violet-athena

const getCharacterFrequency = string => string.split('').reduce((acc, char) => {
  const { length } = string.split(char);

  if (length > acc.frequency) {
    acc.frequency = length;
    acc.mostFrequent = char;
  }

  return acc;
}, { frequency: 0, mostFrequent: '' }).mostFrequent;

violet-athena

const findPeaks = arr => arr.reduce((result, curr, i) => {
  const prev = arr[i - 1];
  const next = arr.slice(i).find(item => item !== curr);

  if(curr > prev && curr > next) {
    result.pos.push(i);
    result.peaks.push(curr);
  }

  return result;

violet-athena

// manual implementation
const sum = ([first, ...rest]) => rest.length ? first + sum(rest) : first;

// using reduce
const sum = arr => arr.reduce((acc, el) => acc + el, 0);

violet-athena

// imperative
function fibonacci(n, first = 0, second = 1) {
  while (n !== 0) {
  	console.log(first); // side-effect
  	[n, first, second] = [n - 1, second, first + second]; // assignment
  }
}
fibonacci(10);

// functional

violet-athena

###
Original project here: https://github.com/glenjamin/node-fib ,
this is CoffeeScript rewrite of the app. Nothing more, nothing less.
###

app = require("express").createServer()
port = "3000"

fibonacci = (n, callback) ->
    inner = (n1, n2, i) ->