$ whois coffeescript

CoffeeScript

first released in 2009 · by Jeremy Ashkenas

$ guessprog --inspect coffeescript

year: 2009
paradigm: multi paradigm
family: other
memory: automatic gc
binding: dynamic
safety: weak

COFFEESCRIPT(7)

AUTHORS: Jeremy Ashkenas
HISTORY: Jeremy Ashkenas, also the author of Backbone.js and Underscore.js, started CoffeeScript in late 2009 as "a little language that compiles into JavaScript". Borrowing from Ruby and Python, it replaced braces with significant indentation and added arrow functions, classes, comprehensions, string interpolation and destructuring. The compiler was first written in Ruby and soon rewritten in CoffeeScript. Many of its ideas, such as arrow functions, classes and destructuring, later made their way into JavaScript with ES2015.
USAGE: Largely legacy today. It was very popular in the early 2010s, shipping by default with Ruby on Rails 3.1, but most projects have since moved to modern JavaScript or TypeScript.
SEE ALSO: CoffeeScript on Wikipedia ↗

$ cat greeter.coffee

square = (x) -> x * x

evens = (square n for n in [1..10] when n % 2 is 0)
console.log evens   # [4, 16, 36, 64, 100]

class Greeter
  constructor: (@name) ->
  greet: -> "Hello, #{@name ? 'stranger'}!"

console.log new Greeter("Coffee").greet()
console.log new Greeter().greet()