Files
functional-programming-snake/js/solutions/life/app.js
T
Lucas WintherandClaude Fable 5.2 edd57f0148 feat(course): audit fixes and twelve extensions (Modules 7b, 12, 13)
Audit pass:
- Frame rule counts frames since the last move, so every step lasts
  exactly movesEvery(score) frames, also right after a speed-up
- clampTime + MAX_GAP_MS: a hidden tab no longer replays the whole gap
- Pong Restart keeps held keys
- Fact corrections (mulberry32 output coverage, Haskell IO, uniform)
- New fixture cases from a mutation analysis

Extensions (all three tracks, shared fixtures, course text):
- Turn queue (Exercise 10.6), persisted high score (10.7),
  replay viewer (10.8), play() end-to-end helper (9.5)
- Optional State (4.7) and optional Module 7b, stack-safe IO
- Module 12, property-based testing with generators, shrinking,
  invariants and a model-based oracle
- Module 13, Conway's Life with a Click event
- JS type checking via jsconfig, JSDoc and types.d.ts
- Maintainer tools: scripts/mutate.mjs, scripts/typecheck-js.sh,
  Playwright end-to-end suite (e2e/, scripts/e2e.sh)

Docs: docs/contract.md is the canonical contract; specs and build log
under docs/superpowers.

Verified: JS 728, Scala 689, F# 691 unit tests; stubs and progression
M01-M13 and M07b; 176 end-to-end tests on Chromium and WebKit.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>
2026-11-11 12:05:29 +01:00

45 lines
1.9 KiB
JavaScript

// m13 life app: the same wiring as Snake and Pong, with a third kind of input, the mouse.
import { LW, LH, LCELL, initialLife, LifeAction } from './model.js'
import { lifeUpdate } from './rules.js'
import { lifeView } from './view.js'
import { map as mapIO, randomSeed, drawScene } from '../io.js'
import { keyDowns, clicks, interval, map, filterMap, merge, scan, startWith, clampTime } from '../stream.js'
import { MAX_GAP_MS } from '../app.js'
/** @import { LifeState, Stream, Program } from '../types' */
/** Milliseconds between two generations while the world runs. */
export const GEN_MS = 150
const keys = {
' ': LifeAction.TogglePause,
n: LifeAction.Step, N: LifeAction.Step,
c: LifeAction.Clear, C: LifeAction.Clear,
r: LifeAction.Randomize, R: LifeAction.Randomize,
}
/** A key to an action, or null.
* @type {(key: string) => LifeAction | null} */
export const lifeKey = (key) => (Object.hasOwn(keys, key) ? keys[key] : null)
/** A click at canvas pixel (x, y) to `Toggle` of the cell under it, or null when it is not on the board.
* @type {(x: number, y: number) => LifeAction | null} */
export const lifeClick = (x, y) => {
const cell = { x: Math.floor(x / LCELL), y: Math.floor(y / LCELL) }
return x >= 0 && y >= 0 && cell.x < LW && cell.y < LH ? LifeAction.Toggle(cell) : null
}
/** @type {Stream<LifeAction>} */
export const lifeActions = merge(
merge(
map(interval(GEN_MS), () => LifeAction.Frame),
filterMap(keyDowns, lifeKey)),
filterMap(clicks, (p) => lifeClick(p.x, p.y)))
/** @type {(seed: number, actions: Stream<LifeAction>) => Stream<LifeState>} */
export const lifeStates = (seed, actions) =>
startWith(scan(actions, lifeUpdate, initialLife(seed)), initialLife(seed))
/** @type {Program} */
export const lifeMain = mapIO(randomSeed, (seed) =>
clampTime(map(lifeStates(seed, lifeActions), (state) => drawScene(lifeView(state))), MAX_GAP_MS))