ES6 based solution for Advent Of Code, Day 19

advent-of-code-19-solution-es6.js

'use strict'

var fs = require('fs')
var inFile = '19.txt'

var content = fs.readFileSync(inFile, {encoding: 'UTF-8'})
var lines = content.split('\n')
var text = lines[lines.length -1]
var termLines = lines.slice(0,-1).filter(String)
var permutations = []

function findAllIndexOf(text, term){
	let match
	let matches = []
	let regexp = new RegExp(term, 'g')
	while ((match = regexp.exec(text)) != null) {
	  matches.push(match.index)
	}
	return matches
}

function produce(text, term, product, index){
	return text.substr(0, index) + product + text.substr(index + term.length)
}

function unique(array){
	return [...new Set(array)]
}

for(var line of termLines){
	let [term, _, product] = line.split(' ')
	let indizes = findAllIndexOf(text, term)
	let linePermutations = indizes
		.map(produce.bind(null, text, term, product))

	permutations.push(...linePermutations)
}
permutations = unique(permutations)


console.log(permutations.length)
// run with `node --harmony_destructuring 19.js`