hotkeys.js

function makeHotKeys() {
  let commands = {};
  const keyMap = {};
  let largestKeyValue = 0;

  let bitValues = [];
  function bitValue(bit) {
    bitValues[bit] = bitValues[bit] || 2n ** BigInt(bit);
    return bitValues[bit];
  }

  function keyValue(key) {
    if (!keyMap.hasOwnProperty(key)) {
      keyMap[key] = largestKeyValue++;
    }
    return bitValue(keyMap[key]);
  }

  function getKeysHash(keys) {
    return keys.reduce((val, key) => val + keyValue(key), 0n);
  }

  function getCommand(keys) {
    const hash = getKeysHash(keys);
    return commands[hash];
  }

  function setCommand(keys, commandName) {
    const hash = getKeysHash(keys);
    commands[hash] = commandName;
  }

  return { setCommand, getCommand };
}

const { setCommand, getCommand } = makeHotKeys();

function preprocess(commandList) {
  commandList.forEach((str) => {
    const parts = str.split(' ');
    commandName = parts.pop();
    setCommand(parts, commandName);
  });
}

function findCommand(pressedKeysStr) {
  const pressedKeys = pressedKeysStr.split(' ');
  return getCommand(pressedKeys) || '';
}