catch.js

w = (func, cb, args) ->
	errHandler = (err) ->
		dir 'ERR', err
	try
		promise.when func.apply(this, args), cb, errHandler
	catch err
		errHandler err

w1 = (func, cb, args) ->
	errHandler = (err) ->
		if err not instanceof Error
			err = new Error err # TODO: check err type
		cb err
	try
		promise.when func.apply(this, args), cb, errHandler
	catch err
		errHandler err

w2 = (func, cb, eb, args) ->
	try
		promise.when func.apply(this, args), cb, eb
	catch err
		eb err