Nom error

nom.rs

use crate::Response;

use nom::IResult;
use nom::character::complete::{char, anychar};
use nom::bytes::complete::take;
use nom::bytes::complete::take_until;
use nom::bytes::complete::take_till;
use nom::multi::many_till;
use nom::combinator::eof;
use nom::sequence::pair;
use nom::branch::alt;
use nom::Err;

fn parse_message(content: &[u8]) -> Response {
    // type annotations needed

    // cannot infer type for type parameter `E` declared on the function `pair`
    
    // note: cannot satisfy `_: nom::error::ParseError<&[u8]>`
    // help: consider specifying the type arguments in the function call: `::<I, O1, O2, E, F, G>`
    let memory = pair(char('m'), many_till(anychar, eof));
    //           ^^^^ error
    let last_memory = pair(char('l'), many_till(anychar, eof));
    let message = alt((
        memory,
        last_memory,
    ));
    // (
    //     &[u8],
    //     (
    //         char,
    //         (std::vec::Vec<char>, &[u8])
    //     )
    // )
    let x = message(content).unwrap();
    let response = match x.1.0 {
        'm' => {
            Response::ReadMemory(x.1.1.0.into_iter().map(|c| c as u8).collect())
        }
        'l' => {
            Response::LastReadMemory(x.1.1.0.into_iter().map(|c| c as u8).collect())
        }
    };
    // let y: () = 
    response
}