use std::borrow::Cow; use bstr::{BStr, BString, ByteSlice}; #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub enum Kind {    /// A pattern to match paths against    Pattern(BString, crate::ignore::pattern::Mode),    /// The name of the macro to define, always a valid attribute name    Macro(BString),} mod error {    use bstr::BString;    use quick_error::quick_error;     quick_error! {        #[derive(Debug)]        pub enum Error {            PatternNegation { line_number: usize, line: BString } {                display("Line {} has a negative pattern, for literal characters use \\!: {}", line_number, line)            }            AttributeName { line_number: usize, attribute: BString } {                display("Attribute in line {} has non-ascii characters or starts with '-': {}", line_number, attribute)            }            MacroName { line_number: usize, macro_name: BString } {                display("Macro in line {} has non-ascii characters or starts with '-': {}", line_number, macro_name)            }            Unquote(err: git_quote::ansi_c::undo::Error) {                display("Could not unquote attributes line")                from()                source(err)            }        }    }}pub use error::Error; pub struct Lines<'a> {    lines: bstr::Lines<'a>,    line_no: usize,} pub struct Iter<'a> {    attrs: bstr::Fields<'a>,    line_no: usize,} impl<'a> Iter<'a> {    pub fn new(attrs: &'a BStr, line_no: usize) -> Self {        Iter {            attrs: attrs.fields(),            line_no,        }    }     fn parse_attr(&self, attr: &'a [u8]) -> Result<(&'a BStr, crate::State<'a>), Error> {        let mut tokens = attr.splitn(2, |b| *b == b'=');        let attr = tokens.next().expect("attr itself").as_bstr();        let possibly_value = tokens.next();        let (attr, state) = if attr.first() == Some(&b'-') {            (&attr[1..], crate::State::Unset)        } else if attr.first() == Some(&b'!') {            (&attr[1..], crate::State::Unspecified)        } else {            (                attr,                possibly_value                    .map(|v| crate::State::Value(v.as_bstr()))                    .unwrap_or(crate::State::Set),            )        };        Ok((check_attr(attr, self.line_no)?, state))    }} fn check_attr(attr: &BStr, line_number: usize) -> Result<&BStr, Error> {    fn attr_valid(attr: &BStr) -> bool {        if attr.first() == Some(&b'-') {            return false;        }         attr.bytes().all(|b| {            matches!(b,         b'-' | b'.' | b'_' | b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9')        })    }     attr_valid(attr).then(|| attr).ok_or_else(|| Error::AttributeName {        line_number,        attribute: attr.into(),    })} impl<'a> Iterator for Iter<'a> {    type Item = Result<(&'a BStr, crate::State<'a>), Error>;     fn next(&mut self) -> Option<Self::Item> {        let attr = self.attrs.next().filter(|a| !a.is_empty())?;        self.parse_attr(attr).into()    }} impl<'a> Lines<'a> {    pub fn new(buf: &'a [u8]) -> Self {        let bom = unicode_bom::Bom::from(buf);        Lines {            lines: buf[bom.len()..].lines(),            line_no: 0,        }    }} impl<'a> Iterator for Lines<'a> {    type Item = Result<(Kind, Iter<'a>, usize), Error>;     fn next(&mut self) -> Option<Self::Item> {        fn skip_blanks(line: &BStr) -> &BStr {            line.find_not_byteset(BLANKS).map(|pos| &line[pos..]).unwrap_or(line)        }        for line in self.lines.by_ref() {            self.line_no += 1;            let line = skip_blanks(line.into());            if line.first() == Some(&b'#') {                continue;            }            match parse_line(line, self.line_no) {                None => continue,                Some(res) => return Some(res),            }        }        None    }} fn parse_line(line: &BStr, line_number: usize) -> Option<Result<(Kind, Iter<'_>, usize), Error>> {    if line.is_empty() {        return None;    }     let (line, attrs): (Cow<'_, _>, _) = if line.starts_with(b"\"") {        let (unquoted, consumed) = match git_quote::ansi_c::undo(line) {            Ok(res) => res,            Err(err) => return Some(Err(err.into())),        };        (unquoted, &line[consumed..])    } else {        line.find_byteset(BLANKS)            .map(|pos| (line[..pos].as_bstr().into(), line[pos..].as_bstr()))            .unwrap_or((line.into(), [].as_bstr()))    };     let kind_res = match line.strip_prefix(b"[attr]") {        Some(macro_name) => check_attr(macro_name.into(), line_number)            .map(|m| Kind::Macro(m.into()))            .map_err(|err| match err {                Error::AttributeName { line_number, attribute } => Error::MacroName {                    line_number,                    macro_name: attribute,                },                _ => unreachable!("BUG: check_attr() must only return attribute errors"),            }),        None => {            let (pattern, flags) = super::ignore::parse_line(line.as_ref())?;            if flags.contains(crate::ignore::pattern::Mode::NEGATIVE) {                Err(Error::PatternNegation {                    line: line.into_owned(),                    line_number,                })            } else {                Ok(Kind::Pattern(pattern, flags))            }        }    };    let kind = match kind_res {        Ok(kind) => kind,        Err(err) => return Some(Err(err)),    };    Ok((kind, Iter::new(attrs, line_number), line_number)).into()} const BLANKS: &[u8] = b" \t\r";