#![allow(non_snake_case)]
#![stable(feature = "core_char", since = "1.2.0")]
mod convert;
mod decode;
mod methods;
#[stable(feature = "try_from", since = "1.34.0")]
pub use self::convert::CharTryFromError;
#[stable(feature = "char_from_str", since = "1.20.0")]
pub use self::convert::ParseCharError;
#[stable(feature = "decode_utf16", since = "1.9.0")]
pub use self::decode::{DecodeUtf16, DecodeUtf16Error};
#[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")]
pub use self::methods::encode_utf16_raw;
#[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")]
pub use self::methods::encode_utf8_raw;
use crate::ascii;
use crate::error::Error;
use crate::escape;
use crate::fmt::{self, Write};
use crate::iter::FusedIterator;
use crate::num::NonZeroUsize;
pub(crate) use self::methods::EscapeDebugExtArgs;
const TAG_CONT: u8 = 0b1000_0000;
const TAG_TWO_B: u8 = 0b1100_0000;
const TAG_THREE_B: u8 = 0b1110_0000;
const TAG_FOUR_B: u8 = 0b1111_0000;
const MAX_ONE_B: u32 = 0x80;
const MAX_TWO_B: u32 = 0x800;
const MAX_THREE_B: u32 = 0x10000;
#[stable(feature = "rust1", since = "1.0.0")]
pub const MAX: char = char::MAX;
#[stable(feature = "decode_utf16", since = "1.9.0")]
pub const REPLACEMENT_CHARACTER: char = char::REPLACEMENT_CHARACTER;
#[stable(feature = "unicode_version", since = "1.45.0")]
pub const UNICODE_VERSION: (u8, u8, u8) = char::UNICODE_VERSION;
#[stable(feature = "decode_utf16", since = "1.9.0")]
#[inline]
pub fn decode_utf16<I: IntoIterator<Item = u16>>(iter: I) -> DecodeUtf16<I::IntoIter> {
    self::decode::decode_utf16(iter)
}
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_char_convert", since = "1.67.0")]
#[must_use]
#[inline]
pub const fn from_u32(i: u32) -> Option<char> {
    self::convert::from_u32(i)
}
#[stable(feature = "char_from_unchecked", since = "1.5.0")]
#[rustc_const_unstable(feature = "const_char_from_u32_unchecked", issue = "89259")]
#[must_use]
#[inline]
pub const unsafe fn from_u32_unchecked(i: u32) -> char {
    unsafe { self::convert::from_u32_unchecked(i) }
}
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_char_convert", since = "1.67.0")]
#[must_use]
#[inline]
pub const fn from_digit(num: u32, radix: u32) -> Option<char> {
    self::convert::from_digit(num, radix)
}
#[derive(Clone, Debug)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct EscapeUnicode(escape::EscapeIterInner<10>);
impl EscapeUnicode {
    fn new(chr: char) -> Self {
        let mut data = [ascii::Char::Null; 10];
        let range = escape::escape_unicode_into(&mut data, chr);
        Self(escape::EscapeIterInner::new(data, range))
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Iterator for EscapeUnicode {
    type Item = char;
    #[inline]
    fn next(&mut self) -> Option<char> {
        self.0.next().map(char::from)
    }
    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        let n = self.0.len();
        (n, Some(n))
    }
    #[inline]
    fn count(self) -> usize {
        self.0.len()
    }
    #[inline]
    fn last(mut self) -> Option<char> {
        self.0.next_back().map(char::from)
    }
    #[inline]
    fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
        self.0.advance_by(n)
    }
}
#[stable(feature = "exact_size_escape", since = "1.11.0")]
impl ExactSizeIterator for EscapeUnicode {
    #[inline]
    fn len(&self) -> usize {
        self.0.len()
    }
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for EscapeUnicode {}
#[stable(feature = "char_struct_display", since = "1.16.0")]
impl fmt::Display for EscapeUnicode {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(self.0.as_str())
    }
}
#[derive(Clone, Debug)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct EscapeDefault(escape::EscapeIterInner<10>);
impl EscapeDefault {
    fn printable(chr: ascii::Char) -> Self {
        let data = [chr];
        Self(escape::EscapeIterInner::from_array(data))
    }
    fn backslash(chr: ascii::Char) -> Self {
        let data = [ascii::Char::ReverseSolidus, chr];
