With parameter binding, the parameters of task function are automatically pulled from container, options or arguments.

example:

$app->task(function(\PDO $db, array $args) {
    // $db will be pulled from container
    // equivalent to
    // /** @var \PDO $db */
    // $db = $this->db;
});

For $options and $arguments which is the parameters for task prior to 1.5.0, there must be a special rule for them.

• $options and $opts are reserved argument for array $options
• $arguments and $args are reserved argument for array $arguments
• $context are reserved argument for Context $context
• It's possible to specify those should be array or Hash or whatever classes accept array to its constructor. The default is array.