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: command.rs
    path of file: ./repos/escanor/src/bin/server
    
    the code of the file until where you have to start completion: extern crate regex;

use crate::{db, printer};
use crate::error;

use crate::error::SyntaxError;
use crate::tokenizer;
use crate::syntax_analyzer;


use crate::unit_conv::Units;
use c
    
pub fn compile(buf: &[u8]) -> Result<Box<dyn Command>, error::SyntaxError> {
    let _empty_string = String::new();
    let first_char = buf[0] as char;
    return match first_char {
        '*' | '$' | '+' => {
            compile_resp(buf)
        }
        _ => {
            compile_raw(buf)
        }
    };
}