Init system sketchesinit

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+The init system is the part of RNT responsible from taking a description of what a live system should look like and instantiating a system that matches this description, constructing and connecting different components as necessary. It is not a supervisor, that is, it is not responsible for maintaining the state of the system once it has been built, although it provides functionality that could support the implementation of a supervisor.
+
+More concretely, the role of the init system is to build a *system* out of a set of *components*. *Components* are the description of a building block of systems that can either require *services* from an existing component, extend an existing component and provide services to other components. A component that extends another component implicitly requires that component. Components, through this provision and requirement relationship, form a directed acyclic graph. Concretely, a component might look something like this:
+
+#+begin_src ocaml
+type service = ..
+
+type component =
+  { provides: service BatSet.t;
+    requires: service BatSet.t;
+    (* extends: extension list; *)
+    construct: (service, Handle.t) BatMap.t -> (Handle.t, Concepts.Condition.condition) result }
+
+
+
+module type SUBSYSTEM = struct
+  type t
+  val create : unit -> t
+  val destroy : t -> unit
+end
+
+module MySubsystem : SUBSYSTEM = struct
+
+end
+
+
+
+type ('a, 'b) service = ..
+
+type ('a, 'b) service += ServiceThatTakesAnInt
+let makeServiceThatTakesAnInt : int service = ServiceThatTakesAnInt
+
+type ('a, 'b) extension = ('a, 'b) service * ('a -> ('b, Concepts.Condition.condition) result)
+
+type component =
+  { provides: service;
+    extends: extension BatSet.t
+    extend: ()}
+
+let _ = Component.make
+	      ~provides:MySubsystem
+          ~extends:[extend Subsystem (fun h ->
+                        MySubsystem.make <><>)]
+
+let _ = Component.make
+	      ~requires:[SubsystemRegistry]
+          ~provides:[MySubsystem]
+          ~mount:(fun h ->
+            let myself = MySubstystem.make <><> in
+            SubssystemRegistry.register myself;
+            myself)
+          ~unmount:(fun h myself ->
+            Lifecycle.destroy myself)
+
+(* options:
+   - object destroy itself on unmount through lifecycles
+     - would require us to be able to notify the owner, which would mean we have to know who the owner is
+ ,*)
+
+
+
+type component =
+  { ex}
+#+end_src