transporters

kiln-core/CLAUDE.md

@@ -20,7 +20,7 @@ The core types that were formerly monolithic in `game.rs` are now split into foc
 **`kiln-core/src/archetype.rs`** — element taxonomy:
 - `Archetype` (`Copy`, `PartialEq`, `Hash`) — enum of named element types: `Empty`, `Wall`, `Crate`, `HCrate`, `VCrate`, `Builtin(Builtin, &'static str)`, `ErrorBlock`. Each variant provides `behavior()`, `name()` (used in map files), and `default_glyph()`. `Crate` pushable any direction (CP437 ■, char 254); `HCrate`/`VCrate` pushable east/west (↔, char 29) / north/south (↕, char 18) only. `ErrorBlock` is a sentinel for unknown archetype names (yellow `?` on red). `TryFrom<&str>` checks the `Builtin` registry first (via `Builtin::from_name`), then the hard-coded terrain names; unrecognized names return `Err` (the map loader substitutes `ErrorBlock`).
 - `Builtin` (`Copy`, `PartialEq`, `Hash`) — the family enum for all script-backed archetypes: `Gem`, `Heart`, `Pusher`, `Spinner`, `Key`. Generated by the `builtins!` macro (see below) along with all its methods. `Archetype::Builtin(family, alias)` carries both the family (selects the behavior and script source) and the specific alias matched during parsing (e.g. `"pusher_north"` or `"spinner_cw"`); the alias drives the per-alias glyph, the `BUILTIN_<alias>` tag on the expanded object, and the compile-cache key.
-- `macro_rules! builtins!` — the declarative registry for script-backed archetypes. Each entry: `Variant => ["alias" => tile, …] { behavior, fg, bg, script: include_str!(…) }`. The macro generates `enum Builtin { … }` and `impl Builtin { from_name, behavior, default_glyph_for, script }`. **To add a new builtin**: add one entry here + write `src/scripts/<name>.rhai`. No other code changes are needed — `TryFrom<&str>`, `behavior()`, `name()`, `default_glyph()`, the expansion pass, and the save round-trip all derive from the macro output. Current entries: `Gem` (`"gem"` → tile 4, blue ♦, solid + pushable + grab), `Heart` (`"heart"` → tile 3, red ♥, solid + pushable + grab — restores 1 health on grab), `Pusher` (`"pusher_north"` → 30, `"pusher_south"` → 31, `"pusher_east"` → 16, `"pusher_west"` → 17; gray arrow tiles, solid + unpushable), `Spinner` (`"spinner_cw"` → 47 `/`, `"spinner_ccw"` → 92 `\`; gray, solid + unpushable). All aliases in a family share one Rhai script; the script reads `me.has_tag("BUILTIN_<alias>")` to determine per-instance direction/chirality.
+- `macro_rules! builtins!` — the declarative registry for script-backed archetypes. Each entry: `Variant => ["alias" => tile, …] { behavior, fg, bg, script: include_str!(…) }`. The macro generates `enum Builtin { … }` and `impl Builtin { from_name, behavior, default_glyph_for, script }`. **To add a new builtin**: add one entry here + write `src/scripts/<name>.rhai`. No other code changes are needed — `TryFrom<&str>`, `behavior()`, `name()`, `default_glyph()`, the expansion pass, and the save round-trip all derive from the macro output. Current entries: `Gem` (`"gem"` → tile 4, blue ♦, solid + pushable + grab), `Heart` (`"heart"` → tile 3, red ♥, solid + pushable + grab — restores 1 health on grab), `Pusher` (`"pusher_north"` → 30, `"pusher_south"` → 31, `"pusher_east"` → 16, `"pusher_west"` → 17; gray arrow tiles, solid + unpushable), `Spinner` (`"spinner_cw"` → 47 `/`, `"spinner_ccw"` → 92 `\`; gray, solid + unpushable), `Transporter` (`"transporter_north|south|east|west"` → 94/118/41/40 `^`/`v`/`)`/`(`; cyan, solid + **see-through** (`opaque: false`) + unpushable — animates a 4-frame loop and teleports whatever bumps it from the front, either past it or out of a paired opposite-facing transporter). All aliases in a family share one Rhai script; the script reads `me.has_tag("BUILTIN_<alias>")` to determine per-instance direction/chirality.
 
