Merge pull request #1 from sondregj/development

💡 Rule functions

README.md

@@ -1,23 +1,22 @@
 <h1 align="center">
-  <span style="font-size: 100px;">🧫</span>
+  <span style="font-size: 128px;">🧫</span>
+
   <br>
   <br>
-  Conway
+
+Conway
+
 </h1>
 
-<h4 align="center">Conway's Game of Life</h4>
+<h4 align="center">Cellular Automata</h4>
 
 <p align="center">
-  <a href="https://travis-ci.org/sondregj/conway">
-    <img alt="Travis Build Status" src="https://img.shields.io/travis/sondregj/conway.svg?style=flat-square">
-  </a>
-
   <a href="https://npmjs.com/conway">
-  	<img alt="npm (latest)" src="https://img.shields.io/npm/v/conway/latest.svg?style=flat-square">
+  	<img alt="npm (latest)" src="https://img.shields.io/npm/v/@sondregj/conway/latest.svg?style=flat-square">
   </a>
 
   <a href="https://npmjs.com/conway">
-    <img alt="npm bundle size" src="https://img.shields.io/bundlephobia/min/conway.svg?style=flat-square">
+    <img alt="npm bundle size" src="https://img.shields.io/bundlephobia/min/@sondregj/conway.svg?style=flat-square">
   </a>
 
   <a href="https://github.com/sondregj/conway">
@@ -33,16 +32,73 @@
   </a>
 </p>
 
-A simple Game of Life implementation, in TypeScript.
+A simple cellular automaton implementation, in TypeScript.
 
 ## Usage
 
+Install by running `npm install @sondregj/conway`
+
+```javascript
+import { advance } from '@sondregj/conway'
+
+const world = {
+    cells: [
+        [{ alive: false }, { alive: false }, { alive: true }],
+        [{ alive: true }, { alive: false }, { alive: true }],
+        [{ alive: false }, { alive: true }, { alive: true }],
+    ],
+}
+
+const day1 = advance(world)
+```
+
+You can also define custom rule functions.
+
+```javascript
+import { advance } from '@sondregj/conway'
+
+const world = {
+    cells: [
+        [{ alive: false }, { alive: false }, { alive: true }],
+        [{ alive: true }, { alive: false }, { alive: true }],
+        [{ alive: false }, { alive: true }, { alive: true }],
+    ],
+}
+
+const rules = (board, cell, x, y) => !cell.alive
+
+const day1 = advance(world, rules)
+```
+
+A convenience function for initializing boards is also included.
+
 ```javascript
 import { initializeBoard, advance } from '@sondregj/conway'
 
-const board = initializeBoard(30, 30, { random: true })
+const genesis: Board = initializeBoard(64, 64, { random: true })
+
+const day1 = advance(genesis)
+```
+
+The following TypeScript types are included.
+
+```typescript
+import { Board, BoardTick, Cell, RuleFunction } from '@sondregj/conway'
+
+const world: Board = {
+    cells: [
+        [{ alive: false }, { alive: false }, { alive: true }],
+        [{ alive: true }, { alive: false }, { alive: true }],
+        [{ alive: false }, { alive: true }, { alive: true }],
+    ],
+}
+
+const cell: Cell = { alive: true }
+
+const advance: BoardTick = (board: Board): Board => board
 
-const nextStep = advance(board)
+const rules: RuleFunction = (board: Board, cell: Cell, x: number, y: number): boolean =>
+    true
 ```
 
 ## License

jest.config.js

@@ -11,5 +11,5 @@ module.exports = {
 		"ts",
 		"js"
 	],
-	testRegex: "(/test/unit/.*|(\\.|/)(test|spec))\\.[jt]sx?$",
+	testRegex: "(/test/.*|(\\.|/)(test|spec))\\.[jt]sx?$",
 }

package.json

@@ -1,7 +1,7 @@
 {
 	"name": "@sondregj/conway",
-	"version": "0.1.0",
-	"description": "Conway's Game of Life in TypeScript",
+	"version": "1.0.0",
+	"description": "Cellular Automata in TypeScript",
 	"author": "Sondre Gjellestad <[email protected]> (https://sondregjellestad.space)",
 	"homepage": "https://github.com/sondregj/conway#readme",
 	"repository": {
@@ -38,6 +38,7 @@
 		"dist/**/*"
 	],
 	"keywords": [
-		"game-of-life", "conway"
+		"game-of-life",
+		"conway"
 	]
 }

src/advance.ts

@@ -0,0 +1,11 @@
+import { BoardTick, RuleFunction } from './types'
+
+import { conwayRules } from './rules'
+
+export const advance: BoardTick = (board, rules: RuleFunction = conwayRules) => ({
+    cells: board.cells.map((row, yIndex) =>
+        row
+            .map((cell, xIndex) => rules(board, cell, xIndex, yIndex))
+            .map(alive => ({ alive })),
+    ),
+})

src/index.ts

@@ -1,79 +1,7 @@
-import { Board, BoardTick, Cell } from './types'
+export { advance } from './advance'
 
-interface BoardInitializerConfig {
-    random?: boolean
-}
+export { initializeBoard } from './initializer'
+export { conwayRules } from './rules'
+export { neighborCount } from './utils'
 
