MotionRuntime specification

This is the engineering specification for the MotionRuntime object.

Overview

A MotionRuntime’s primary responsibility is to write the output of streams to reactive properties.

We use the terms motion runtime and runtime interchangeably throughout the starmap.

MVP

Expose a concrete MotionRuntime class

public class MotionRuntime {
}

Expose a connect API

The implementation should subscribe to the stream and hold on to its subscription internally.

New values received from the subscribed stream should be written to the property.

class MotionRuntime {
  public func connect<T>(stream: MotionObservable<T>, to property: ReactiveProperty<T>)
}

Create private storage for subscriptions

An array is adequate because we currently have no mechanism for removing subscriptions once they are made.

class MotionRuntime {
  private var subscriptions: [Subscription] = []
}

Store all subscriptions

An array is adequate because we currently have no mechanism for removing subscriptions once they are made.

class MotionRuntime {
  func connect<T>(stream: MotionObservable<T>, to property: ReactiveProperty<T>) {
    subscriptions.append(stream.subscribe(next: { property.value = $0 }))
  }
}