Commit 14d28be3 authored by Paul Sokolovsky's avatar Paul Sokolovsky
Browse files

gen.send(): Throw StopIteration. Also, explicitly shutdown finished gen.

Otherwise, some generator statements still may be spuriously executed on
subsequent calls to next()/send().
parent addf60b2
......@@ -73,8 +73,11 @@ mp_obj_t gen_instance_getiter(mp_obj_t self_in) {
return self_in;
}
static mp_obj_t gen_send(mp_obj_t self_in, mp_obj_t send_value) {
static mp_obj_t gen_next_send(mp_obj_t self_in, mp_obj_t send_value) {
mp_obj_gen_instance_t *self = self_in;
if (self->ip == 0) {
return mp_const_stop_iteration;
}
if (self->sp == self->state - 1) {
if (send_value != mp_const_none) {
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_TypeError, "can't send non-None value to a just-started generator"));
......@@ -86,6 +89,12 @@ static mp_obj_t gen_send(mp_obj_t self_in, mp_obj_t send_value) {
if (yield) {
return *self->sp;
} else {
// Explicitly mark generator as completed. If we don't do this,
// subsequent next() may re-execute statements after last yield
// again and again, leading to side effects.
// TODO: check how return with value behaves under such conditions
// in CPython.
self->ip = 0;
if (*self->sp == mp_const_none) {
return mp_const_stop_iteration;
} else {
......@@ -94,14 +103,22 @@ static mp_obj_t gen_send(mp_obj_t self_in, mp_obj_t send_value) {
}
}
}
static MP_DEFINE_CONST_FUN_OBJ_2(gen_send_obj, gen_send);
mp_obj_t gen_instance_iternext(mp_obj_t self_in) {
return gen_send(self_in, mp_const_none);
return gen_next_send(self_in, mp_const_none);
}
static mp_obj_t gen_instance_send(mp_obj_t self_in, mp_obj_t send_value) {
mp_obj_t ret = gen_next_send(self_in, send_value);
if (ret == mp_const_stop_iteration) {
nlr_jump(mp_obj_new_exception(MP_QSTR_StopIteration));
}
return ret;
}
static MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_send_obj, gen_instance_send);
static const mp_method_t gen_type_methods[] = {
{ "send", &gen_send_obj },
{ "send", &gen_instance_send_obj },
{ NULL, NULL }, // end-of-list sentinel
};
......
......@@ -13,3 +13,25 @@ except TypeError:
print(g.send(None))
print(g.send(100))
print(g.send(200))
def f2():
print("entering")
for i in range(3):
print(i)
yield
print("returning 1")
print("returning 2")
g = f2()
g.send(None)
g.send(1)
g.send(1)
try:
g.send(1)
except StopIteration:
print("caught")
try:
g.send(1)
except StopIteration:
print("caught")
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