You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lib.rs
    path of file: ./repos/tiny/crates/term_input_macros/src
    
    the code of the file until where you have to start completion: mod syntax;
mod tree;

use proc_macro::TokenStream;
use quote::quote;
use syntax::Input;

#[proc_macro]
pub fn byte_seq_parser(input
    
pub fn byte_seq_parser(input: TokenStream) -> TokenStream {
    let Input {
        fn_name,
        fn_return_type,
        rules,
    } = syn::parse_macro_input!(input as syntax::Input);

    let fn_body = tree::build_decision_tree(rules);
    quote!(fn #fn_name(buf: &[u8]) -> Option<(#fn_return_type, usize)> {
        #fn_body
    })
    .into()
}