Example of creating a Gist using Python

init-deep-dive_rust-proc-macro.rs

// Parse the annotated function
    let input_fn: ItemFn = parse_macro_input!(item as ItemFn);

    let vis   = &input_fn.vis;
    let sig   = &input_fn.sig;
    let body  = &input_fn.block;
    let ident = &input_fn.sig.ident;

    let print_ret = if log_ret {
        quote! {
            println!("Return value from {}: {:?}", stringify!(#ident), &__ret);
        }
    } else {
        quote! {}
    };


    // Splice everything together
    quote! {
        #vis #sig {
            println!("Entering {}", stringify!(#ident));
            #timer_start

            // Execute the user’s body, capture the return value.
            let __ret = (|| #body)();

            #print_ret
            #timer_end

            __ret
        }
    }.into()