1	import Base
2	import ./schedule.bend as Sch
3	import ./world.bend as W
4	import ./system.bend as Sys
5	# Declaration lowering owns fixed group order; closed callbacks retain failure outcomes.
6	# Detached ordinary marker schedule name; phase lowering is fixed by the library.
7	type Declaration<-S:Data> is Data: Declaration{name:String}
8	# Declare the marker schedule label without building or executing handlers.
9	def declare(~S:Data,name:String) -> Declaration<S>:Declaration{name}
10	def phase_name(id:U32) -> String:
11	  match id:
12	    case 1:"apply"
13	    case 2:"exit"
14	    case 3:"transition"
15	    case _:"enter"
16	# Fixed sequence: structural barrier, then apply, exit, transition and enter
17	# system groups with their phase labels and condition slot zero.
18	def steps() -> List<&2,Sch.Step>:[Sch.Barrier{},Sch.Phase{phase_name(1)},Sch.System{1,0},Sch.Phase{phase_name(2)},Sch.System{2,0},Sch.Phase{phase_name(3)},Sch.System{3,0},Sch.Phase{phase_name(4)},Sch.System{4,0}]
19	# Build the fixed four-group schedule retaining actual H owners. Group ids 1..4
20	# are internal dispatch slots, not newly registered gameplay system identities.
21	def install(~S:Data,~C:Type,~R:Type,~E:Data,~H:Type,~Error:Data,declaration:Declaration<S>,namespace:U32,owners:H) -> Sch.Build<S,C,R,E,H>:
22	  match declaration:
23	    case Declaration{name}:Sch.build(~S,~C,~R,~E,~H,namespace,name,steps(),[1,2,3,4],owners)
24	# Advanced fixed-group router: ids 1/2/3 call apply/exit/transition; the remaining
25	# case calls enter. Use with steps(), not arbitrary ids assumed validated here.
26	# Closed callbacks must return actual owners/World and their failure outcome.
27	def dispatch(~S:Data,~C:Type,~R:Type,~E:Data,~H:Type,~Error:Data,~apply:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~exit:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~transition:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~enter:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,owners:H,world:W.World<S,C,R,E>,id:U32) -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>:
28	  match id:
29	    case 1:apply(owners,world)
30	    case 2:exit(owners,world)
31	    case 3:transition(owners,world)
32	    case _:enter(owners,world)
33	# Fixed marker group condition returns World unchanged and True.
34	def condition(~S:Data,~C:Type,~R:Type,~E:Data,world:W.World<S,C,R,E>,_:U32) -> W.World<S,C,R,E> & Bool:(world,True{})
35	# Run the fixed schedule after namespace admission, preserving H and World in
36	# all results. Stop on first failed callback; earlier successful transactions are
37	# not one marker-wide rollback. Explicit initial barrier precedes group dispatch.
38	# See docs/parity/handlers.md for the higher-level transition-marker contract.
39	def run(~S:Data,~C:Type,~R:Type,~E:Data,~H:Type,~Error:Data,~apply:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~exit:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~transition:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,~enter:H -> W.World<S,C,R,E> -> H & Sys.Outcome<W.World<S,C,R,E>,Error,Unit>,schedule:Sch.Schedule<S,C,R,E,H>,world:W.World<S,C,R,E>) -> Sch.RunResult<S,C,R,E,H,Error>:Sch.run(~S,~C,~R,~E,~H,~Error,~dispatch(~S,~C,~R,~E,~H,~Error,~apply,~exit,~transition,~enter),~condition(~S,~C,~R,~E),schedule,world)