From 1b6a04ca5504955c571d1c97504fb45ea0befee4 Mon Sep 17 00:00:00 2001
From: Valentin Popov <valentin@popov.link>
Date: Mon, 8 Jan 2024 01:21:28 +0400
Subject: Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
---
vendor/encode_unicode/src/utf16_char.rs | 687 ++++++++++++++++++++++++++++++++
1 file changed, 687 insertions(+)
create mode 100644 vendor/encode_unicode/src/utf16_char.rs
(limited to 'vendor/encode_unicode/src/utf16_char.rs')
diff --git a/vendor/encode_unicode/src/utf16_char.rs b/vendor/encode_unicode/src/utf16_char.rs
new file mode 100644
index 0000000..d8a6cec
--- /dev/null
+++ b/vendor/encode_unicode/src/utf16_char.rs
@@ -0,0 +1,687 @@
+/* Copyright 2016 The encode_unicode Developers
+ *
+ * Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+ * http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+ * http://opensource.org/licenses/MIT>, at your option. This file may not be
+ * copied, modified, or distributed except according to those terms.
+ */
+
+use utf16_iterators::Utf16Iterator;
+use traits::{CharExt, U16UtfExt};
+use utf8_char::Utf8Char;
+use errors::{InvalidUtf16Slice, InvalidUtf16Array, InvalidUtf16Tuple};
+use errors::{NonBMPError, EmptyStrError, FromStrError};
+extern crate core;
+use self::core::{hash,fmt};
+use self::core::cmp::Ordering;
+use self::core::borrow::Borrow;
+use self::core::ops::Deref;
+use self::core::str::FromStr;
+#[cfg(feature="std")]
+use self::core::iter::FromIterator;
+#[cfg(feature="std")]
+#[allow(deprecated)]
+use std::ascii::AsciiExt;
+#[cfg(feature="ascii")]
+use self::core::char;
+#[cfg(feature="ascii")]
+extern crate ascii;
+#[cfg(feature="ascii")]
+use self::ascii::{AsciiChar,ToAsciiChar,ToAsciiCharError};
+
+
+// I don't think there is any good default value for char, but char does.
+#[derive(Default)]
+// char doesn't do anything more advanced than u32 for Eq/Ord, so we shouldn't either.
+// When it's a single unit, the second is zero, so Eq works.
+// #[derive(Ord)] however, breaks on surrogate pairs.
+#[derive(PartialEq,Eq)]
+#[derive(Clone,Copy)]
+
+
+/// An unicode codepoint stored as UTF-16.
+///
+/// It can be borrowed as an `u16` slice, and has the same size as `char`.
+pub struct Utf16Char {
+ units: [u16; 2],
+}
+
+
+ /////////////////////
+ //conversion traits//
+/////////////////////
+impl FromStr for Utf16Char {
+ type Err = FromStrError;
+ /// Create an `Utf16Char` from a string slice.
+ /// The string must contain exactly one codepoint.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use encode_unicode::error::FromStrError::*;
+ /// use encode_unicode::Utf16Char;
+ /// use std::str::FromStr;
+ ///
+ /// assert_eq!(Utf16Char::from_str("a"), Ok(Utf16Char::from('a')));
+ /// assert_eq!(Utf16Char::from_str("🂠"), Ok(Utf16Char::from('🂠')));
+ /// assert_eq!(Utf16Char::from_str(""), Err(Empty));
+ /// assert_eq!(Utf16Char::from_str("ab"), Err(MultipleCodepoints));
+ /// assert_eq!(Utf16Char::from_str("é"), Err(MultipleCodepoints));// 'e'+u301 combining mark
+ /// ```
+ fn from_str(s: &str) -> Result<Self, FromStrError> {
+ match Utf16Char::from_str_start(s) {