-export const initializeBoard = (
-    width: number,
-    height: number,
-    config: BoardInitializerConfig = {},
-): Board => {
-    const { random } = config
-
-    const cells: Cell[][] = []
-
-    for (let y = 0; y < height; y++) {
-        cells[y] = []
-
-        for (let x = 0; x < width; x++) {
-            cells[y][x] = {
-                alive: random ? Math.random() > 0.5 : false,
-            }
-        }
-    }
-
-    return { width, height, cells }
-}
-
-export const neighborCount = (board: Board, x: number, y: number): number => {
-    const targets = [
-        [x - 1, y - 1],
-        [x - 1, y],
-        [x - 1, y + 1],
-        [x, y - 1],
-        [x, y + 1],
-        [x + 1, y - 1],
-        [x + 1, y],
-        [x + 1, y + 1],
-    ]
-        .filter(
-            ([xIndex, yIndex]) =>
-                Math.min(xIndex, yIndex) >= 0 &&
-                xIndex < board.width &&
-                yIndex < board.height,
-        )
-        .map(([xIndex, yIndex]) => ({ x: xIndex, y: yIndex }))
-
-    return targets
-        .map(target => board.cells[target.y][target.x])
-        .reduce((sum, cell) => (cell.alive ? sum + 1 : sum), 0)
-}
-
-export const advance: BoardTick = board => {
-    const { width, height } = board
-
-    const cells = board.cells.map((row, yIndex) =>
-        row.map((cell, xIndex) => {
-            const neighbors: number = neighborCount(board, xIndex, yIndex)
-
-            if (!cell.alive && neighbors === 3) {
-                return { alive: true }
-            }
-
-            if (neighbors < 2) {
-                return { alive: false }
-            }
-
-            if (neighbors > 3) {
-                return { alive: false }
-            }
-
-            return { ...cell }
-        }),
-    )
-
-    return { width, height, cells }
-}
-
-export { Board, BoardTick, Cell } from './types'
+export { Board, BoardTick, Cell, RuleFunction } from './types'

src/initializer.ts

@@ -0,0 +1,27 @@
+import { Board, Cell } from './types'
+
+interface BoardInitializerConfig {
+    random?: boolean
+}
+
+export const initializeBoard = (
+    width: number,
+    height: number,
+    config: BoardInitializerConfig = {},
+): Board => {
+    const { random } = config
+
+    const cells: Cell[][] = []
+
+    for (let y = 0; y < height; y++) {
+        cells[y] = []
+
+        for (let x = 0; x < width; x++) {
+            cells[y][x] = {
+                alive: random ? Math.random() > 0.5 : false,
+            }
+        }
+    }
+
+    return { cells }
+}

src/rules.ts

@@ -0,0 +1,20 @@
+import { RuleFunction } from './types'
+import { neighborCount } from './utils'
+
+export const conwayRules: RuleFunction = (board, cell, x, y) => {
+    const neighbors = neighborCount(board, x, y)
+
+    if (!cell.alive && neighbors === 3) {
+        return true
+    }
+
+    if (neighbors < 2) {
+        return false
+    }
+
+    if (neighbors > 3) {
+        return false
+    }
+
+    return cell.alive
+}

src/types.ts

@@ -1,14 +1,11 @@
-// Data types
 export interface Cell {
     alive: boolean
 }
 
 export interface Board {
-    width: number
-    height: number
-
     cells: Cell[][]
 }
 
-// Transform functions
-export type BoardTick = (board: Board) => Board
+export type BoardTick = (board: Board, ...args: any[]) => Board
+
+export type RuleFunction = (board: Board, cell: Cell, x: number, y: number) => boolean

src/utils.ts

@@ -0,0 +1,23 @@
+import { Board } from './types'
+
+export const neighborCount = (board: Board, x: number, y: number): number => {
+    return [
+        [x - 1, y - 1],
+        [x - 1, y],
+        [x - 1, y + 1],
+        [x, y - 1],
+        [x, y + 1],
+        [x + 1, y - 1],
+        [x + 1, y],
+        [x + 1, y + 1],
+    ]
+        .filter(
+            ([xIndex, yIndex]) =>
+                Math.min(xIndex, yIndex) >= 0 &&
+                xIndex < board.cells[0].length &&
+                yIndex < board.cells.length,
+        )
+        .map(([xIndex, yIndex]) => ({ x: xIndex, y: yIndex }))
+        .map(target => board.cells[target.y][target.x])
+        .reduce((sum, cell) => (cell.alive ? sum + 1 : sum), 0)
+}

test/advance.test.ts

@@ -0,0 +1,23 @@
+import { advance, Board } from '../src'
+
+test('Advance function works as expected', () => {
+    const world: Board = {
+        cells: [
+            [{ alive: false }, { alive: false }, { alive: true }],
+            [{ alive: true }, { alive: false }, { alive: true }],
+            [{ alive: false }, { alive: true }, { alive: true }],
+        ],
+    }
+
+    const day1 = advance(world)
+
+    const expected: Board = {
+        cells: [
+            [{ alive: false }, { alive: true }, { alive: false }],
+            [{ alive: false }, { alive: false }, { alive: true }],
+            [{ alive: false }, { alive: true }, { alive: true }],
+        ],
+    }
+
+    expect(day1).toStrictEqual(expected)
+})

test/utils.test.ts

@@ -0,0 +1,15 @@
+import { Board, neighborCount } from '../src'
+
+test('Neighbor count function works as expected', () => {
+    const world: Board = {
+        cells: [
+            [{ alive: false }, { alive: false }, { alive: true }],
+            [{ alive: true }, { alive: false }, { alive: true }],
+            [{ alive: false }, { alive: true }, { alive: true }],
+        ],
+    }
+
+    const count = neighborCount(world, 1, 1)
+
+    expect(count).toStrictEqual(5)
+})

tsconfig.json

@@ -1,6 +1,6 @@
 {
     "compilerOptions": {
-        "lib": ["es2019", "dom"],
+        "lib": ["es2019"],
         "module": "commonjs",
         "target": "es6",
         "declaration": true,