Explore graph reducers

[ZacSweers]

An idea from @swankjesse.

Part 1

If we have an assisted class like so

@Inject
class LoginScreen(
  apiService: ApiService, // injected
  @Assisted token: UserToken
) {

  @AssistedFactory
  interface Factory {
    fun create(token: UserToken): LoginScreen
  }
}

It should be possible expose a function of the same matching parameter + return type signature on the dependency graph

@DependencyGraph
interface AppGraph {
  fun createLoginScreen(token: String): LoginScreen
}

---

Part 2

We could also combine this with @GraphExtensions. These are factories of their own, so we could ostensibly reduce further. For example if a LoginScreen only exists in the extension, we could chain those assisted parameters all the way down

@DependencyGraph
interface AppGraph {
  fun createLoginScreen(token: UserToken): LoginScreen

  fun createLoggedInGraph(token: UserToken): LoggedInGraph
}

@GraphExtension
interface LoggedInGraph {
  fun createLoginScreen(token: UserToken): LoginScreen
}