urls.md

URLs
====

The URL _it self_ is a relatively uninteresting, yet very a important notion for the design of Redox. What is the interesting part is what it represents.

The URL
-------

In short, an URL is an identifier of a resource. They contain two parts:

1. The scheme part. This part represents, the "receiver", i.e. what scheme will handle the (F)OPEN call. This can be any arbitrary UTF-8 string, and will often simply be the name of your protocol.

2. The reference part. This part represents the "payload" of the URL, namely what the URL refer to. Consider `file`, as an example. An URL starting with `file:` simply has a reference being a path to a file. The reference can be any arbitrary byte string. The parsing, interpretation, and storage of the reference is left to the scheme. For this reason, it is not required to be a tree-like structure.

So, the string representation of an URL looks like:

```
[scheme]:[reference]
```

Note that `//` is not required, for convenience.

Opening an URL
--------------

URLs can be opened, yielding _schemes_, which can be opened to resources, which can be read, written and (for some resources) seeked (the are some more operations, these are described later on).I

For compatibility reasons, we use a file API similar to the Rust standard libraries for opening URLs:

```
use std::fs::OpenOptions;
use std::io::prelude::*;


fn main() {
    // Let's read from a TCP stream
    let tcp = OpenOptions::new()
                .read(true) // readable
                .write(true) // writable
                .open("tcp:0.0.0.0");
}
```

> TODO: Maybe do something with the tcp stream. Ping-pong?

> TODO: The terminology may be somewhat confusing for the reader.