triggering process_event as an action in a transition table

[Trenton-Ruf]

I'm testing the example code:

using namespace sml;
return make_transition_table(
 *"s1"_s + event<my_event> / process_event(other_event{}) = "s2"_s,
  "s2"_s + event<other_event> = X
);

I am getting the error: error: 'process_event' was not declared in this scope

It works fine without the process_event:

using namespace sml;
return make_transition_table(
*"s1"_s + event<my_event> = "s2"_s,
"s2"_s + event<other_event> = X
);

Any Ideas?

Compiling with GCC 5.4.2 Building with PlatformIO for a teensy4.1

[kris-jusiak]

Hi @Trenton-Ruf

I think you meant to use process instead of process_event?

• https://github.com/boost-ext/sml/blob/master/example/defer_and_process.cpp

[Trenton-Ruf]

Alright! That works!

using namespace sml;
return make_transition_table(
 *"s1"_s + event<my_event> / process(other_event{}) = "s2"_s,
  "s2"_s + event<other_event> = X
);

Another question, can process be called within an action? I tried this:

// Action
const auto trigger = []{
sml::process(other_event{});
};

using namespace sml;
return make_transition_table(
 *"s1"_s + event<my_event> / trigger,
  "s2"_s + event<other_event> = X
);

It Compiles but does not process other_event.

[kris-jusiak]

Yeah, it's possible, you have to use process<events...> Something like

        ,  state + event<e1> / [this](sml::back::process<e2, e3> processEvent) -> void {
            processEvent(e2{});
            processEvent(e3{});
          }

That also requires to inject a process_even storage policy

  sml::sm<c, sml::process_queue<std::queue>> sm{};

Full example

• https://github.com/boost-ext/sml/blob/master/test/ft/actions_process.cpp#L171

[Trenton-Ruf]

Sick, Thanks a ton!

[tralamazza]

How can we pass a processEvent to lambda and have it be executed outside the process loop (e.g. a timer event)?

I know it's possible to do that using the full action signature [&](auto&& /*event*/, auto&& sm, auto&& deps, auto&& subs) { but that requires me to capture 4 references, which leads to dynamic memory allocation (not possible in my embedded project).

thanks.