+ Ok((u16c,bytes)) if bytes == s.len() => Ok(u16c),
+ Ok((_,_)) => Err(FromStrError::MultipleCodepoints),
+ Err(EmptyStrError) => Err(FromStrError::Empty),
+ }
+ }
+}
+impl From<char> for Utf16Char {
+ fn from(c: char) -> Self {
+ let (first, second) = c.to_utf16_tuple();
+ Utf16Char{ units: [first, second.unwrap_or(0)] }
+ }
+}
+impl From<Utf8Char> for Utf16Char {
+ fn from(utf8: Utf8Char) -> Utf16Char {
+ let (b, utf8_len) = utf8.to_array();
+ match utf8_len {
+ 1 => Utf16Char{ units: [b[0] as u16, 0] },
+ 4 => {// need surrogate
+ let mut first = 0xd800 - (0x01_00_00u32 >> 10) as u16;
+ first += (b[0] as u16 & 0x07) << 8;
+ first += (b[1] as u16 & 0x3f) << 2;
+ first += (b[2] as u16 & 0x30) >> 4;
+ let mut second = 0xdc00;
+ second |= (b[2] as u16 & 0x0f) << 6;
+ second |= b[3] as u16 & 0x3f;
+ Utf16Char{ units: [first, second] }
+ },
+ _ => { // 2 or 3
+ let mut unit = ((b[0] as u16 & 0x1f) << 6) | (b[1] as u16 & 0x3f);
+ if utf8_len == 3 {
+ unit = (unit << 6) | (b[2] as u16 & 0x3f);
+ }
+ Utf16Char{ units: [unit, 0] }
+ },
+ }
+ }
+}
+impl From<Utf16Char> for char {
+ fn from(uc: Utf16Char) -> char {
+ char::from_utf16_array_unchecked(uc.to_array())
+ }
+}
+impl IntoIterator for Utf16Char {
+ type Item=u16;
+ type IntoIter=Utf16Iterator;
+ /// Iterate over the units.
+ fn into_iter(self) -> Utf16Iterator {
+ Utf16Iterator::from(self)
+ }
+}
+
+#[cfg(feature="std")]
+impl Extend<Utf16Char> for Vec<u16> {
+ fn extend<I:IntoIterator<Item=Utf16Char>>(&mut self, iter: I) {
+ let iter = iter.into_iter();
+ self.reserve(iter.size_hint().0);
+ for u16c in iter {
+ self.push(u16c.units[0]);
+ if u16c.units[1] != 0 {
+ self.push(u16c.units[1]);
+ }
+ }
+ }
+}
+#[cfg(feature="std")]
+impl<'a> Extend<&'a Utf16Char> for Vec<u16> {
+ fn extend<I:IntoIterator<Item=&'a Utf16Char>>(&mut self, iter: I) {
+ self.extend(iter.into_iter().cloned())
+ }
+}
+#[cfg(feature="std")]
+impl FromIterator<Utf16Char> for Vec<u16> {
+ fn from_iter<I:IntoIterator<Item=Utf16Char>>(iter: I) -> Self {
+ let mut vec = Vec::new();
+ vec.extend(iter);
+ return vec;
+ }
+}
+#[cfg(feature="std")]
+impl<'a> FromIterator<&'a Utf16Char> for Vec<u16> {
+ fn from_iter<I:IntoIterator<Item=&'a Utf16Char>>(iter: I) -> Self {
+ Self::from_iter(iter.into_iter().cloned())
+ }
+}
+
+#[cfg(feature="std")]
+impl Extend<Utf16Char> for String {
+ fn extend<I:IntoIterator<Item=Utf16Char>>(&mut self, iter: I) {
+ self.extend(iter.into_iter().map(|u16c| Utf8Char::from(u16c) ));
+ }
+}
+#[cfg(feature="std")]
+impl<'a> Extend<&'a Utf16Char> for String {
+ fn extend<I:IntoIterator<Item=&'a Utf16Char>>(&mut self, iter: I) {
+ self.extend(iter.into_iter().cloned());
+ }
+}
+#[cfg(feature="std")]
+impl FromIterator<Utf16Char> for String {
+ fn from_iter<I:IntoIterator<Item=Utf16Char>>(iter: I) -> Self {
+ let mut s = String::new();
+ s.extend(iter);
+ return s;
+ }
+}
+#[cfg(feature="std")]
+impl<'a> FromIterator<&'a Utf16Char> for String {
+ fn from_iter<I:IntoIterator<Item=&'a Utf16Char>>(iter: I) -> Self {
+ Self::from_iter(iter.into_iter().cloned())
+ }
+}
+
+
+ /////////////////
+ //getter traits//
+/////////////////
