use ignore::gitignore::Gitignore;use std::{ffi::OsStr, path::Path, sync::Arc}; #[derive(Debug)]pub enum IgnoreStack {    None,    Some {        abs_base_path: Arc<Path>,        ignore: Arc<Gitignore>,        parent: Arc<IgnoreStack>,    },    All,} impl IgnoreStack {    pub fn none() -> Arc<Self> {        Arc::new(Self::None)    }     pub fn all() -> Arc<Self> {        Arc::new(Self::All)    }     pub fn append(self: Arc<Self>, abs_base_path: Arc<Path>, ignore: Arc<Gitignore>) -> Arc<Self> {        match self.as_ref() {            IgnoreStack::All => self,            _ => Arc::new(Self::Some {                abs_base_path,                ignore,                parent: self,            }),        }    }     pub fn is_abs_path_ignored(&self, abs_path: &Path, is_dir: bool) -> bool {        if is_dir && abs_path.file_name() == Some(OsStr::new(".git")) {            return true;        }         match self {            Self::None => false,            Self::All => true,            Self::Some {                abs_base_path,                ignore,                parent: prev,            } => match ignore.matched(abs_path.strip_prefix(abs_base_path).unwrap(), is_dir) {                ignore::Match::None => prev.is_abs_path_ignored(abs_path, is_dir),                ignore::Match::Ignore(_) => true,                ignore::Match::Whitelist(_) => false,            },        }    }}