 **`kiln-core/src/builtin_scripts.rs`** — tag helpers for script-backed archetypes (`pub(crate)`):
 - `BUILTIN_TAG_PREFIX` (`"BUILTIN_"`), `builtin_tag(arch) -> String`, `archetype_from_builtin_tag(tag) -> Option<Archetype>` — the tag convention. `expand_builtin_archetypes` tags each expanded object with `BUILTIN_<alias>` (e.g. `"BUILTIN_pusher_east"`) and also uses this string as the object's `script_name` compile-cache key (so each alias gets its own cached AST, though the Rhai source is the same for all aliases in a family). The script reads its tag to determine per-instance direction. `map_file::save` uses `archetype_from_builtin_tag` to collapse the object back into its archetype keyword so maps round-trip. The script sources and behavior definitions now live in `archetype.rs` via the `builtins!` macro (via `include_str!` of `scripts/*.rhai`); this file has only the three tag helpers.
@@ -92,7 +92,7 @@ The core types that were formerly monolithic in `game.rs` are now split into foc
 - Lifecycle hooks, each taking `me` (an `ObjectInfo`) and `state` (a `ScriptState`) before any hook-specific arg: `init(me, state)`, `tick(me, state, dt)`, `bump(me, state, id)` (the bumper's `ObjectId`, or `-1` for the player), and `grab(me, state)` (fired when the player walks onto a `grab` thing — the only grab trigger). All optional — detected via `AST::iter_functions()` by name **and arity** (2/3/3/2). Driven by `run_init(state)` / `run_tick(state, dt)` / `run_bump(state, id, bumper)` / `run_grab(state, id)`, all funneling through `run_hook_on_one`: it builds a fresh `ObjectInfo` for the object, pushes `[me, state, (arg)]`, and calls the hook tagged with the object's id. After the call — **whether or not the hook is defined** — it always drains the object's queue, so a delay still advances on an object that has no `tick`. Runtime errors go to the error sink (drained to the log), not fatal.
 - `run_send(state, id, fn_name, arg)` — calls an arbitrary named function on an object (backs the `send()` action and scroll-choice dispatch). Picks the param list by the function's arity: 3 → `(me, state, arg)`, 2 → `(me, state)`, 1 → `(arg)`, 0 → `()`; a missing arg is `Dynamic::UNIT`. Errors if no function of that name exists.
 - **Reads** are methods/getters on the `api` types handed to the hook — `state.player.*`, `state.board.*`, `me.*` (see the `api/` section). There are **no read free functions** anymore.
-- **Write API** (`register_write_api`) — free functions that enqueue an `Action` onto the **issuing object's** `queue` (resolved from the per-call tag): `move(dir)` (enqueues `Move` then a `MOVE_COST` delay), `delay(secs)`/`now()` (queue pacing), `set_tile(n)`, `set_fg`/`set_bg`/`set_color`, `set_tag(target, tag, present)`, `log(s)`, `say(s)`/`say(s, dur)`, `scroll(lines)`, `send(target, fn [, arg])`, `teleport(x, y)`, `push(x, y, dir)`, `shift([[x, y], …])`, `alter_gems(n)`, `alter_health(dh)`, `set_key(color, present)`, `die()`. `scroll(lines)` takes a Rhai array whose elements are a string (text line) or a two-element `[choice_key, display_text]` (selectable choice). `shift` takes an array of two-int `[x, y]` arrays (a malformed entry logs an error) and rotates that ring of cells via `Board::apply_shift`.
+- **Write API** (`register_write_api`) — free functions that enqueue an `Action` onto the **issuing object's** `queue` (resolved from the per-call tag): `move(dir)` (enqueues `Move` then a `MOVE_COST` delay), `delay(secs)`/`now()` (queue pacing), `set_tile(n)`, `set_fg`/`set_bg`/`set_color`, `set_tag(target, tag, present)`, `log(s)`, `say(s)`/`say(s, dur)`, `scroll(lines)`, `send(target, fn [, arg])`, `teleport(id, x, y)` (jump entity `id` to a cell; `me.id` = self, `-1` = player), `push(x, y, dir)`, `shift([[x, y], …])`, `alter_gems(n)`, `alter_health(dh)`, `set_key(color, present)`, `die()`. `scroll(lines)` takes a Rhai array whose elements are a string (text line) or a two-element `[choice_key, display_text]` (selectable choice). `shift` takes an array of two-int `[x, y]` arrays (a malformed entry logs an error) and rotates that ring of cells via `Board::apply_shift`.
 - **Queue draining (two-tier):** each object's actions sit in its own `ObjQueue` until `ObjectInfo::drain(board_queue, dt)` promotes them onto the shared **board queue** (`Vec<BoardAction>`): it first eats leading `Delay` actions with `dt` (a delay longer than `dt` is decremented and stops the drain — this caps object speed), then moves the run of ready actions across. `GameState` takes the board queue with `take_board_queue()` and applies it after the batch, so scripts mutate without a `&mut GameState` borrow. Errors bypass the queues via the error sink (`take_errors()`).
 - **Constants in scope:** only `Registry` is pushed into each object's scope (the `me`/`state` views are hook *parameters* now). `register_global_constants` registers the `North`/`South`/`East`/`West` `Direction` values and the 16 named colors as a **global module**, visible at any call depth (including Rhai→Rhai calls and helper functions) — unlike scope constants such as `Registry`.
 - `Registry` (a `Board`-handle wrapper) — `Registry.get(key)` / `set(key, value)` / `get_or(key, default)` read and write the board's `registry: HashMap<String, RegistryValue>`, which **persists across board transitions**. `set(key, ())` removes a key; unsupported value types are ignored; `get_or` only returns the stored value when it matches the default's Rhai type.