roadside lamp

1layer over ./Record.obend
2edition ObjectiveBend 1
3import ./Abi.obend as Abi
4import ./List.obend as Lists
5import ./Document.obend as Document
6import ./Form.obend as Form
7import ./Plan.obend as Plans
8import ./World.obend as World
9import ./Card.obend as Card
10import ./Scenes.obend as Scenes
11import ./Relation.obend as Relations
12import ./Rows.obend as Rows
13import ./Text.obend as Text
14# The lantern's body, over RECORD (docs/METAPHYSICS.md §7.5; SEEDING §4): a record made by a door
15# (`door`, fixed). As its kind finishes it, it places a rule on that door under its maker (`made`):
16# when the door's `open` mark comes, the door casts `delvetalk <lantern> light`, and the lantern is
17# lit, once (its mark `lit`). Only that rule lights it, and only while the door is open: a hand's
18# `light`, or another's rule on the door, is refused by name.
19type State = Super.State
20form light:
21form arm:
22form write:
23  text: text 1..280
24form lines:
25  from: natural 0..1000000000
26form door:
27  label: text 1..32
28  to: text 1..128
29form undoor:
30  label: text 1..32
31def write(state: State, input: WriteInput, context: Abi.Context) -> Activity<Nat>:
32  Super.write(state, {text: input.text}, context)
33def lines(state: State, input: LinesInput, context: Abi.Context) -> Activity<Card.Replied>:
34  Super.lines(state, {from: input.from}, context)
35def door(state: State, input: DoorInput, context: Abi.Context) -> Activity<Card.Replied>:
36  Super.door(state, {label: input.label, to: input.to}, context)
37def undoor(state: State, input: UndoorInput, context: Abi.Context) -> Activity<Card.Replied>:
38  Super.undoor(state, {label: input.label}, context)
39def actions(state: State, context: Abi.Context) -> Lists.List<String>:
40  Lists.concat(if context.principal == state.owner then Text.words("light lines door undoor") else Text.words("light lines"), if context.principal == state.maker then Text.words("arm") else Text.words(""))
41def methods() -> Lists.List<String>:
42  Text.words("~made ~act")
43def watched(state: State) -> String:
44  Super.field(state, "door")
45def made(state: State, input: {}, context: Abi.Context) -> Activity<Bool>:
46  if context.caller != state.kind then false else placing(state, context)
47def placing(state: State, context: Abi.Context) -> Activity<Bool>:
48  match world.rule({object: {world: context.world, object: watched(state)}, name: Text.identifier(context.object), when: "\"open\" in new.marks.name and not \"open\" in old.marks.name", then: "delvetalk {context.object} light"}):
49    case placed(_): Super.armedNow(state, context)
50    case refused(r): Super.unarmed(state, watched(state), r.clause, r.reading, context)
51# Its maker places its rule again (taken off first, if it stood).
52def arm(state: State, context: Abi.Context) -> Activity<Bool>:
53  if context.principal != state.maker then Super.armRefused(state, context) else rearming(state, context)
54def rearming(state: State, context: Abi.Context) -> Activity<Bool>:
55  match world.unrule({object: {world: context.world, object: watched(state)}, name: Text.identifier(context.object)}):
56    case _: placing(state, context)
57# Only its maker's rule on its door lights it, and only once the door is open.
58def light(state: State, context: Abi.Context) -> Activity<Bool>:
59  if Super.ruledFrom(state, watched(state), context) == false then unlit(state, context) else opened(state, context)
60def opened(state: State, context: Abi.Context) -> Activity<Bool>:
61  match world.viewField::<Relations.Relation<Rows.Mark>>({object: {world: context.world, object: watched(state)}, field: "marks"}):
62    case viewed(v): if Relations.has(v.state, {name: "open"}) then Super.mark(state, "lit", context) else unlit(state, context)
63    case _: unlit(state, context)
64def unlit(state: State, context: Abi.Context) -> Activity<Bool>:
65  Card.refusing(false, {clause: "ruled", reading: "it lights when {watched(state)} opens: delvetalk {watched(state)} knock"}, context)
66def headLine(state: State, context: Abi.Context, id: String) -> Document.Document:
67  let name = if state.head == "" then "A LANTERN" else state.head
68  let lit = if Super.marked(state, "lit") then "lit" else "dark"
69  Document.text("{name}, by {watched(state)}: {lit}; it lights when {watched(state)} opens.\n{Super.inactiveLine(state, id)}")

--- the entry module
+++ this layer
@@ -25 +25 @@
-  from: natural 0..1000000000
+  from: natural 1..1000000000

set it in type, all 69 lines