indongyoo

// 세 번째 인자에 `filter(selected)`를 전달하여 선택된 상품의 수량만 합산
console.log( pdts.total(quantity, products, filter(selected)) ); // 7

pdts.selected = {
  // pdts.total의 before에 ...filter(selected) 추가
  quantity: _ => pdts.total(quantity, _, filter(selected)),
  price: _ => pdts.total(pdt.totalPrice, _, filter(selected)),
  // pipe로도 확장 가능
  discountedPrice: pipe(filter(selected), pdts.discountedPrice)
};

indongyoo

const products = [
  { id: 1, selected: true, name: 'A 반팔티', price: 12000, discount: 2000, quantity: 3 },
  { id: 2, selected: false, name: 'B 후드티', price: 30000, discount: 0, quantity: 3 },
  { id: 3, selected: true, name: 'C 폰케이스', price: 20000, discount: 0, quantity: 2 },
  { id: 4, selected: false, name: 'D 반팔티', price: 12000, discount: 2000, quantity: 4 },
  { id: 5, selected: true, name: 'E 쿠션', price: 25000, discount: 5000, quantity: 2 }
];

// 네임 스페이스 - 상품들에 대한 함수들
const pdts = {};

indongyoo

const add = (a, b) => a + b;
const sub = (a, b) => a - b;
const mult = (a, b) => a * b;

const baseCalcF = calc => (...fs) => a => go(
  map(f => f(a), fs),
  reduce(calc));
  
                // 5 + 10, 5 + 20
baseCalcF(add)(a => a + 10, a => a + 20)(5);

indongyoo

const p1 = {
  id: 1,
  selected: true,
  name: 'A 반팔티',
  price: 12000,
  discount: 2000,
  quantity: 3
};

// map에 함수를 하나만 전달하여 자동 부분 적용

indongyoo

const http = require('http');
const url = require('url');
const querystring = require('querystring');

const getBody = req => new Promise(function(resolve) {
  let body = '';
  req.on('data', data => body += data);
  req.on('end', _ => resolve(
    req.headers['content-type'] === 'application/json' ?
      JSON.parse(body) : querystring.parse(body)

indongyoo

const { map, some } = Functional;

const f13 = pipe(
  map(a => new Promise(function(resolve) {
    resolve(a + 5);
  })),
  some(a => a > 10), // <- map에서 비동기를 제어한 후 some에 [10, 15, 20] 전달
  console.log
).error(
  e => console.log('err --->', e)

indongyoo

const f12 = pipe(
  arr => arr.map(a => new Promise(function(resolve, reject) {
    reject(`${a} reject!`);
  })),
  arr => arr.some(a => a > 10), // <-- 여기에 [Promise, Promise, Promise] 가 내려가고
  console.log // <-- false가 찍힙니다.
).error(
  e => console.log('err --->', e)
);

indongyoo

const f10 = pipe(
  arr => arr.map(a => a + 5),
  arr => arr.some(a => a > 10),
  console.log
).error(
  e => console.log('err --->', e)
);

f10([5, 10, 15]); // true

indongyoo

pipe(
  a => { throw 'ho' },
  a => 10
).error(
  _ => console.log('에러!')
).complete(
  a => console.log('성공 - ', a)
) ();
// 에러!

indongyoo

pipe(
  a => asdasdasd,
  a => 10
)
.error(e => match(e)
  .case(e => e instanceof ReferenceError) (
    _ => console.log('ref 에러!')
  ).else (
    _ => console.log('에러!')
  )