        Self(escape::EscapeIterInner::from_array(data))
    }
    fn from_unicode(esc: EscapeUnicode) -> Self {
        Self(esc.0)
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Iterator for EscapeDefault {
    type Item = char;
    #[inline]
    fn next(&mut self) -> Option<char> {
        self.0.next().map(char::from)
    }
    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        let n = self.0.len();
        (n, Some(n))
    }
    #[inline]
    fn count(self) -> usize {
        self.0.len()
    }
    #[inline]
    fn last(mut self) -> Option<char> {
        self.0.next_back().map(char::from)
    }
    #[inline]
    fn advance_by(&mut self, n: usize) -> Result<(), NonZeroUsize> {
        self.0.advance_by(n)
    }
}
#[stable(feature = "exact_size_escape", since = "1.11.0")]
impl ExactSizeIterator for EscapeDefault {
    #[inline]
    fn len(&self) -> usize {
        self.0.len()
    }
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for EscapeDefault {}
#[stable(feature = "char_struct_display", since = "1.16.0")]
impl fmt::Display for EscapeDefault {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(self.0.as_str())
    }
}
#[stable(feature = "char_escape_debug", since = "1.20.0")]
#[derive(Clone, Debug)]
pub struct EscapeDebug(EscapeDebugInner);
#[derive(Clone, Debug)]
enum EscapeDebugInner {
    Bytes(escape::EscapeIterInner<10>),
    Char(char),
}
impl EscapeDebug {
    fn printable(chr: char) -> Self {
        Self(EscapeDebugInner::Char(chr))
    }
    fn backslash(chr: ascii::Char) -> Self {
        let data = [ascii::Char::ReverseSolidus, chr];
        let iter = escape::EscapeIterInner::from_array(data);
        Self(EscapeDebugInner::Bytes(iter))
    }
    fn from_unicode(esc: EscapeUnicode) -> Self {
        Self(EscapeDebugInner::Bytes(esc.0))
    }
    fn clear(&mut self) {
        let bytes = escape::EscapeIterInner::from_array([]);
        self.0 = EscapeDebugInner::Bytes(bytes);
    }
}
#[stable(feature = "char_escape_debug", since = "1.20.0")]
impl Iterator for EscapeDebug {
    type Item = char;
    #[inline]
    fn next(&mut self) -> Option<char> {
        match self.0 {
            EscapeDebugInner::Bytes(ref mut bytes) => bytes.next().map(char::from),
            EscapeDebugInner::Char(chr) => {
                self.clear();
                Some(chr)
            }
        }
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        let n = self.len();
        (n, Some(n))
    }
    #[inline]
    fn count(self) -> usize {
        self.len()
    }
}
#[stable(feature = "char_escape_debug", since = "1.20.0")]
impl ExactSizeIterator for EscapeDebug {
    fn len(&self) -> usize {
        match &self.0 {
            EscapeDebugInner::Bytes(bytes) => bytes.len(),
            EscapeDebugInner::Char(_) => 1,
        }
    }
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for EscapeDebug {}
#[stable(feature = "char_escape_debug", since = "1.20.0")]
impl fmt::Display for EscapeDebug {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match &self.0 {
            EscapeDebugInner::Bytes(bytes) => f.write_str(bytes.as_str()),
            EscapeDebugInner::Char(chr) => f.write_char(*chr),
        }
    }
}
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Debug, Clone)]
pub struct ToLowercase(CaseMappingIter);
#[stable(feature = "rust1", since = "1.0.0")]
impl Iterator for ToLowercase {
    type Item = char;
    fn next(&mut self) -> Option<char> {
        self.0.next()
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.0.size_hint()
    }
}
#[stable(feature = "case_mapping_double_ended", since = "1.59.0")]
impl DoubleEndedIterator for ToLowercase {
    fn next_back(&mut self) -> Option<char> {
        self.0.next_back()
    }
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for ToLowercase {}
#[stable(feature = "exact_size_case_mapping_iter", since = "1.35.0")]
impl ExactSizeIterator for ToLowercase {}
