1	import Base
2	
3	type Outcome<-Value:Data,-Error:Data> is Data:
4	  Saved{value:Value}
5	  RefusedPending{}
6	  Refused{error:Error}
7	
8	# Framework boundary. The ordinary adapter supplies the closed owner inventory,
9	# not deferred history or a caller's estimate of outstanding work.
10	def checked(~Actual:Type,~Value:Data,~Error:Data,~project:Actual -> Actual & Outcome<Value,Error>,result:Actual & Bool) -> Actual & Outcome<Value,Error>:
11	  match result:
12	    case (actual,True{}):(actual,RefusedPending{})
13	    case (actual,False{}):project(actual)
14	def save(~Actual:Type,~Value:Data,~Error:Data,~pending:Actual -> Actual & Bool,~project:Actual -> Actual & Outcome<Value,Error>,actual:Actual) -> Actual & Outcome<Value,Error>:
15	  checked(~Actual,~Value,~Error,~project,pending(actual))