def add_belief(self, term, scope):
term = term.grounded(scope)
if term.functor is None:
raise PysonError("expected belief literal")
self.beliefs[(term.functor, len(term.args))].add(term)
def execute(self, agent, intention):
# Boolean constants.
term = pyson.evaluate(self.term, intention.scope)
if term is True:
yield
return
elif term is False:
return
try:
group = term.literal_group()
except AttributeError:
raise PysonError(
"expected boolean or literal in query context, got: '%s'" %
term)
# Query on the belief base.
for belief in agent.beliefs[group]:
for _ in pyson.unify_annotated(term, belief, intention.scope,
intention.stack):
yield
choicepoint = object()
# Follow rules.
for rule in agent.rules[group]:
rule = copy.deepcopy(rule)
intention.stack.append(choicepoint)
if pyson.unify(term, rule.head, intention.scope, intention.stack):
for _ in rule.query.execute(agent, intention):
yield
pyson.reroll(intention.scope, intention.stack, choicepoint)
def call(self, trigger, goal_type, term, calling_intention, delayed=False):
if goal_type == pyson.GoalType.belief:
if trigger == pyson.Trigger.addition:
self.add_belief(term, calling_intention.scope)
else:
found = self.remove_belief(term, calling_intention)
if not found:
return True
frozen = pyson.freeze(term, calling_intention.scope, {})
if not isinstance(frozen, pyson.Literal):
raise PysonError("expected literal")
applicable_plans = self.plans[(trigger, goal_type, frozen.functor,
len(frozen.args))]
choicepoint = object()
intention = Intention()
for plan in applicable_plans:
for _ in pyson.unify_annotated(plan.head, frozen, intention.scope,
intention.stack):
for _ in plan.context.execute(self, intention):
intention.head_term = frozen
intention.instr = plan.body
intention.calling_term = term
if not delayed and self.intentions:
for intention_stack in self.intentions:
if intention_stack[-1] == calling_intention:
intention_stack.append(intention)
return True
new_intention_stack = collections.deque()
new_intention_stack.append(intention)
self.intentions.append(new_intention_stack)
return True
if goal_type == pyson.GoalType.achievement:
raise PysonError("no applicable plan for %s%s%s/%d" %
(trigger.value, goal_type.value, frozen.functor,
len(frozen.args)))
elif goal_type == pyson.GoalType.test:
return self.test_belief(term, calling_intention)
return True
def step(self):
while self.intentions and not self.intentions[0]:
self.intentions.popleft()
for intention_stack in self.intentions:
intention = intention_stack[-1]
# Wait until.
if intention.wait_until:
if intention.wait_until < self.env.time():
intention.wait_until = None
else:
continue
break
else:
return False
instr = intention.instr
if not instr:
intention_stack.pop()
if not intention_stack:
self.intentions.remove(intention_stack)
elif intention.calling_term:
frozen = intention.head_term.freeze(intention.scope, {})
calling_intention = intention_stack[-1]
if not pyson.unify(intention.calling_term, frozen,
calling_intention.scope,
calling_intention.stack):
raise RuntimeError("back unification failed")
return True
try:
if instr.f(self, intention):
intention.instr = instr.success
else:
intention.instr = instr.failure
if not intention.instr:
raise PysonError("plan failure")
except PysonError as err:
log = pyson.Log(LOGGER)
raise log.error("%s @ %s",
err,
instr.f,
loc=instr.loc,
extra_locs=instr.extra_locs)
except:
log = pyson.Log(LOGGER)
raise log.exception("python exception @ %s",
instr.f,
loc=instr.loc,
extra_locs=instr.extra_locs)
return True
def test_belief(self, term, intention):
term = pyson.evaluate(term, intention.scope)
if not isinstance(term, pyson.Literal):
raise PysonError("expected belief literal, got: '%s'" % term)
query = TermQuery(term)
try:
next(query.execute(self, intention))
return True
except StopIteration:
return False
def step(self):
while self.intentions and not self.intentions[0]:
self.intentions.popleft()
for intention_stack in self.intentions:
intention = intention_stack[-1]
# Suspended / waiting.
if intention.waiter is not None:
if intention.waiter.poll(self.env):
intention.waiter = None
else:
continue
break
else:
return False
instr = intention.instr
if not instr:
intention_stack.pop()
if not intention_stack:
self.intentions.remove(intention_stack)
elif intention.calling_term:
frozen = intention.head_term.freeze(intention.scope, {})
calling_intention = intention_stack[-1]
if not pyson.unify(intention.calling_term, frozen, calling_intention.scope, calling_intention.stack):
raise RuntimeError("back unification failed")
return True
try:
if instr.f(self, intention):
intention.instr = instr.success
else:
intention.instr = instr.failure
if not intention.instr:
raise PysonError("plan failure")
except PysonError as err:
log = pyson.Log(LOGGER)
raise log.error("%s", err, loc=instr.loc, extra_locs=instr.extra_locs)
except Exception as err:
log = pyson.Log(LOGGER)
raise log.exception("agent %r raised python exception: %r", self.name, err,
loc=instr.loc, extra_locs=instr.extra_locs)
return True
def remove_belief(self, term, intention):
term = pyson.evaluate(term, intention.scope)
try:
group = term.literal_group()
except AttributeError:
raise PysonError("expected belief literal, got: '%s'" % term)
choicepoint = object()
relevant_beliefs = self.beliefs[group]
for belief in relevant_beliefs:
intention.stack.append(choicepoint)
if pyson.unify(term, belief, intention.scope, intention.stack):
relevant_beliefs.remove(belief)
return True
pyson.reroll(intention.scope, intention.stack, choicepoint)
return False