Function entry 

pub fn entry(
    input: &str,
    body: impl FnOnce(TokenStream) -> TokenStream + UnwindSafe,
) -> Output

The entry for charm that handle input/output converions, and panics handling.

check out:

• [panic::run_and_catch] for panic handling.
• [parse_input] for input parsing.
• [collect_outputs] for output serialization.