module main

pub struct MyError implements IError {
pub:
    msg    string
    code   int
    domain int
    level  int
}

pub fn (e MyError) str() string {
    return '${e.msg} ${e.code}:${e.domain}:${e.level}'
}

pub fn (e MyError) msg() string {
    return e.msg
}

pub fn (e MyError) code() int {
    return e.code
}

fn MyError.new(msg string, code int, domain int, level int) MyError {
    return MyError{
        msg:    msg
        code:   code
        domain: domain
        level:  level
    }
}

fn foo() ! {
    return MyError.new('xxx', 1, 1, 1)
}

fn main() {
    foo() or {
        if err is MyError {
            eprintln(err)
        }
    }
}