+impl AsRef<[u16]> for Utf16Char {
+ #[inline]
+ fn as_ref(&self) -> &[u16] {
+ &self.units[..self.len()]
+ }
+}
+impl Borrow<[u16]> for Utf16Char {
+ #[inline]
+ fn borrow(&self) -> &[u16] {
+ self.as_ref()
+ }
+}
+impl Deref for Utf16Char {
+ type Target = [u16];
+ #[inline]
+ fn deref(&self) -> &[u16] {
+ self.as_ref()
+ }
+}
+
+
+ ////////////////
+ //ascii traits//
+////////////////
+#[cfg(feature="std")]
+#[allow(deprecated)]
+impl AsciiExt for Utf16Char {
+ type Owned = Self;
+ fn is_ascii(&self) -> bool {
+ self.units[0] < 128
+ }
+ fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
+ self.to_ascii_lowercase() == other.to_ascii_lowercase()
+ }
+ fn to_ascii_uppercase(&self) -> Self {
+ let n = self.units[0].wrapping_sub(b'a' as u16);
+ if n < 26 {Utf16Char{ units: [n+b'A' as u16, 0] }}
+ else {*self}
+ }
+ fn to_ascii_lowercase(&self) -> Self {
+ let n = self.units[0].wrapping_sub(b'A' as u16);
+ if n < 26 {Utf16Char{ units: [n+b'a' as u16, 0] }}
+ else {*self}
+ }
+ fn make_ascii_uppercase(&mut self) {
+ *self = self.to_ascii_uppercase()
+ }
+ fn make_ascii_lowercase(&mut self) {
+ *self = self.to_ascii_lowercase();
+ }
+}
+
+#[cfg(feature="ascii")]
+/// Requires the feature "ascii".
+impl From<AsciiChar> for Utf16Char {
+ #[inline]
+ fn from(ac: AsciiChar) -> Self {
+ Utf16Char{ units: [ac.as_byte() as u16, 0] }
+ }
+}
+#[cfg(feature="ascii")]
+/// Requires the feature "ascii".
+impl ToAsciiChar for Utf16Char {
+ #[inline]
+ fn to_ascii_char(self) -> Result<AsciiChar, ToAsciiCharError> {
+ // ToAsciiCHar is not implemented for u16 in ascii 0.9.0
+ if self.is_ascii() {self.units[0] as u8} else {255}.to_ascii_char()
+ }
+ #[inline]
+ unsafe fn to_ascii_char_unchecked(self) -> AsciiChar {
+ (self.units[0] as u8).to_ascii_char_unchecked()
+ }
+}
+
+
+ /////////////////////////////////////////////////////////
+ //Genaral traits that cannot be derived to emulate char//
+/////////////////////////////////////////////////////////
+impl hash::Hash for Utf16Char {
+ fn hash<H : hash::Hasher>(&self, state: &mut H) {
+ self.to_char().hash(state);
+ }
+}
+impl fmt::Debug for Utf16Char {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ fmt::Debug::fmt(&self.to_char(), fmtr)
+ }
+}
+impl fmt::Display for Utf16Char {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ fmt::Display::fmt(&Utf8Char::from(*self), fmtr)
+ }
+}
+// Cannot derive these impls because two-unit characters must always compare
+// greater than one-unit ones.
+impl PartialOrd for Utf16Char {
+ #[inline]
+ fn partial_cmp(&self, rhs: &Self) -> Option<Ordering> {
+ Some(self.cmp(rhs))
+ }
+}
+impl Ord for Utf16Char {
+ #[inline]
+ fn cmp(&self, rhs: &Self) -> Ordering {
+ // Shift the first unit by 0xd if surrogate, and 0 otherwise.
+ // This ensures surrogates are always greater than 0xffff, and
+ // that the second unit only affect the result when the first are equal.
+ // Multiplying by a constant factor isn't enough because that factor
+ // would have to be greater than 1023 and smaller than 5.5.
+ // This transformation is less complicated than combine_surrogates().
