fncli

An attribute macro to simplify writing simple command line applications.

Example

```rust

[fncli::cli]

fn main(a: i32, b: i32) { println!("{}", a + b); } ```

bash session $ cargo run 1 2 3

bash session $ cargo run 1 missing argument `b: i32`

bash session $ cargo run 1 2 3 too many arguments (expected 2 arguments)

bash session $ cargo run 1 a failed to parse argument `b: i32`: ParseIntError { kind: InvalidDigit }

For a more complete example, see the time elapsed example.

How It Works

```rust fn main() { let (a, b) = { let mut args = std::env::args().skip(1);

    let tuple = (
        i32::from_str(&args.next().expect("missing argument `a: i32`"))
            .expect("failed to parse argument `a: i32`"),
        i32::from_str(&args.next().expect("missing argument `a: i32`"))
            .expect("failed to parse argument `b: i32`"),
    );

    if args.next().is_some() {
        panic!("too many arguments (expected 2 arguments)");
    }

    tuple
};

{
    println!("{}", a + b);
}

} ```

The generated code is very simple, and not too different from how one would write the code by hand.