lisp.js

const inputString = '(console.log (add 3 5 8 123 (minus 32 2 2 2)))';

const commands = {
  'console.log': console.log,
  inc(a, b) {
    return Number.parseInt(a) + Number.parseInt(b);
  },
  dec(a, b) {
    return Number.parseInt(a) - Number.parseInt(b);
  },
  add(...args) {
    return args.reduce(this.inc);
  },
  minus(...args) {
    return args.reduce(this.dec);
  },
};

function findMatchingExpr(string, position = 0) {
  let counter = 0;

  while (position < string.length) {
    switch (string[position]) {
      case '(':
        counter++;
        break;

      case ')':
        counter--;
        break;

      default:
        break;
    }

    if (counter === 0) {
      return position + 1;
    }

    position++;
  }
}

function extractBrace(string, pos = 0) {
  const firstBrace = string.indexOf('(', pos);
  const lastBrace = findMatchingExpr(string, firstBrace);

  return string.slice(firstBrace, lastBrace);
}

function indexes(string, search) {
  return string
    .split('')
    .reduce((acc, element, index) => (element === search ? acc.concat(index) : acc), []);
}

function extractBraces(string) {
  const braces = [];

  for (const index of indexes(string, '(')) {
    braces.push(extractBrace(string, index));
  }

  return braces;
}

function runCommand(string) {
  const [command, ...args] = string.slice(1, -1).split(' ');
  return commands[command](...args);
}

function extractCommand(string) {
  const braces = extractBraces(string).reverse();

  for (const braceIndex in braces) {
    const command = braces[braceIndex];
    const result = runCommand(command);

    braces.forEach((otherBrace, index) => {
      braces[index] = otherBrace.replace(command, result);
    });
  }
}

extractCommand(inputString);