use std::{fs, io, path, pin};

pub fn open_file(path: &path::Path) -> io::Result<Option<fs::File>> {
    match fs::File::open(path) {
        Ok(file) => Ok(Some(file)),
        Err(err) => match err.kind() {
            io::ErrorKind::NotFound => Ok(None),
            _ => Err(err),
        },
    }
}

pub type BoxByteStream = futures::stream::BoxStream<'static, io::Result<Vec<u8>>>;

pub type BoxFuture<'a, O> = pin::Pin<Box<dyn futures::Future<Output = O> + Send + 'a>>;