integer

foo.js

const displayWidth = 8;

const maxInt = parseInt("9".repeat(displayWidth));
const minInt = parseInt("-" + "9".repeat(displayWidth - 1));

const wrongValue = new RuntimeError('некорректное значение');
const wrongOperation = new RuntimeErr('некорректная операция (переполнение)')

const createInteger = (string) => {
  const value = parseInt(string);
  let error = null;
  if (Number.isInteger(value)) {
  } else {
    error = wrongValue;
  }

  return {
    val: value,
  }
}

const createRegister = ({
  writeable = true,
  readable = true,
} = {}) => {
  return {
    get writeable() {
      return writeable;
    },
    get readable() {
      return readable;
    }
  }
}

const createWORegister = () => createRegister({ writeable: true, readable: false });
const createRORegister = () => createRegister({ readable: true, writeable: false });

createRegister.RO = createRORegister;
createRegister.WO = createWORegister;

const reg = createRegister.RO();

console.log(reg.writeable);
console.log(reg.readable);