}] - # base case works, the recursive doesn't (but it doesn't timeout) + # base cases work, 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, 'last_elem([qa,qb,qQ,qc], qc)'): + if not prolog.engine.ask_truth(engine_id, 'divide([qa,qb,qc,qd], [qa,qc], [qb,qd])'): return [{'id': 'recursive_case'}] except socket.timeout as ex: |