devsnek

// console.log(solveRPN('5 3 6 * + 5 3 / - 7 +')); // becomes `28.333333333333332`

function solveRPN(input) {
  const stack = [];
  const items = input.trim().split(' ');
  for (const item of items) {
    if (!isNaN(item) && isFinite(item)) {
      stack.push(parseFloat(item));
    } else {
      const [a, b] = [stack.pop(), stack.pop()];

devsnek

This is a parser/lexer for mathematical expressions.

It all starts with the parse/1 function, which begins by building an array (in a rather ineffecient way) from the iterator returned by lex/2. The lexer is the part of this I had the most fun with.

It basically brute-forces the beginning of the string with regex until something matches up, at which point it removes that match from the string and yields the token.

devsnek

const Module = require('module');
require.fromString = (str, filename = '') => {
  const m = new Module(filename, module.parent);
  if (typeof __dirname !== 'undefined') m.paths = Module._nodeModulePaths(__dirname);
  m._compile(str, filename);
  return m.exports;
}

devsnek

const sharedBuffer = new SharedArrayBuffer(2 * Int32Array.BYTES_PER_ELEMENT);
const sharedArray = new Int32Array(sharedBuffer);

// new semaphore with max of 10
const s = Semaphore.create(sharedArray, 0, 10);

s.acquire(11) // false
s.acquire(10) // true
s.acquire() // false
s.release(5) // true

devsnek

const l = require('fast-levenshtein');
const has = (o, p) => Object.prototype.hasOwnProperty.call(o, p);

function leven(target, list) {
  const sorted = [];
  for (const item of list) {
    const score = l.get(target, item);
    sorted.splice(+score - 1, 0, item);
  }
  let ret;

devsnek

function unindent(str, ...keys) {
  if (Array.isArray(str)) {
    const copy = [];
    for (const i in keys) {
      copy.push(str[i]);
      copy.push(keys[i]);
    }
    str = copy.join('');
  }
  const lines = str.split('\n').filter((l) => l);

devsnek

const Module = require('module');
const fs = require('fs');
const path = require('path');
const util = require('util');
const writeFileAsync = util.promisify(fs.writeFile.bind(fs));

const CACHE_NAME = 'package-cache.json';

const defaultResolveFilename = Module._resolveFilename.bind(Module);
const cwd = process.cwd();

devsnek

#include <iostream>
#include <sys/stat.h>
#include <string>

using namespace std;

class Node {
private:
	int value;
	Node* next;

devsnek

const kMap = Symbol('map');
class EventEmitter {
  constructor() {
    this[kMap] = new Map();
  }
  on(event, handler, once = false) {
    const fn = ({ detail }) => handler.apply(this, detail);
    this[kMap].set(handler, { fn, once });
    return window.addEventListener(event, fn, { once });
  }

devsnek

diff --git a/lib/internal/vm/Module.js b/lib/internal/vm/Module.js
index a8625ef76b..462b4b5c11 100644
--- a/lib/internal/vm/Module.js
+++ b/lib/internal/vm/Module.js
@@ -33,6 +33,7 @@ const perContextModuleId = new WeakMap();
 const wrapMap = new WeakMap();
 const dependencyCacheMap = new WeakMap();
 const linkingStatusMap = new WeakMap();
+const linkingCache = new WeakMap();