updated clear () to clear the tracer screen

[duaraghav8]

I've inserted 1 line in the clear () function in tracer.js in order to perform the clearing of screen upon calling tracer._clear ()
If this wasn't the intended behavior, then please ignore this request

[64json]

I intended _clear method in Tracer to clear just the visualizing module, not the logs in the tracer tab.
It is my bad that I didn't put comments beside methods.
I'm planning to move those printing methods into separate tracer, e.g. LogTracer.

[duaraghav8]

Oh ok.
Also, there's one more thing I was thinking about.
We need a way for tracer to notify us once it has performed a particular function.

If we want to execute a statement right after the tracer has finished doing something, we currently cannot do it.

Take this simple code for example:

var tracer = new Array1DTracer ();
var array = [10, 20, 30, 90, 829];

tracer._setData (array);
for (var i = 0; i < array.length; i++) {
    tracer._select (i);
}

var newArray = [4,6,2,4,6,3,7];
tracer._setData (newArray);

One would expect that the screen displays the first array, selects all the items on-by-one, THEN changes the view to the newArray.
But instead, because of how tracers are implemented internally, it shows the first array. The moment we click "Run", it immediately changes the view to the newArray and selects items in the newArray.

This means we need the last tracer._select () to notify us that this action has been performed.
I can think of 3 ways to do this:

1. use Callback with tracer functions like:

tracer._select (i, function () { console.log ('this comes after select'); });

1. use Promises with tracer functions like:

tracer.select (i).then (function () { console.log ('this comes after select'); });

1. Dispatch events from tracer functions like:

document.addEventListener ('cleared', function () { console.log ('screen cleared'); });
tracer._clear ();

What do you think?

[64json]

Mhm, this might be a significant issue.
I guess I can fix it without callback functions.
I will let you know after I look over it again.
Thanks!