Initial commit.

.gitattributes

+# Disable line-ending conversions for this repository.
+* -text

.gitignore

+# dependencies
+/node_modules
+
+# testing
+/coverage
+
+# production
+/build
+
+# environments
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# misc
+*~
+.DS_Store

.gitmodules

+[submodule "eslint-config"]
+	path = eslint-config
+	url = git@git.unl.edu:csce-310/eslint-config.git

README.md

+# Homework 4
+
+Starter code for Homework 4 in the CSCE 310 course at UNL.
+
+# Quick Start
+
+Recursively clone this repository and `cd` into the root folder:
+
+```
+$ git clone --recursive git@git.unl.edu:csce-310/2023-fall-homework-4.git
+$ cd 2023-fall-homework-4
+```
+
+(If you forget `--recursive` when cloning, you can `cd` into your clone and run
+`git submodule update --init --recursive` instead.)
+
+Install dependencies:
+
+```
+$ npm install
+```
+
+# Instructions
+
+See <https://canvas.unl.edu/courses/158348/assignments/1576251>.

eslint-config @ 16524f5a

+Subproject commit 16524f5ac58d4b13378261f1ab29bc1acc2a2099

homework-4.code-workspace

+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {
+		"files.eol": "\n",
+		"files.exclude": {
+			"**/node_modules": true
+		},
+		"files.trimFinalNewlines": true,
+		"files.trimTrailingWhitespace": true
+	}
+}

homework-4/.gitignore

+# dependencies
+/node_modules
+
+# testing
+/coverage
+
+# production
+/build
+
+# environments
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# misc
+*~
+.DS_Store

homework-4/package.json

+{
+  "name": "@unlcsce/homework-4",
+  "version": "1.0.0",
+  "description": "Starter code for Homework 4.",
+  "type": "module",
+  "private": true,
+  "license": "UNLICENSED",
+  "scripts": {
+    "lint:js": "eslint --max-warnings 0 ./src",
+    "lint": "run-s --continue-on-error lint:**",
+    "test-once:sum": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the addition monoid\"",
+    "test-once:file": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the file-method monoid\"",
+    "test-once:simpleXML": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the simple-XML monoid\"",
+    "test-once:robot": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the robot-joint monoid\"",
+    "test-once:signal": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the periodic-signal monoid\"",
+    "test-once:minimaGap": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"the narrowest-gap-between-minima monoid\"",
+    "test-once": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js --watchAll"
+  },
+  "dependencies": {
+    "npm-run-all": "^4.1.5"
+  },
+  "devDependencies": {
+    "@unlcsce/eslint-config": "file:../eslint-config",
+    "eslint": "^8.20.0",
+    "jest": "^29.5.0",
+    "jest-environment-node": "^29.5.0"
+  },
+  "eslintConfig": {
+    "extends": "@unlcsce"
+  },
+  "jest": {
+    "clearMocks": true,
+    "resetMocks": false,
+    "restoreMocks": false,
+    "setupFilesAfterEnv": [
+      "./src/setupTests.js"
+    ],
+    "testEnvironment": "./src/testing/failFast.js",
+    "transform": {}
+  },
+  "//": [
+    "See https://github.com/facebook/jest/issues/9430 for information on Jest+ES6."
+  ]
+}

homework-4/src/file.js

+/* IMPORTANT: Remove this directive when you start working on the code so that
+ * the linter will warn you about code style issues. */
+/* eslint-disable no-useless-constructor */
+
+class MonoidElement {
+  constructor() {
+    // Implement this constructor per the assignment instructions.
+  }
+
+  get valid() {
+    return false; // Implement this getter per the assignment instructions.
+  }
+}
+
+export const IDENTITY_ELEMENT = new MonoidElement(); // Define this object per the assignment instructions.
+
+export function encodeAsMonoidElement(method) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}
+
+export function combineMonoidElements(left, right) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}

homework-4/src/mapReduce.js

+import { Worker } from 'worker_threads';
+
+class ModuleWorker extends Worker {
+  constructor(path) {
+    const code = `import '${new URL(path, import.meta.url).href}';`;
+    super(new URL(`data:text/javascript,${encodeURIComponent(code)}`));
+  }
+
+  dispatch(data) {
+    this.postMessage(data);
+    return new Promise((resolve) => this.once('message', resolve));
+  }
+}
+
+function iterativeReduce(identityElement, combineMonoidElements, sequence) {
+  let result = identityElement;
+  for (const element of sequence) {
+    result = combineMonoidElements(result, element);
+  }
+  return result;
+}
+
+export async function parallelMapReduce(proceduresURL, sequence, workerCount) {
+  console.assert(workerCount > 0, `Cannot distribute work to a nonpositive (${workerCount}) number of threads.`);
+  const {
+    IDENTITY_ELEMENT,
+    combineMonoidElements,
+  } = await import(proceduresURL);
+  const workers = [...Array(workerCount)].map(() => new ModuleWorker('./worker.js'));
+  const jobs = workers.map((worker, workerIndex) => {
+    const low = Math.floor(workerIndex * sequence.length / workerCount);
+    const high = Math.floor((workerIndex + 1) * sequence.length / workerCount);
+    return worker.dispatch({
+      proceduresURL,
+      data: [...sequence.slice(low, high)],
+    });
+  });
+  const threadResults = (await Promise.all(jobs)).map(
+    (element) => Object.assign(Object.create(Object.getPrototypeOf(IDENTITY_ELEMENT)), element),
+  );
+  for (const worker of workers) {
+    worker.terminate();
+  }
+  return iterativeReduce(IDENTITY_ELEMENT, combineMonoidElements, threadResults);
+}

