Adjusting access to utils for federated execution after fed-gen is done

[hokeun]

After fed-gen is done, the generated .lf files from a federated LF program will be the main reactors, which is currently generated as App class rather than FederatedApp class.
However, inside the network sender body (reaction body), this.util.sendRTITimedMessage will be called in the main reactor. This is currently not possible since App class doesn't implement sendRTIMessage or sendRTITimedMessage like this.

    protected sendRTIMessage<T extends Present>(data: T, destFederateID: number, destPortID: number) {
        throw new Error("Cannot call sendRTIMessage from an App. sendRTIMessage may be called only from a FederatedApp");
    }

    protected sendRTITimedMessage<T extends Present>(data: T, destFederateID: number, destPortID: number) {
        throw new Error("Cannot call sendRTIMessage from an App. sendRTIMessage may be called only from a FederatedApp");
    }

Possible solutions:

1. Somehow we distinguish a reactor to be generated as FederatedApp and a reactor to be generated as App.
2. Allow sendRTITimedMessage to be called inside App
3. Other suggestions? (@lhstrh)

[lhstrh]

@byeong-gil: I think this may be part-way addressed? I believe we do use the FederatedApp class, but there are still methods in the App class that belong in the FederatedApp class.

[byeonggiljun]

@byeong-gil: I think this may be part-way addressed? I believe we do use the FederatedApp class, but there are still methods in the App class that belong in the FederatedApp class.

Yes, I think so. We do use the FederatedApp class and the access of util functions like sendRTITImedMessage is handled properly.

[lhstrh]

But aren't they defined in App (vs. FederatedApp)?

[byeonggiljun]

Yes, they are. Should we define those things in FederatedApp?

Actually, those functions are defined in util as below and are overridden here. I couldn't imagine how we can get rid of them from the util class.

reactor-ts/src/core/reactor.ts

Lines 1916 to 1923 in bb9b0ea

	public sendRTITimedMessage<T>(
	data: T,
	destFederateID: number,
	destPortID: number,
	time: TimeValue | undefined
	): void {
	this.app.sendRTITimedMessage(data, destFederateID, destPortID, time);
	}

Additionally, the below function is able to be removed simply. It is not overridden and just sends an error.

reactor-ts/src/core/reactor.ts

Lines 2085 to 2094 in bb9b0ea

	protected sendRTITimedMessage<T>(
	data: T,
	destFederateID: number,
	destPortID: number,
	time: TimeValue | undefined
	): void {
	throw new Error(
	"Cannot call sendRTIMessage from an App. sendRTIMessage may be called only from a FederatedApp"
	);
	}

[lhstrh]

I don't think that UtilityFunctions has to be defined anonymously. We can define it in some other file and have a FederateUtilityFunctions extends UtilityFunctions that includes all the additional communication methods. We'll just instantiate it in FederatedApp (which, in hindsight, I think should actually just be called Federate).

[byeonggiljun]

I got it. I'll make a PR to address it and another PR or issue for renaming (e.g. FederatedApp -> Federate, TimedMessage -> TaggedMessage...).