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Debug, Clone)]
pub struct ToUppercase(CaseMappingIter);
#[stable(feature = "rust1", since = "1.0.0")]
impl Iterator for ToUppercase {
    type Item = char;
    fn next(&mut self) -> Option<char> {
        self.0.next()
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.0.size_hint()
    }
}
#[stable(feature = "case_mapping_double_ended", since = "1.59.0")]
impl DoubleEndedIterator for ToUppercase {
    fn next_back(&mut self) -> Option<char> {
        self.0.next_back()
    }
}
#[stable(feature = "fused", since = "1.26.0")]
impl FusedIterator for ToUppercase {}
#[stable(feature = "exact_size_case_mapping_iter", since = "1.35.0")]
impl ExactSizeIterator for ToUppercase {}
#[derive(Debug, Clone)]
enum CaseMappingIter {
    Three(char, char, char),
    Two(char, char),
    One(char),
    Zero,
}
impl CaseMappingIter {
    fn new(chars: [char; 3]) -> CaseMappingIter {
        if chars[2] == '\0' {
            if chars[1] == '\0' {
                CaseMappingIter::One(chars[0]) } else {
                CaseMappingIter::Two(chars[0], chars[1])
            }
        } else {
            CaseMappingIter::Three(chars[0], chars[1], chars[2])
        }
    }
}
impl Iterator for CaseMappingIter {
    type Item = char;
    fn next(&mut self) -> Option<char> {
        match *self {
            CaseMappingIter::Three(a, b, c) => {
                *self = CaseMappingIter::Two(b, c);
                Some(a)
            }
            CaseMappingIter::Two(b, c) => {
                *self = CaseMappingIter::One(c);
                Some(b)
            }
            CaseMappingIter::One(c) => {
                *self = CaseMappingIter::Zero;
                Some(c)
            }
            CaseMappingIter::Zero => None,
        }
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        let size = match self {
            CaseMappingIter::Three(..) => 3,
            CaseMappingIter::Two(..) => 2,
            CaseMappingIter::One(_) => 1,
            CaseMappingIter::Zero => 0,
        };
        (size, Some(size))
    }
}
impl DoubleEndedIterator for CaseMappingIter {
    fn next_back(&mut self) -> Option<char> {
        match *self {
            CaseMappingIter::Three(a, b, c) => {
                *self = CaseMappingIter::Two(a, b);
                Some(c)
            }
            CaseMappingIter::Two(b, c) => {
                *self = CaseMappingIter::One(b);
                Some(c)
            }
            CaseMappingIter::One(c) => {
                *self = CaseMappingIter::Zero;
                Some(c)
            }
            CaseMappingIter::Zero => None,
        }
    }
}
impl fmt::Display for CaseMappingIter {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match *self {
            CaseMappingIter::Three(a, b, c) => {
                f.write_char(a)?;
                f.write_char(b)?;
                f.write_char(c)
            }
            CaseMappingIter::Two(b, c) => {
                f.write_char(b)?;
                f.write_char(c)
            }
            CaseMappingIter::One(c) => f.write_char(c),
            CaseMappingIter::Zero => Ok(()),
        }
    }
}
#[stable(feature = "char_struct_display", since = "1.16.0")]
impl fmt::Display for ToLowercase {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Display::fmt(&self.0, f)
    }
}
#[stable(feature = "char_struct_display", since = "1.16.0")]
impl fmt::Display for ToUppercase {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Display::fmt(&self.0, f)
    }
}
#[stable(feature = "u8_from_char", since = "1.59.0")]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct TryFromCharError(pub(crate) ());
#[stable(feature = "u8_from_char", since = "1.59.0")]
impl fmt::Display for TryFromCharError {
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
        "unicode code point out of range".fmt(fmt)
    }
}
#[stable(feature = "u8_from_char", since = "1.59.0")]
impl Error for TryFromCharError {}