emitter 增强 多条件触发

;(function(global ,undefined){
    var evts = {}
        ,onceTag = '__event_once'
    function emit(event ){
        var args = util.toArray(arguments , 1)
        if (!(event in evts)) return
        var _dels = []
        for (var i = 0 , j = evts[event].length ; i < j ;i ++){
            var cbk = evts[event][i]
            if (!cbk) return
            cbk.apply(null , args)
            if (cbk[onceTag])  { evts[event][i] = null ; _dels.push[i]}
        }
        for (var i = _dels.length -1 ; i>=0 ; i--) evts[event].splice(_dels[i] , 1)
    }

    function addMultiCon(event , listener){
        var once = true
        event.sort()
        addListener(event.join('|') , listener , once)
        var eventBubbles = []
        function tinOpener(evt){
            eventBubbles.push(evt)
            if (eventBubbles.length >=  event.length) {
                eventBubbles.sort()
                emit(eventBubbles.join('|'))
            }
        }

        for (var i = 0 ; i < event.length;i ++){
            addListener(event[i] , tinOpener.bind(null, event[i]) , once)
        }
    }

    function addListener(event , listener , once){
        if (util.isArray(event)) return addMultiCon(event , listener)


        if (!(event in evts)) evts[event] = []
        if (once) listener[onceTag] = true
        evts[event].push(listener)
    }

    function removeListener(event, listener){
        if (!listener) {
            delete evts[event]
            return
        }
        for (var i = 0 , j = evts[event].length ; i < j ;i ++){
            if (evts[event][i] === listener) {  evts[event].splice(i, 1) ; break}
        }
    }

    function listeners(event){
        return evts[event]
    }
    global.emitter = {
        on : addListener
        ,once : function(event , listener){
                addListener(event , listener , true)
                }
        ,emit : emit
        ,listeners : listeners
    }
})(this)

 function toArray(colletions ,offset){
    return Array.prototype.slice.call(colletions , offset || 0)
}

emitter.on(['test','test2'] , function(){
   console.log('test is fired')
})

emitter.emit('test')

emitter.emit('test2')