Named arguments in CoffeeScript for (a)sync funs

1.ref.md

http://ivanzuzak.info/2009/08/09/named-arguments-in-javascript.html

http://jamie-wong.com/2011/11/28/name-your-arguments/

2.named.coffee

fun = ({subject, verb}, next) ->
  # no defaults in the function definition
  subject ?= 'I'
  verb ?= 'dream'
  result = "#{subject} #{verb}"
  return next null, result  if next?
  result


# run
arg1 = 'We'
# async
fun {subject, verb: 'code'}, (err, result) -> console.log result
fun {}, (err, result) -> console.log result
# sync
result = fun {subject, verb: 'code'}
result = fun {} # mandatory

3.positional.coffee

# required args
fun = (arg1 = 'I', arg2 = 'dream', next) ->
  # same body as the named-args variant, except for the defaults
  result = "#{subject} #{verb}"
  return next null, result  if next?
  result

# optional args ?
###
you can do it, but it's either ugly, either impossible
because you cannot make more than 1-2 args optional, especially if you want to be positionally flexible
###


# run
subject = 'We'
# async
fun 'We', 'code', (err, result) -> console.log result
fun subject, 'code', (err, result) -> console.log result
# sync
result = fun subject, 'code'
result = fun subject, verb