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: parse.rs
    path of file: ./repos/phaser/phaser/vendor/proc-macro2/src
    
    the code of the file until where you have to start completion: use crate::fallback::{
    is_ident_continue, is_ident_start, Group, LexError, Literal, Span, TokenStream,
};
use crate::{Delimiter, Punct, Spacing, TokenTree};
use std::char;
use std::str::{Bytes, CharIndices, Chars};

#[derive(Copy, Clone, Eq, PartialEq)]
pub(crate) struct Cursor<'a> {
    pub rest: &'a str,
    #[cfg(span_locations)]
    pub off: u32,
}

impl<'a> Cursor<'a> {
    fn advance(&self, bytes: usize) -> Cursor<'a> {
        let (_front, rest) = self.rest.split_at(bytes);
        Cursor {
            rest,
            #[cfg(span_locations)]
            off: self.off + _front.chars().count() as u32,
        }
    }

    fn starts_with(&self, s: &str) -> bool {
        self.rest.starts_with(s)
    }

    fn is_empty(&self) -> bool {
        self.rest.is_empty()
    }

    fn len(&self) -> usize {
        self.rest.len()
    }

    fn as_bytes(&self) -> &'a [u8] {
        self.rest.as_bytes()
    }

    fn bytes(&self) -> Bytes<'a> {
        self.rest.bytes()
    }

    fn chars(&self) -> Chars<'a> {
        self.rest.chars()
    }

    fn char_indices(&sel
    
fn cooked_byte_string(mut input: Cursor) -> Result<Cursor, Reject> {
    let mut bytes = input.bytes().enumerate();
    while let Some((offset, b)) = bytes.next() {
        match b {
            b'"' => {
                let input = input.advance(offset + 1);
                return Ok(literal_suffix(input));
            }
            b'\r' => match bytes.next() {
                Some((_, b'\n')) => {}
                _ => break,
            },
            b'\\' => match bytes.next() {
                Some((_, b'x')) => {
                    if !backslash_x_byte(&mut bytes) {
                        break;
                    }
                }
                Some((_, b'n')) | Some((_, b'r')) | Some((_, b't')) | Some((_, b'\\'))
                | Some((_, b'0')) | Some((_, b'\'')) | Some((_, b'"')) => {}
                Some((newline, b @ b'\n')) | Some((newline, b @ b'\r')) => {
                    let mut last = b as char;
                    let rest = input.advance(newline + 1);
                    let mut chars = rest.char_indices();
                    loop {
                        if last == '\r' && chars.next().map_or(true, |(_, ch)| ch != '\n') {
                            return Err(Reject);
                        }
                        match chars.next() {
                            Some((_, ch)) if ch.is_whitespace() => last = ch,
                            Some((offset, _)) => {
                                input = rest.advance(offset);
                                bytes = input.bytes().enumerate();
                                break;
                            }
                            None => return Err(Reject),
                        }
                    }
                }
                _ => break,
            },
            b if b < 0x80 => {}
            _ => break,
        }
    }
    Err(Reject)
}