curried-add.js

// finished version of https://youtu.be/yIcve5wIuAg

function add(...args) {
  function curriedAdd(...args2) {
    return add(...args, ...args2)
  }
  curriedAdd.value = args.reduce((total, current) => total + current)
  return curriedAdd
}


console.assert(add(2, 5, 1).value === 8, 'does not work first case')
console.assert(add(2)(5)(1).value === 8, 'does not work for second case')

console.log(add(2)(5)(1).value)

Nice one. I think we can call add function like add(curriedAdd.value, ...args2) from the curriedAdd function. That will reduce the number of operations in reduce function.

const add = (...args) => {
    const curriedAdd = (...args1) => {
        return add(curriedAdd.value, ...args1)
    }
    curriedAdd.value = args.reduce((total, current) => total + current)
    return curriedAdd
}

console.log(add(2,3,5,12,-1))
console.log(add(2,3)(5)(8,6)(9))

Why not adding:

Object.defineProperty(curriedAdd, 'value', {
  get: () => args.reduce((total, current) => total + current)
});

This would avoid computing reduce many time for nothing.