Why I am learning category theory(the.scapegoat.dev)

   let balances = List(1, 4, 23, 7)
   let overallBalance = ???

   let overallBalance = sum(balances)

   let overallBalance = combineAll(balances)
   let concattenated = combineAll(listOfStrings)

    class Balance( private innerValue of type number/money )

   let balances = List(Balance(1), Balance(4), Balance(23), Balance(7))
   let overallBalance = sum(balances)

    a monoid exists for class Balance using Balance.innerValue

   let balances = List(Balance(1), Balance(4), Balance(23), Balance(7))
   let overallBalance = combineAll(balances)

    let listOfBalances = List(
      List(Balance(1), Balance(4)),
      List(Balance(23), Balance(7)),
      List(),
      List(Balance(42)
    )

    sum(listOfBalances.map(balances => sum(balances)))

    let overallBalance = combineAll(combineAll(listOfBalances))

    let map1 = Map("user1" -> Balance(3), "user2" -> Balance(4))
    let map2 = Map("user2" -> Balance(5), "user3" -> Balance(6))
    let aggregated = combine(map1, map2)

    Map("user1" -> Balance(3), "user2" -> Balance(9), "user3" -> Balance(6))

   const transfer = (x, from, to, onSuccess, onError) => {
      return getAccountMoney(from, (f) => {
         if (f < x) { 
             return onError();
         } else { 
             return getAccountMoney(to, (t) => {
                 return setAccountMoney(to, t+x, () => {
                     return setAccountMoney(from, f-x, onSuccess, onError);
                 }, onError);
             }, onError);
         }, onError);
     }
   }

    type Dialogue = [Response] -> [Request]
    main :: Dialogue