Commands.tx_spawn: def of bendvy-ecs-core@0.1.0.4
Import: import bendvy-ecs-core@0.1.0.4/commands.bend as Commands
Lines 67-75 of bendvy-ecs-core@0.1.0.4/commands.bend: https://jend.leeeet.dev/read.txt?path=bendvy-ecs-core@0.1.0.4/commands.bend&start_line=67&end_line=75

import Base
import bendvy-ecs-core@0.1.0.4/world.bend as W
import bendvy-ecs-core@0.1.0.4/transaction.bend as T

# IDs stay reserved on failure, matching the historical allocator policy.
# Reserve an entity handle now and stage activation/population for the barrier.
# Reserved is not yet live: ordinary component reads cannot observe it. The Type
# payload moves into the command; reservation refusal does not return that payload.
# Failure drops staged work and clears pending authority but does not rewind the
# allocator's reserved-ID progress. See examples/captured-query/schema.bend.
def tx_spawn(~S: Data,~C: Type,~R: Type,~E: Data,~P: Type,~populate: W.World<S,C,R,E> -> W.Handle<S> -> P -> W.World<S,C,R,E>,tx: T.Tx<W.World<S,C,R,E>,E>,payload: P) -> T.Tx<W.World<S,C,R,E>,E> & W.Reservation<S>:
  match tx:
    case T.Tx{world,undo,commands,events,trace}: spawn_join(~S,~C,~R,~E,~P,~populate,W.reserve_id(~S,~C,~R,~E,world),undo,commands,events,trace,payload)

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/commands.bend&name=spawn_join
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/transaction.bend&name=Tx
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/world.bend&name=Handle
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/world.bend&name=Reservation
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/world.bend&name=World
  https://jend.leeeet.dev/definition.txt?path=bendvy-ecs-core@0.1.0.4/world.bend&name=reserve_id