use rlua::prelude::*;use std::{    fs,    io::{self, BufRead}};use chrono::{DateTime, Local};use diff_rs::diff;fn time_format(d: &DateTime<Local>) -> String {    d.format("%Y-%m-%d %H:%M:%S.%f %z").to_string()}fn mtime(path: &str) -> crate::Result<DateTime<Local>> {    Ok(DateTime::from(fs::metadata(path)?.modified()?))}fn read_file(path: &str) -> io::Result<Vec<String>> {    let file = fs::File::open(path)?;    let file = io::BufReader::new(file);    file.lines().collect()}pub fn init(lua: &Lua) -> crate::Result<()> {    let module = lua.create_table()?;    module.set("compare_strings", lua.create_function( |_, (left, right): (String, String)| {        let prefix = vec![            format!("--- a\t{}", time_format(&Local::now())),            format!("+++ b\t{}", time_format(&Local::now()))        ];        let diff = diff(            &left                .split("\n")                .map(str::to_owned)                .collect::<Vec<_>>(),            &right                .split("\n")                .map(str::to_owned)                .collect::<Vec<_>>(),                3            ).map_err(LuaError::external)?;                let mut res = String::new();        prefix.iter().cloned().chain(diff).for_each(|s| { res.push_str(&s); res.push('\n') });        Ok(res)    })?)?;    module.set("compare_files", lua.create_function( |_, (left, right): (String, String)| {        let prefix = vec![            format!("--- {}\t{}", &left, time_format(&mtime(&left).map_err(LuaError::external)?)),            format!("+++ {}\t{}", &right, time_format(&mtime(&right).map_err(LuaError::external)?))        ];        let left = read_file(&left).map_err(LuaError::external)?;        let right = read_file(&right).map_err(LuaError::external)?;        let diff = diff(&left, &right, 3).map_err(LuaError::external)?;        let mut res = String::new();        prefix.iter().cloned().chain(diff).for_each(|s| { res.push_str(&s); res.push('\n') });        Ok(res)    })?)?;    lua.globals().set("diff", module)?;    Ok(())}