1	import Base
2	import ./entity_key.bend as Key
3	import ./world.bend as W
4	import ./decode_data.bend as D
5	import ./decode_construction.bend as Constructor
6	import ./snapshot_data.bend as Snapshot
7	
8	type Binding<S:Data> is Data:
9	  Binding{saved:Key.Key,target:W.Handle<S>}
10	type Change<S:Data> is Data:
11	  Removed{target:W.Handle<S>,name:String}
12	  Despawned{target:W.Handle<S>}
13	  Spawned{target:W.Handle<S>}
14	type Position is Data:
15	  Component{saved:Key.Key}
16	  Resource{}
17	type Error<Custom:Data> is Data:
18	  InvalidSnapshot{path:String}
19	  UnsupportedVersion{version:D.Raw}
20	  DuplicateEntity{saved:Key.Key}
21	  UnknownComponent{saved:Key.Key,name:String}
22	  UnknownResource{name:String}
23	  InvalidComponent{saved:Key.Key,name:String,error:Constructor.Error<Custom>}
24	  InvalidResource{name:String,error:Constructor.Error<Custom>}
25	  UnvalidatedDescriptor{name:String}
26	  Capacity{nextEntity:U32}
27	type Dispatch<Custom:Data> is Data:
28	  Unhandled{}
29	  Staged{}
30	  Rejected{error:Constructor.Error<Custom>}
31	type Prepared<State:Type,Custom:Data> is Type:
32	  Ready{state:State,snapshot:Snapshot.Snapshot}
33	  Refused{state:State,input:Snapshot.Snapshot,error:Error<Custom>}
34	def lookup_choose(~S:Data,equal:Bool,target:W.Handle<S>,next:Unit -> Maybe<&2,W.Handle<S>>) -> Maybe<&2,W.Handle<S>>:
35	  match equal:
36	    case True{}:Some{target}
37	    case False{}:next(Unit{})
38	def lookup(~S:Data,+saved:Key.Key,bindings:List<&2,Binding<S>>) -> Maybe<&2,W.Handle<S>>:
39	  match bindings:
40	    case []:None{}
41	    case Binding{+key,+target} <> rest:
42	      lookup_choose(~S,Key.equal(saved,key),target,_ => lookup(~S,saved,rest))