use crate::{encode, Channel, ERR_PREFIX};use bstr::BStr;use std::io; #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub enum Borrowed<'a> {    Data(&'a [u8]),    Flush,    Delimiter,    ResponseEnd,} impl<'a> Borrowed<'a> {    pub fn to_write(&self, out: impl io::Write) -> Result<usize, encode::Error> {        match self {            Borrowed::Data(d) => encode::data_to_write(d, out),            Borrowed::Flush => encode::flush_to_write(out).map_err(Into::into),            Borrowed::Delimiter => encode::delim_to_write(out).map_err(Into::into),            Borrowed::ResponseEnd => encode::response_end_to_write(out).map_err(Into::into),        }    }     pub fn as_slice(&self) -> Option<&[u8]> {        match self {            Borrowed::Data(d) => Some(d),            Borrowed::Flush | Borrowed::Delimiter | Borrowed::ResponseEnd => None,        }    }    pub fn as_bstr(&self) -> Option<&BStr> {        self.as_slice().map(Into::into)    }    pub fn to_error(&self) -> Option<Error> {        self.as_slice().map(Error)    }    pub fn check_error(&self) -> Option<Error> {        self.as_slice().and_then(|data| {            if data.len() >= ERR_PREFIX.len() && &data[..ERR_PREFIX.len()] == ERR_PREFIX {                Some(Error(&data[ERR_PREFIX.len()..]))            } else {                None            }        })    }    pub fn to_text(&self) -> Option<Text> {        self.as_slice().map(Into::into)    }    pub fn to_band(&self, kind: Channel) -> Option<Band> {        self.as_slice().map(|d| match kind {            Channel::Data => Band::Data(d),            Channel::Progress => Band::Progress(d),            Channel::Error => Band::Error(d),        })    }    /// Decode the band of the line, or panic if it is not actually a side-band line    pub fn decode_band(&self) -> Result<Band, DecodeBandError> {        let d = self.as_slice().ok_or(DecodeBandError::NonDataLine)?;        Ok(match d[0] {            1 => Band::Data(&d[1..]),            2 => Band::Progress(&d[1..]),            3 => Band::Error(&d[1..]),            band => return Err(DecodeBandError::InvalidSideBand(band)),        })    }} use quick_error::quick_error;quick_error! {    #[derive(Debug)]    pub enum DecodeBandError {        InvalidSideBand(band: u8) {            display("attempt to decode a non-side channel line or input was malformed: {}", band)        }        NonDataLine {            display("attempt to decode a non-data line into a side-channel band")        }    }} #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub struct Error<'a>(pub &'a [u8]); impl<'a> Error<'a> {    pub fn to_write(&self, out: impl io::Write) -> Result<usize, encode::Error> {        encode::error_to_write(self.0, out)    }} #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub struct Text<'a>(pub &'a [u8]); impl<'a> From<&'a [u8]> for Text<'a> {    fn from(d: &'a [u8]) -> Self {        let d = if d[d.len() - 1] == b'\n' { &d[..d.len() - 1] } else { d };        Text(d)    }} impl<'a> Text<'a> {    pub fn to_write(&self, out: impl io::Write) -> Result<usize, encode::Error> {        encode::text_to_write(self.0, out)    }} #[derive(PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]pub enum Band<'a> {    Data(&'a [u8]),    Progress(&'a [u8]),    Error(&'a [u8]),} impl<'a> Band<'a> {    pub fn to_write(&self, out: impl io::Write) -> Result<usize, encode::Error> {        match self {            Band::Data(d) => encode::band_to_write(Channel::Data, d, out),            Band::Progress(d) => encode::band_to_write(Channel::Progress, d, out),            Band::Error(d) => encode::band_to_write(Channel::Error, d, out),        }    }}