Javascript Pipe

gistfile1.txt

const arr = [1, 2, 3]

const sum = (a, b) => a + b

const result = arr.reduce(sum)

// console.log(result)


// arr.forEach(i => console.log(i))


const each = (f, arr) => {
  let i = 0

  while(i < arr.length) {
    f(arr[i])
    i++
  }
}

const newArr = arr.map(i => i + 10)

// console.log(newArr)

const map = (f, arr) => {
  const result = []
  each((i) => {
    result.push(f(i))
  }, arr)
  return result
}

// console.log(map((i) => i + 2, [2,3,4]))

const reduce = (f, initValue, arr) => {
  const init = arr ? initValue : initValue[0]
  arr = arr ? arr : initValue
  let result = init

  each((i) => {
    result = f(i, result)
  }, arr)
  return result
}

const reduced1 = reduce(sum, arr) // 6
const reduced2 = reduce(sum, 10, arr) // 16

console.log(reduced1)

console.log(reduced2)

const pipe = (init, ...funcs) => {
  // console.log(init)
  // console.log(funcs)

  // return funcs[2](funcs[1](funcs[0](init)))
  // let result = init
  // funcs.forEach(f => {
  //   result = f(result)
  // })
  // return result
  // return funcs.forEach((elem) => {
  //   console.log(1, elem)
  // })

  return reduce((f, result) => {
    return result = f(result)
  }, init, funcs)
}

const piped = pipe(
   10,
   (i) => i + 10,
   (i) => i * 2,
   (i) => i + 1,
  ) // 41

 console.log('* piped')
 console.log(piped)