Function thunder::thunderclap

pub fn thunderclap(args: TokenStream, input: TokenStream) -> TokenStream

Main macro that implements automated clap generation. This invokes ✨ magic ✨

Foremost every impl block tagged with the macro will turn into a Thunder-app. At the moment only a single Thunder app can exist in the same scope (this will change).

What a thunder app does is take every function in it's scope and turn it into a CLI handle with clap, meaning that all arguments will be mapped to the user shell as they are described in the function body.

Example

fn say_hello(name: &str, age: Option<u16>) {
    // ...
}

This function will turn into the CLI option say_hello that always takes a name parameter (which is a String) and optionally a number (which has to fit into u16!)

These conversion checks are done at run-time but functions are only called if the parameters are valid. As such, you don't have to worry :)

A more complete example

The block below defines a medium sized thunder application.

struct MyApp;

#[thunderclap]
impl MyApp {
    /// Say hello to someone on the other side
    fn say_hello(name: &str, age: Option<u16>) { /* ... */ }
     
    /// It was nice to meet you!
    fn goodybe(name: Option<&str>) { /* ... */ }
}

fn main() {
    // This starts the match execution
    MyApp::start();
}

Global variables

It's possible to declare argument parameters that can be invoked on any function and are available outside of regular context. thunder generates an argument store which you can use to get results from these global arguments.

They can be both mandatory (T) or optional (Option<T>) and are named and also have a description displayed to the user. Their names are abbreviated with --name and -n if the parameter was called name.

A small example below.

struct MyApp;

#[thunder(arg1: u32: "A small description", arg2: Option<bool>: "Optional global")]
impl MyApp {
    fn hello(name: &str) {}
}

fn main() {
    MyApp::start();
}

If you have more questions or encounter bugs, don't hesitate to contact us! PR's always welcome (we're friendly ❤️)