Textwire Usage

How do I use Textwire directives that start with @ symbol?

Textwire has several directives that you can use anywhere directly in your text files except for {{ }} curly braces. Here is the example of @if directive:

<div>
    @if(isFast)
        <b>Can run</b>
    @else
        <b>Can't run</b>
    @end
</div>