1	import Base
2	import ./execution_resource_store.bend as Store
3	import ./change_tick.bend as Tick
4	
5	type Reader<-H:Type,-V:Data> is Type:
6	  Reader{get:H -> H & Store.Lookup<V>}
7	  UnsupportedReader{}
8	type Writer<-H:Type,-P:Type,-V:Data> is Type:
9	  Writer{read:Reader<H,V>,own:@-Out:Type -> H -> (P -> P & Out) -> H & Store.Edit<P,Out>,own_at:@-Out:Type -> H -> (Tick.Tick -> P -> P & Out) -> H & Store.Edit<P,Out>}
10	  UnsupportedWriter{}
11	def Reads(~V:Data,H:Type) -> Type:Reader<H,V>
12	def Writes(~P:Type,~V:Data,H:Type) -> Type:Writer<H,P,V>