Lodash Chain Flow

lodash-chain-flow.markdown

Lodash Chain Flow

examples and performance testing of imperative, and Lodash Chain and Flow methods

A Pen by Vlad Bezden on CodePen.

License.

script.js

'use strict'
console.clear()

const fp = _.noConflict()

const add = (a, b) => a + b
const curriedAdd = fp.curry(add)
const input = _.range(1000)

function addAllUsingFlowWay(fn, arr) {
    const nestedLoop = (x) => _.map(x, (v) => x.map(v2 => fn(v, v2)))

    return _.flow([
        nestedLoop,
        _.flatten,
        fp.reduce(_.add, 0)
    ])(arr)
}

function addAllUsingChainWay(fn, arr) {
    return _
        .chain(arr)
        .map(x => arr.map(y => fn(x, y)))
        .flatten()
        .reduce((acc, cur) => acc + cur)
        .value()
}

function addAllImprerativeWay(fn, arr) {
    let result = 0
    for (let i = 0; i < arr.length; i++) {
        for (let j = 0; j < arr.length; j++) {
            result += fn(arr[i], arr[j])
        }
    }
    return result
}

function performanceCalc(fn, ...params) {
    const start = +new Date()
    const result = fn(...params)
    const end = +new Date()

    console.log(`Result: ${result}. Execution Time: ${end - start} ms`)
}

console.log('------- Imperative Way -------')
performanceCalc(addAllImprerativeWay, add, input)
performanceCalc(addAllImprerativeWay, curriedAdd, input)

console.log('------- Flow Way -------')
performanceCalc(addAllUsingFlowWay, add, input)
performanceCalc(addAllUsingFlowWay, curriedAdd, input)

console.log('------- Chain Way -------')
performanceCalc(addAllUsingChainWay, add, input)
performanceCalc(addAllUsingChainWay, curriedAdd, input)

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.13.1/lodash.min.js"></script>
<script src="https://cdn.jsdelivr.net/lodash/4.14.1/lodash.fp.min.js"></script>