use std::any::Any;
use std::ops::Range;

struct Message { source: String }

trait Command {
    fn uppercase_name(&self) -> &str;
    fn from_message(msg: &Message) -> Self;
    fn to_message(&self) -> Message;
}

macro_rules! command {
    ($name: ident = $upper: expr {
        $($field: ident),*
        from_message: $param: ident -> $from: block
        to_message: $to: block
    }) => (
        pub struct $name {
            pub source: String,
            $($field: Range<u16>),*
        }

        impl $name {
            $(pub fn $field(&self) -> &str {
                &self.source[self.$field.start as usize..self.$field.end as usize]
            })*
        }

        impl Command for $name {
            fn uppercase_name(&self) -> &str { $upper }
            fn from_message($param: &Message) -> $name { $from }
            fn to_message(&self) -> Message { $to }
        }
    )
}

command! {
    PrivMsg = "PRIVMSG" {
        to, content
    }
}


fn main() {}