All right. Infinite loops, those are no fun at all.

Let's see some examples.

So this should write out 120 and then true.

We get the same set of commands now being read from the saved commands variable.

Now we'd know if it's safe to evaluate a web page.

So typically, programs are very big and accept an infinite set of inputs.

This is the first step towards our crawler, which will crawl a set of webpages, finding all of the links that can be found from a seed page.

Here's one for HTML, and here's another one for JavaScript.

Another super common kind of tag is the anchor tag, which is used to add hyperlinks to webpages.

Let's see how things are going towards that goal.

Here I've typed it out.

This function call tells it which string to break up.

Interface Traffic

Traffic

Networks are all about abstraction.

Let's go and see Pex in action.

What we have built so far is a web crawler.

So for Question 1, we want to see that you understand how web pages are constructed and what a web crawler will do.

Traffic Notifications

Let me show you a more complicated example. We'll see how it plays out in real life.

Total traffic

Google made MapReduce famous building their indices for the web.

like this string containing (55).

In each item, like in the unordered list is defined with an LI tag.

You have to tell us both the type of the tag and also any arguments it might have.

But remember, that HTML can be a collection of elements rather than just 1.

Or it could be forums.udacity.com, which also has this vulnerability in it.

So it doesn't look kind of ugly and black and white.

You can see it's running on appspot.com, which is Google App Engine's domain by default.

It should look something like this. Here's the front page of a wiki.

Let's create a word processor that's just a word processor

Well, we've talked quite a bit about interpretation.

Incoming traffic only

In the real world, performance matters.

Their servers are probably on fire, because it's Twitter.

This is the recorded commands, namely open, save, and quit.

And now what we want to do is use these regular expressions, together these token definitions to break up a Web page.

Incoming traffic

Outgoing traffic

Incoming traffic

Outgoing traffic

Strangely many spammers believe if you write things in all caps you'll pay more attention to it.

Regular expressions are going to allow us to make sense of this type of data and also process it when we see it on web pages.

This is really nutso. This is not the ideal way of doing things.

This is an anchor tag, making a link to Google.