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Moving to ES6 from CoffeeScript

I fell in love with CoffeeScript a couple of years ago. Javascript has always seemed something of an interesting curiosity to me and I was happy to see the meteoric rise of Node.js, but coming from a background of Python I really preferred a cleaner syntax.

In any fast moving community it is inevitable that things will change, and so today we see a big shift toward ES6, the new version of Javascript. It incorporates a handful of the nicer features from CoffeeScript and is usable today through tools like Babel. Here are some of my thoughts and issues on moving away from CoffeeScript in favor of ES6.

While reading I suggest keeping open a tab to Babel's learning ES6 page. The examples there are great.

Punctuation

Holy punctuation, Batman! Say goodbye to your whitespace and hello to parenthesis, curly braces, and semicolons again. Even with the advanced ES6 syntax you'll find yourself writing a lot more punctuatio

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interface IMessage {
    name: string;
}

function itemFn(pipIn: string[]) {
    return pipIn;
}

function baseFn(pipIn: string) {
    return [pipIn];

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var R = require('ramda');

var data = [
  {it: 'item2', signal: 'update', select: true},
  {it: 'item1', signal: 'update', select: false}
]

console.log(R.contains({it: 'item2', signal: 'update', select: true}, data));

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TypeScript and currying

In functional programming you often want to apply a function partly. A simple example is a function add. It would be nice if we could use add like:

var res2 = add(1, 3); // => 4

var add10To = add(10);
var res = add10To(5); // => 15

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Typescript and mapping

Map takes a function and maps the content of a list to another list of the same length. We want to double the numbers in a list, using the function doubler

function doubler(x) {
    return x*2;
}

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var R = require('ramda').installTo(this)

var a = {}
var b = {y: a}
var c = {z: b}
a.x = c


var refFrom = []
var refTo = []

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// circular reference
var _ = require('lodash')

var c = {x:2}
var a = {x:3, c: c}
var b = {x:1, z: a}
c.p = b

var a1 = _.cloneDeep(a)
b.x = 5

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var R = require('ramda');

function Maybe(x) {
  if (!(this instanceof Maybe)) {
    return new Maybe(x);
  }
  this.value = x;
}

Maybe.of = function(x) {

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var R = require('ramda');

function Maybe(x) {
  if (!(this instanceof Maybe)) {
    return new Maybe(x);
  }
  this.value = x;
}

Maybe.of = function(x) {