Edit in JSFiddle

var Signal = function(a,b,c){return{s:a=[],d:function(){for(c=a.slice();b=c.pop();)b.apply(this,arguments)},r:function(c){a.splice(a.indexOf(b),1)}}}


var Something = function(){
        this.wasHere = Signal();
    
        this.move = function(){
            this.wasHere.d('bigfoot', 'sasquatch'); // d for dispatch!
        }
        
    }

    // a slot is just a callback
    ,what = function(wasIt){
        // 'this' will be the signal obj itself
        document.getElementById( "ret" ).innerHTML 
            += 'what it was: ' 
            + wasIt + ' ' + this + '<br />';
    }

    ,scope = (function(wasIt, sas){
        // 'this' will be the global obj
        document.getElementById( "ret" ).innerHTML 
            += 'what it was: ' 
            + wasIt + ' ' + sas + ' ' + this + '<br />';
    }).bind(this)

var s = new Something();
// unfortunately, these will be executed in reverse order
s.wasHere.s.push(what);
s.wasHere.s.push(scope);
s.move(); 

<div>Expected value: <b><br />what it was: bigfoot sasquatch [object Window]<br/>what it was bigfoot [object Object]</b></div>
<div>Actual value: <br /><b id="ret"></b></div>