подозрение на монаду

async.coffee

fn = (cb) ->
  some_async_func1 arg1, (err, results) ->
    (return cb err) if err
    some_async_func2 results, (err, results2) ->
      (return cb err) if err
      some_async_func3 results2, (err, results3) ->
        cb err, results3

monaded.coffee

{cont_t, domonad, error_m, lift_sync, lift_async} = require 'libmonad'

fn = (cb) ->
  sequence = [
    lift_async(2, some_async_func1)
    lift_async(2, some_async_func2)
    lift_async(2, some_async_func3)
    ]
    
  worker_monad = cont_t error_m()
  (domonad worker_monad, sequence, arg1) ([err, result3]) ->
    cb err, result3