Movement planned in full, then committed: a Planner builds a plan (moving and destroyed ids) by running content's movement responses (OPEN/SHUT, PUSH, STOP) for every step, rolling back failed branches. Edge of level blocks; YOU objects move furthest-ahead first; rules are reparsed once after movement. Harness: move/move_dir(Dir), posOf, kindsAt. Expansion Drop: PULL as one word plus one content response. Co-Authored-By: Claude Opus 5.5 <[email protected]>
18 lines
2.3 KiB
Markdown
18 lines
2.3 KiB
Markdown
# Module 8 reference engine (Rust)
|
|
|
|
The course's own engine as of the end of Module 8. Part I's card engine is unchanged, and all of its tests still pass. The Part II engine in `src/engine/puzzle/` now moves objects: each `YOU` object's move is planned in full, push chain and all, and only then committed. Module 7's reference was the starting point, so a diff between the two shows what this module adds.
|
|
|
|
- `cards/` (at the crate root; not in this directory): Part I's card data, a copy of `course/cards/` staged by `tools/verify-references.mjs`. Part II doesn't read it.
|
|
- `src/engine/puzzle/`: the Part II engine. It names no noun: the engine's own words are the operators `IS`, `AND`, `NOT`, the meta-noun `TEXT`, the property `PUSH` of the base rule `TEXT IS PUSH`, and from Module 8 the property `YOU`, which picks the objects that move.
|
|
- `grid.rs`: the level format, object kinds and the board. Module 8 adds `Board::find`, `Board::remove`, `Board::shift`, `Board::at` and `Display` for `Kind` (the kind as placed, for `kinds_at`).
|
|
- `movement.rs` (new): validate, then commit. `Planner` (`try_move`, `staying_at`, `destroy`, `has`), `Step`, `Plan`, `Response` and `Dir`. The planner reads the board and plans one step at a time; for each step it runs content's movement responses in order, and rolls back everything a step added if a response blocks it. The edge of the level blocks every step.
|
|
- `level.rs`: a level in play. Module 8 adds `Level::move_you`: the `YOU` objects move one at a time, furthest ahead first, each planned and then committed; the rules are reparsed once at the end. `has_property` is `false` for a destroyed object.
|
|
- `word.rs`, `parse.rs`, `resolve.rs`: unchanged.
|
|
- `mod.rs`: the module's exports.
|
|
- The rest of `src/engine/`: Part I, unchanged.
|
|
- `src/content/movement.rs` (new) and `src/content/mod.rs`: the movement responses, in the order the engine runs them: `OPEN`/`SHUT`, `PUSH`, `STOP`. What a property does when something moves is content, not engine.
|
|
- `src/content/words.json`: Module 8 adds `OPEN` and `SHUT`.
|
|
- `src/harness.rs`: the adapter the course tests call. Module 8 adds `Baba::move_dir`, `Baba::pos_of`, `Baba::kinds_at`, and re-exports `Dir`.
|
|
|
|
Run it with the module's tests: `node tools/verify-references.mjs 08` from the course repository.
|