/**
 * please install lodash on file path
 * The following example should not be confused with curring or _.chain.
 * It is for understanding the es6 proposal-pipeline-operator only.
 */



const _ = require('lodash');
const double = n => n*2;
const increment = n => n+1;


// without chaining

var result =  double(increment(double(10)));

console.log(result, '// without chain')

let a = double(10); //20
let b = increment(a); //21
var result = double(b); //42

console.log(a, b, result, '// without chain, intermediate values')


// with lodash chain

_.mixin({'double': double, 'increment': increment});


const lodashResult = _(10).double().increment().double().value();

console.log(lodashResult, '//lodash chain');

// with lodash flow

const doubleIncrementDouble = _.flow([double, increment, double]);

var flowResult = doubleIncrementDouble(10) //42

console.log(flowResult, '//lodash flow')


// es5 pipe

var pipe = function (functionList) {
  return function (data) {
    return functionList.reduce(function(value, func) {
      return func(value)
    }, data);
  }
}


const es5Result = pipe([double, increment, double])(10);

console.log(es5Result, '// es5 pipe');


// es6 pipeline operator

// const es6Result = 10 |> double |> increment |> double;