grid.js

const cons = (head, tail) =>
    bool => bool ? head : tail

const head = pair => pair(true)
const tail = pair => pair(false)

const pairToString = pair => "(" + head(pair) + "," + tail(pair) + ")"

const myPair = cons(1, 2)
console.log(pairToString(myPair))
console.log(head(myPair))
console.log(tail(myPair))

const list = arr => {
    arr.push(null);
    return arr.reduceRight((acc, curr) => cons(curr, acc))
}

const listToString = list => {
    const elems = list =>
        list == null ?
            "" :
            " " + head(list) + elems(tail(list))
    return "(" + elems(list).substring(1) + ")"
}

const myList = list([1, 2, 3, 4, 5])
console.log(listToString(myList))

A true 4x4 masterpiece!