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 repl(hook):
lineno = 0
tokens = []
while True:
try:
log = pyson.Log(pyson.get_logger(__name__), 3)
if not tokens:
line = pyson.util.prompt("pyson.parser >>> ")
else:
line = pyson.util.prompt("pyson.parser ... ")
lineno += 1
tokens.extend(pyson.lexer.tokenize(pyson.StringSource("<stdin>", line), log, lineno))
while tokens:
token_stream = iter(tokens)
try:
agent = parse_agent("<stdin>", token_stream, log, frozenset())
except StopIteration:
log.throw()
break
else:
log.throw()
hook(agent)
tokens = list(token_stream)
except pyson.AggregatedError as error:
print(str(error), file=sys.stderr)
tokens = []
except KeyboardInterrupt:
print()
sys.exit(0)
def test_unexpected_eof(self):
src = pyson.StringSource("<test>", "a")
log = pyson.Log(pyson.get_logger(__name__), 3)
tokens = pyson.lexer.TokenStream(src, log)
with self.assertRaises(pyson.AggregatedError):
pyson.parser.parse(tokens, log, frozenset())
def main(source, lineno=1):
log = pyson.Log(pyson.get_logger(__name__), 3)
for tok in tokenize(source, log, lineno):
log.info("%s", tok.lexeme, loc=tok.loc)
log.throw()
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 test_unify_return_value(self):
src = pyson.StringSource("<test>", "+!p <- (X = 2) + 1 > 0.")
log = pyson.Log(pyson.get_logger(__name__), 3)
tokens = pyson.lexer.TokenStream(src, log)
with self.assertRaises(pyson.AggregatedError):
pyson.parser.parse(tokens, log, frozenset())
log.throw()
def test_rule_head_not_unifiable(self):
src = pyson.StringSource("<test>", "rule(X + 1) :- true.")
log = pyson.Log(pyson.get_logger(__name__), 3)
tokens = pyson.lexer.TokenStream(src, log)
pyson.parser.parse(tokens, log, frozenset())
with self.assertRaises(pyson.AggregatedError):
log.throw()
def test_formula_type(self):
src = pyson.StringSource("<test>", "+!plan <- ?true.")
log = pyson.Log(pyson.get_logger(__name__), 3)
tokens = pyson.lexer.TokenStream(src, log)
pyson.parser.parse(tokens, log, frozenset())
with self.assertRaises(pyson.AggregatedError):
log.throw()
def _build_agent(self, source, actions, agent_cls=Agent, name=None):
# Parse source.
log = pyson.Log(LOGGER, 3)
tokens = pyson.lexer.TokenStream(source, log)
ast_agent = pyson.parser.parse(tokens, log, frozenset(source.name))
log.throw()
return self.build_agent_from_ast(source, ast_agent, actions, agent_cls, name)
def main(source, hook):
log = pyson.Log(pyson.get_logger(__name__), 3)
tokens = pyson.lexer.TokenStream(source, log, 1)
agent = parse(source.name, tokens, log)
log.throw()
hook(agent)
def repl(agent, env, actions):
lineno = 0
tokens = []
env = Environment()
variables = {}
intention = Intention()
while True:
try:
log = pyson.Log(LOGGER, 3)
try:
if not tokens:
line = pyson.util.prompt("%s >>> " % agent.name)
else:
line = pyson.util.prompt("%s ... " % agent.name)
except KeyboardInterrupt:
print()
sys.exit(0)
lineno += 1
tokens.extend(
pyson.lexer.tokenize(pyson.StringSource("<stdin>", line), log,
lineno))
while tokens:
token_stream = iter(tokens)
try:
tok = next(token_stream)
tok, body = pyson.parser.parse_plan_body(
tok, token_stream, log)
except StopIteration:
log.throw()
break
else:
log.throw()
tokens = list(token_stream)
intention.instr = Instruction(noop)
body.accept(
BuildInstructionsVisitor(variables, actions,
intention.instr, log))
log.throw()
agent.intentions.append(collections.deque([intention]))
env.run_agent(agent)
dump_variables(variables, intention.scope)
except pyson.AggregatedError as error:
print(str(error), file=sys.stderr)
tokens = []
except pyson.PysonError as error:
LOGGER.error("%s", error)
tokens = []
def build_agent_from_ast(self, source, ast_agent, actions, agent_cls=Agent, name=None):
# This function is also called by the optimizer.
log = pyson.Log(LOGGER, 3)
agent = agent_cls(self, self._make_name(name or source.name))
# Add rules to agent prototype.
for ast_rule in ast_agent.rules:
variables = {}
head = ast_rule.head.accept(BuildTermVisitor(variables))
consequence = ast_rule.consequence.accept(BuildQueryVisitor(variables, actions, log))
agent.add_rule(Rule(head, consequence))
# Add plans to agent prototype.
for ast_plan in ast_agent.plans:
variables = {}
head = ast_plan.head.accept(BuildTermVisitor(variables))
if ast_plan.context:
context = ast_plan.context.accept(BuildQueryVisitor(variables, actions, log))
else:
context = TrueQuery()
body = Instruction(noop)
body.f = noop
if ast_plan.body:
ast_plan.body.accept(BuildInstructionsVisitor(variables, actions, body, log))
plan = Plan(ast_plan.trigger, ast_plan.goal_type, head, context, body)
agent.add_plan(plan)
# Add beliefs to agent prototype.
for ast_belief in ast_agent.beliefs:
belief = ast_belief.accept(BuildTermVisitor({}))
agent.call(pyson.Trigger.addition, pyson.GoalType.belief,
belief, Intention(), delayed=True)
# Call initial goals on agent prototype.
for ast_goal in ast_agent.goals:
term = ast_goal.atom.accept(BuildTermVisitor({}))
agent.call(pyson.Trigger.addition, pyson.GoalType.achievement,
term, Intention(), delayed=True)
# Report errors.
log.throw()
self.agents[agent.name] = agent
return ast_agent, agent
def _wait(agent, term, intention):
# Handle optional arguments.
args = [pyson.grounded(arg, intention.scope) for arg in term.args]
if len(args) == 2:
event, millis = args
else:
if pyson.is_number(args[0]):
millis = args[0]
event = None
else:
millis = None
event = args[0]
# Type checks.
if not (millis is None or pyson.is_number(millis)):
raise pyson.PysonError("expected timeout for .wait to be numeric")
if not (event is None or pyson.is_string(event)):
raise pyson.PysonError("expected event for .wait to be a string")
# Event.
if event is not None:
# Parse event.
if not event.endswith("."):
event += "."
log = pyson.Log(LOGGER, 1)
tokens = pyson.lexer.TokenStream(pyson.StringSource("<.wait>", event),
log)
tok, ast_event = pyson.parser.parse_event(tokens.next(), tokens, log)
if tok.lexeme != ".":
raise log.error(
"expected no further tokens after event for .wait, got: '%s'",
tok.lexeme,
loc=tok.loc)
# Build term.
event = ast_event.accept(pyson.runtime.BuildEventVisitor(log))
# Timeout.
if millis is None:
until = None
else:
until = agent.env.time() + millis / 1000
# Create waiter.
intention.waiter = pyson.runtime.Waiter(event=event, until=until)
yield