homework-4/src/minimaGap.js

+class MonoidElement {
+  constructor() {
+    this.gap = Infinity; // Implement this constructor per the assignment instructions.
+  }
+}
+
+export const IDENTITY_ELEMENT = new MonoidElement(); // Define this object per the assignment instructions.
+
+export function encodeAsMonoidElement(number) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}
+
+export function combineMonoidElements(left, right) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}

homework-4/src/robot.js

+/* IMPORTANT: Remove these directives when you start working on the code so that
+ * the linter will warn you about code style issues. */
+/* eslint-disable no-unused-vars */
+/* eslint-disable no-useless-constructor */
+
+const FULL_ROTATION = 360; // degrees
+
+class MonoidElement {
+  constructor() {
+    // Implement this constructor per the assignment instructions.
+  }
+
+  isSafe(startingAngle, safetyMargin) {
+    return true; // Implement this method per the assignment instructions.
+  }
+}
+
+export const IDENTITY_ELEMENT = new MonoidElement(); // Define this object per the assignment instructions.
+
+export function encodeAsMonoidElement(changeInAngle) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}
+
+export function combineMonoidElements(left, right) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}

homework-4/src/setupTests.js

+// Extra imports for working around a V8 bug; see below.
+import { SourceTextModule } from 'vm';
+import { fileURLToPath } from 'url';
+import { resolve, dirname } from 'path';
+import { readFileSync } from 'fs';
+
+import { jest } from '@jest/globals';
+
+// This is included for consistency with `create-react-app`.  It may be become
+// unnecessary in future versions of Jest (see
+// https://github.com/facebook/jest/issues/9430#issuecomment-616232029), but
+// Jest may also choose to move away from magic globals and use imports instead,
+// which are already opt-in (see https://github.com/facebook/jest/issues/4473).
+globalThis.jest = jest;
+
+// Work around <https://bugs.chromium.org/p/chromium/issues/detail?id=1244145>,
+// a rather nasty bug in V8 where source code dynamically imported with
+// host-defined options (see, e.g., the `options` parameter to
+// <https://nodejs.org/api/vm.html#class-vmsourcetextmodule>) will be cached
+// with only its source text as key so that later imports with different options
+// are incorrectly treated as cache hits.
+//
+// Since Jest uses different options (see, e.g., `loadEsmModule` in
+// `…/node_modules/jest-runtime/build/index.js`) for each test file, that means
+// that while processing any test file after the first, `mapReduce.js` is still
+// associated with an old test environment, and any attempts by it to
+// dynamically import a monoid go through an environment that has been torn
+// down.  They therefore fail.
+//
+// Since `mapReduce.js` is unmocked and code under test, we don't need any of
+// Jest's special import handling (e.g., support for mocking) in it or any of
+// its imports, so here we preload `mapReduce.js` into V8's cache without any
+// host-defined options.  There are still false cache hits, but at least none of
+// the cache entries are associated with a test environment.
+//
+// eslint-disable-next-line no-new
+new SourceTextModule(readFileSync(resolve(dirname(fileURLToPath(import.meta.url)), 'mapReduce.js'), 'utf8'));

homework-4/src/signal.js

+export const UNKNOWN = 'UNKNOWN';
+export const INCONSISTENT = 'INCONSISTENT';
+
+class MonoidElement {
+  constructor() {
+    this.period = UNKNOWN; // Implement this constructor per the assignment instructions.
+  }
+}
+
+export const IDENTITY_ELEMENT = new MonoidElement(); // Define this object per the assignment instructions.
+
+export function encodeAsMonoidElement(signal) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}
+
+export function combineMonoidElements(left, right) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}

homework-4/src/simpleXML.js

+/* IMPORTANT: Remove this directive when you start working on the code so that
+ * the linter will warn you about code style issues. */
+/* eslint-disable no-useless-constructor */
+
+class MonoidElement {
+  constructor() {
+    // Implement this constructor per the assignment instructions.
+  }
+
+  get valid() {
+    return true; // Implement this getter per the assignment instructions.
+  }
+}
+
+export const IDENTITY_ELEMENT = new MonoidElement(); // Define this object per the assignment instructions.
+
+export function encodeAsMonoidElement(character) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}
+
+export function combineMonoidElements(left, right) {
+  return IDENTITY_ELEMENT; // Implement this function per the assignment instructions.
+}