diff options
Diffstat (limited to 'prolog/engine.py')
| -rw-r--r--[-rwxr-xr-x] | prolog/engine.py | 142 |
1 files changed, 69 insertions, 73 deletions
diff --git a/prolog/engine.py b/prolog/engine.py index 299d2eb..ec27e27 100755..100644 --- a/prolog/engine.py +++ b/prolog/engine.py @@ -1,7 +1,7 @@ #!/usr/bin/python3 from prolog.core import * -from prolog.util import * +import prolog.util class Atom(object): __slots__ = 'ref' @@ -80,29 +80,25 @@ class PrologEngine(object): # construct some predicates self.p = { - 'assertz': PL_predicate(b'assertz', 2, None), - 'erase': PL_predicate(b'erase', 1, None), - 'call_with_depth_limit': PL_predicate(b'call_with_depth_limit', 3, None), - 'call_with_time_limit': PL_predicate(b'call_with_time_limit', 2, None), - 'consult': PL_predicate(b'consult', 1, None), - 'findnsols': PL_predicate(b'findnsols', 4, None), - 'message_to_string': PL_predicate(b'message_to_string', 2, None), - 'read_term_from_atom': PL_predicate(b'read_term_from_atom', 3, None), - 'safe_goal': PL_predicate(b'safe_goal', 1, None), - 'set_prolog_stack': PL_predicate(b'set_prolog_stack', 2, None) + 'add_import_module/3': PL_predicate(b'add_import_module', 3, None), + 'assertz/1': PL_predicate(b'assertz', 1, None), + 'assertz/2': PL_predicate(b'assertz', 2, None), + 'erase/1': PL_predicate(b'erase', 1, None), + 'call_with_time_limit/2': PL_predicate(b'call_with_time_limit', 2, None), + 'consult/1': PL_predicate(b'consult', 1, None), + 'message_to_string/2': PL_predicate(b'message_to_string', 2, None), + 'read_term_from_atom/3': PL_predicate(b'read_term_from_atom', 3, None), + 'safe_goal/1': PL_predicate(b'safe_goal', 1, None), + 'set_prolog_stack/2': PL_predicate(b'set_prolog_stack', 2, None) } self.err_flags = PL_Q_NODEBUG|PL_Q_CATCH_EXCEPTION - # database of current asserts; each load gets a new index - self.refs = {} - self.max_index = 0 + # Increase memory limits. + self.call('set_prolog_stack/2', [Term('global'), Term('limit(2*10**9)')]) + self.call('set_prolog_stack/2', [Term('local'), Term('limit(2*10**9)')]) - # increase memory limits - self.call('set_prolog_stack', [Term('global'), Term('limit(2*10**9)')]) - self.call('set_prolog_stack', [Term('local'), Term('limit(2*10**9)')]) - - # discard messages from swipl library - self.load('message_hook(_, _, _). ') + # Discard messages from swipl library. + self.call('assertz/1', [Term('message_hook(_, _, _)')]) def exception(self, qid): ref = PL_exception(qid) @@ -113,7 +109,7 @@ class PrologEngine(object): if ex is not None: msg = Term() if PL_call_predicate(None, self.err_flags, - self.p['message_to_string'], Termv([ex, msg]).ref): + self.p['message_to_string/2'], Termv([ex, msg]).ref): raise Exception(str(msg)) raise Exception('Unknown error') finally: @@ -131,43 +127,7 @@ class PrologEngine(object): return True def consult(self, filename): - return self.call('consult', [Term(Atom(filename))]) - - def load(self, program, module=None): - tokens = tokenize(program) - refs = [] - try: - start = 0 - for idx in range(len(tokens)): - if tokens[idx].type != 'PERIOD' or idx - start <= 1: - continue - rule = stringify(tokens[start:idx]) - orig_rule = rule - start = idx + 1 - - if module is not None: - rule = module + ':(' + rule + ')' - ref = Term() - if self.call('assertz', [Term(rule), ref]): - refs.append(ref) - except Exception as ex: - # unload already loaded rules (hacky, mustfix, todo) - for ref in refs: - self.call('erase', [ref]) - raise Exception('Error loading program: {}\nBad rule: {}'.format(ex, orig_rule)) - - self.max_index += 1 - self.refs[self.max_index] = refs - return self.max_index - - def unload(self, index): - try: - for ref in self.refs[index]: - self.call('erase', [ref]) - del self.refs[index] - except Exception as ex: - # This should never happen. - sys.stderr.write(str(ex) + '\n') + return self.call('consult/1', [Term(Atom(filename))]) # Get up to [n] solutions to query [q]. def query(self, q, module=None, n=1): @@ -181,17 +141,17 @@ class PrologEngine(object): goal = Term() try: # Parse term and store variable names. - if not self.call('read_term_from_atom', [Term(Atom(q)), goal, options]): + if not self.call('read_term_from_atom/3', [Term(Atom(q)), goal, options]): raise Exception('Warning: Could not read term from {}\n'.format(q)) # Check if goal is safe with currently loaded rules. - if not self.call('safe_goal', [goal]): + if not self.call('safe_goal/1', [goal]): raise Exception('Warning: Unsafe goal: {}\n'.format(goal)) except Exception as ex: raise solutions = Term() goal_aux = Term('findnsols', [Term(n), goal, goal, solutions]) - qid = PL_open_query(None, self.err_flags, self.p['call_with_time_limit'], + qid = PL_open_query(None, self.err_flags, self.p['call_with_time_limit/2'], Termv([Term(0.01), goal_aux]).ref) result = [] @@ -215,15 +175,51 @@ class PrologEngine(object): return result -# Basic sanity check. -if __name__ == '__main__': - prolog = PrologEngine() - prolog.load('a(1). a(2). a(3).', 'test') - n = 1 - while True: - solution = prolog.query('a(X), a(Y), X\=Y', 'test', n=n) - if solution is None or len(solution) != n: - print('{} solutions found!'.format(n-1)) - break - print(solution[-1]) - n += 1 + # Loads the correct solution [code] to problem [pid]. + # TODO handle library loading. + def load_solution(self, pid, code): + module = 'solution{}'.format(pid) + for rule in prolog.util.split(code): + self.call('assertz/1', [Term('{}:({})'.format(module, rule))]) + + # Import the correct solution for problem [pid] into module for user [uid]. + def mark_solved(self, uid, pid): + m_user = 'user{}'.format(uid) + m_solution = 'solution{}'.format(pid) + return self.call('add_import_module/3', [Term(m_user), Term(m_solution), Term('end')]) + + # Test whether [code] gives the same answer to [query] as the correct + # solution. + def test(self, uid, pid, code, queries): + m_user = 'user{}'.format(uid) + m_solution = 'solution{}'.format(pid) + + # Find the correct answers. Code for [pid] should be loaded beforehand. + # TODO Memoize correct answers. + answers = [] + for query in queries: + result = self.query(query, m_solution) + if result is None or len(result) < 1 or 'X' not in result[0]: + raise Exception('Error finding correct answer to query "{}"'.format(query)) + answers.append(result[0]['X']) # TODO maybe we could check all vars? + + correct = True + refs = [] + try: + # Load the user program [code]. + for rule in prolog.util.split(code): + ref = Term() + if self.call('assertz/2', [Term('{}:({})'.format(m_user, rule)), ref]): + refs.append(ref) + + for i, query in enumerate(queries): + result = self.query(query, m_user) + correct &= (len(result) == 1 and result[0]['X'] == answers[i]) + except Exception as ex: + correct = False + finally: + # Unload all loaded rules. + for ref in refs: + self.call('erase/1', [ref]) + + return correct |