Common Javascript patterns translated into their Coffeescript equivalents for reference.

Javascript patterns -> Coffeescript

# the not not operator
# equivalent in js:
# if (!!farts) { alert("many " + farts); }

alert "many " + farts  unless not farts



# Self invoking anonymous function
do -> 
 return alert('anonymous foobar')



# Self invoking *named* function
# notice it executes twice --
# once when it self-invoked (with no args)

do f = ->
    return alert('foo ' + arguments[0])

# ...and again only this time with an arg:

f('bar')



# Syntax for singleton module pattern
# The coffeescript version seems a little obscure

x = (->
  x = ->
    alert "i am x"

  y = ->
    alert arguments[0]
  
  z = ->
    alert "i am z, z is private!"

  x: x
  y: y
)()

# both x.y and x.x were returned by singleton and lose their 
# privacy in the last two lines of module above

x.y "hello,"
x.x()



# Instantiate an object and give it a direct property (fart)
# and then a prototypal property (foo) that returns direct property fart

obj = {}
obj.fart = "stank"
obj::foo = (cheeseplate) ->  
  return false unless not cheeseplate  
  @fart  # foo() returns fart()