# Playpen

The Rust Playpen is a way to experiment with Rust code through a web interface. This project is now commonly referred to as Rust Playground.

## Using it with `mdbook`

In `mdbook`, you can make code examples playable and editable.

    fn main() {
        println!("Hello World!");
    }

This allows the reader to both run your code sample, but also modify and tweak it. The key here is the adding the word `editable` to your codefence block separated by a comma.

    ```rust,editable
    //...place your code here
    ```

Additionally, you can add `ignore` if you want `mdbook` to skip your code when it builds and tests.

    ```rust,editable,ignore
    //...place your code here
    ```

## Using it with docs

You may have noticed in some of the official Rust docs a button that says "Run", which opens the code sample up in a new tab in Rust Playground. This feature is enabled if you use the #[doc] attribute called `html_playground_url`.

### See also:

- The Rust Playground
- The next-gen playpen
- The rustdoc Book