Files
systemic-game-design-course/course/10-spellgrid/reference/rust
Lucas WintherandClaude Fable 5.2 429137a6ef fix(reference): Death Events remember a right-hand neighbour, not a board index
A Deathrattle summon used the dying minion's board index from before the
Death Creation Step removed anything. That index is stale when a minion to
its left dies in the same step, so the token landed one place too far right.

Each Death Event now records `before`: the nearest minion to the right that
is not dying in the same step. The position handed to the effect context is
resolved when the trigger resolves: the current index of `before`, or the
right end. Applied to the Rust and TS references of Modules 3-10.

Module 3 gains two tests, documented in scenarios.md:
test_03_summon_position_after_simultaneous_deaths (fails before the fix) and
test_03_simultaneous_summons_keep_board_order.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>
2026-11-11 09:15:48 +01:00
..
2026-10-29 05:01:27 +01:00
2026-10-29 05:01:27 +01:00
2026-10-29 05:01:27 +01:00
2026-10-29 05:01:27 +01:00

Module 10 reference engine (Rust)

The course's own engine as of the end of Module 10: Part I's card engine and Part II's grid engine, joined by SpellGrid. Every test from Modules 1–9 still passes. Module 9's reference was the starting point, so a diff between the two shows what this module adds.

  • cards/ and levels/ (at the crate root; not in this directory): copies of course/cards/ plus course/10-spellgrid/cards/ (SpellGrid's own cards, which only Module 10 on receives), and of course/10-spellgrid/levels/, staged by tools/verify-references.mjs (and by tools/play-spellgrid.mjs, to play the command line).
  • src/engine/spellgrid.rs (new): the only module that uses both engines. SpellGrid keeps a World and a puzzle::Level in step through the three seams: rule_auras (rules in force → auras), CardSide::destroy (hazard victims → one Destroy Sequence → the Death Creation Step), and CardSide::sequence (after each Sequence: write TextSpawned text, take dead minions off the grid, reparse). It also keeps one id space: a minion's id is its grid object's id.
  • Part I (src/engine/, outside puzzle/):
    • queue.rs: END_OF_PHASE ([DeathCreation, AuraUpdate]) is the list of steps at the end of the outermost Phase, read from the world. Action::SpawnText records a TextSpawned event.
    • world.rs: set_rule_auras/rule_auras (auras that no minion carries), set_end_of_phase/end_of_phase, entity_count.
    • aura.rs: an Aura Update adds the rule auras for both players; activations applies an Aura::TriggerCap.
    • card.rs: Aura::TriggerCap (not in the card format: only SpellGrid makes it), and CardDef::noun.
    • effect.rs: spawnText is an action, not a panic. event.rs: TextSpawned.
  • Part II (src/engine/puzzle/):
    • level.rs: Destroy and remove_all. step_with and move_you_with take a destroy function, which movement, conversion (X IS NOT X) and hazards hand their victims to; step and move_you pass remove_all. reparse and board_mut are public.
    • grid.rs: Board::reserve_id, and cards/hand in LevelDef (read only by SpellGrid), with LevelCard.
  • src/content/seams.json and seams() (new): which nouns name a trigger (DEATHRATTLE) and which properties multiply one (DOUBLE, twice, stacking: "max"). words.json adds the SpellGrid nouns, DEATHRATTLE and DOUBLE.
  • src/harness.rs: Module 10 adds new_spell_grid and SpellGrid, including the test hook with_naive_aura_timing(), which reverses END_OF_PHASE for one game.
  • src/cli.rs and src/bin/spellgrid.rs (new): the command line, cargo run --bin spellgrid -- levels/l1-double-tap.json run from a staged directory (it needs cards/ and levels/): node tools/play-spellgrid.mjs rust l1 from the course repository stages one in a temporary directory and starts it. w a s d move, c <card> [x y] casts a spell (at the minion on that tile) or plays a minion (onto that empty tile), q quits. tests/cli.rs plays it from a script; it is the reference's own check, not a course test.

Run it with the module's tests: node tools/verify-references.mjs 10 from the course repository.