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: highlight.rs
    path of file: ./repos/ox/src
    
    the code of the file until where you have to start completion: // Highlight.rs - For syntax highlighting
use crate::config::{Reader, TokenType};
use std::collections::HashMap;
use unicode_width::
    
fn multi_to_single(doc: &str, m: &regex::Match) -> ((usize, usize), (usize, usize)) {
    // Multiline tokens to single line tokens
    let b = bounds(&m, &doc);
    let start_y = doc[..m.start()].matches('\n').count();
    let end_y = doc[..m.end()].matches('\n').count();
    let start_x = b.0
        - UnicodeWidthStr::width(&doc.split('\n').take(start_y).collect::<Vec<_>>().join("\n")[..]);
    let end_x = b.1
        - UnicodeWidthStr::width(&doc.split('\n').take(end_y).collect::<Vec<_>>().join("\n")[..]);
    ((start_x, start_y), (end_x, end_y))
}