Adding ScheduleGraph::contains_set

[urben1680]

Objective

The schedule graph can easily confirm whether a set is contained or not.

This helps me in my personal project where I write an extension trait for Schedule and I want to configure a specific set in its methods. The set in question has a run condition though and I don't want to add that condition to the same schedule as many times as the trait methods are called. Since the non-pub set is unknown to the schedule until then, a contains_set is sufficient.

It is probably trivial to add a method that returns an Option<NodeId> as well but as I personally don't need it I did not add that. If it is desired I can do so here though. It might be unneeded to have a contains_set then because one could check is_some on the returned id in that case.

An argument against that is that future changes may be easier if only a contains_set needs to be ported.

Solution

Added ScheduleGraph::contains_set.

Testing

I put the below showcase code into a temporary unit test and it worked. If wanted I add it as a test too but I did not see that other more somewhat complicated methods have tests

---

Showcase

#[derive(ScheduleLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct MySchedule;

#[derive(SystemSet, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct MySet;

let mut schedule = Schedule::new(MySchedule);
assert_eq!(schedule.graph().contains_set(MySet), false);
schedule.configure_sets(MySet);
assert_eq!(schedule.graph().contains_set(MySet), true);

[urben1680]

For funsies, this is my current workaround:

fn my_set_previously_unknown(schedule: &mut Schedule) -> bool {
    let (lower_bound_before, upper_bound_before) = schedule.graph().system_sets().size_hint();
    schedule.configure_sets(MySet);
    let (lower_bound_after, upper_bound_after) = schedule.graph().system_sets().size_hint();

    const EXPECT: &'static str = "ScheduleGraph::system_sets() expected to impl ExactSizeIterator";
    debug_assert_eq!(Some(lower_bound_before), upper_bound_before, "{EXPECT}");
    debug_assert_eq!(Some(lower_bound_after), upper_bound_after, "{EXPECT}");

    lower_bound_before < lower_bound_after
}