简单的函数式回调链构造器

simple-async.coffee

#!/usr/bin/env coffee

module.exports = SimpleAsync = (funcs...) ->
  callback = (args...) ->
    funcs.shift()? args..., callback
    return
  inner = (argsOrFuncs...) ->
    if typeof argsOrFuncs[0] is 'function'
      funcs.push argsOrFuncs...
      inner
    else
      callback argsOrFuncs...
      return

if require.main is module
  func1 = (id, leave, callback) ->
    console.log "id #{id} in func1 leave #{leave}"
    setTimeout callback, 100, id, 'func1'
  func2 = (id, leave, callback) ->
    console.log "id #{id} in func2 leave #{leave}"
    setTimeout callback, 200, id, 'func2'
  func3 = (id, leave, callback) ->
    console.log "id #{id} in func3 leave #{leave}"
    setTimeout callback, 300, id, 'func3'

  SimpleAsync(func1)(func2, func3)(0, 'none')
  SimpleAsync(func3, func2)(func2, func1)(1, 'none')