+ let lhs = (self.units[0] as u32, self.units[1] as u32);
+ let rhs = (rhs.units[0] as u32, rhs.units[1] as u32);
+ let lhs = (lhs.0 << (lhs.1 >> 12)) + lhs.1;
+ let rhs = (rhs.0 << (rhs.1 >> 12)) + rhs.1;
+ lhs.cmp(&rhs)
+ }
+}
+
+
+ ////////////////////////////////
+ //Comparisons with other types//
+////////////////////////////////
+impl PartialEq<char> for Utf16Char {
+ fn eq(&self, u32c: &char) -> bool {
+ *self == Utf16Char::from(*u32c)
+ }
+}
+impl PartialEq<Utf16Char> for char {
+ fn eq(&self, u16c: &Utf16Char) -> bool {
+ Utf16Char::from(*self) == *u16c
+ }
+}
+impl PartialOrd<char> for Utf16Char {
+ fn partial_cmp(&self, u32c: &char) -> Option<Ordering> {
+ self.partial_cmp(&Utf16Char::from(*u32c))
+ }
+}
+impl PartialOrd<Utf16Char> for char {
+ fn partial_cmp(&self, u16c: &Utf16Char) -> Option<Ordering> {
+ Utf16Char::from(*self).partial_cmp(u16c)
+ }
+}
+
+impl PartialEq<Utf8Char> for Utf16Char {
+ fn eq(&self, u8c: &Utf8Char) -> bool {
+ *self == Utf16Char::from(*u8c)
+ }
+}
+impl PartialOrd<Utf8Char> for Utf16Char {
+ fn partial_cmp(&self, u8c: &Utf8Char) -> Option<Ordering> {
+ self.partial_cmp(&Utf16Char::from(*u8c))
+ }
+}
+// The other direction is implemented in utf8_char.rs
+
+/// Only considers the unit equal if the codepoint of the `Utf16Char` is not
+/// made up of a surrogate pair.
+///
+/// There is no impl in the opposite direction, as this should only be used to
+/// compare `Utf16Char`s against constants.
+///
+/// # Examples
+///
+/// ```
+/// # use encode_unicode::Utf16Char;
+/// assert!(Utf16Char::from('6') == b'6' as u16);
+/// assert!(Utf16Char::from('\u{FFFF}') == 0xffff_u16);
+/// assert!(Utf16Char::from_tuple((0xd876, Some(0xdef9))).unwrap() != 0xd876_u16);
+/// ```
+impl PartialEq<u16> for Utf16Char {
+ fn eq(&self, unit: &u16) -> bool {
+ self.units[0] == *unit && self.units[1] == 0
+ }
+}
+/// Only considers the byte equal if the codepoint of the `Utf16Char` is <= U+FF.
+///
+/// # Examples
+///
+/// ```
+/// # use encode_unicode::Utf16Char;
+/// assert!(Utf16Char::from('6') == b'6');
+/// assert!(Utf16Char::from('\u{00FF}') == b'\xff');
+/// assert!(Utf16Char::from('\u{0100}') != b'\0');
+/// ```
+impl PartialEq<u8> for Utf16Char {
+ fn eq(&self, byte: &u8) -> bool {
+ self.units[0] == *byte as u16
+ }
+}
+#[cfg(feature = "ascii")]
+/// `Utf16Char`s that are not ASCII never compare equal.
+impl PartialEq<AsciiChar> for Utf16Char {
+ #[inline]
+ fn eq(&self, ascii: &AsciiChar) -> bool {
+ self.units[0] == *ascii as u16
+ }
+}
+#[cfg(feature = "ascii")]
+/// `Utf16Char`s that are not ASCII never compare equal.
+impl PartialEq<Utf16Char> for AsciiChar {
+ #[inline]
+ fn eq(&self, u16c: &Utf16Char) -> bool {
+ *self as u16 == u16c.units[0]
+ }
+}
+#[cfg(feature = "ascii")]
+/// `Utf16Char`s that are not ASCII always compare greater.
+impl PartialOrd<AsciiChar> for Utf16Char {
+ #[inline]
+ fn partial_cmp(&self, ascii: &AsciiChar) -> Option<Ordering> {
+ self.units[0].partial_cmp(&(*ascii as u16))
+ }
+}
+#[cfg(feature = "ascii")]
+/// `Utf16Char`s that are not ASCII always compare greater.
+impl PartialOrd<Utf16Char> for AsciiChar {
+ #[inline]
+ fn partial_cmp(&self, u16c: &Utf16Char) -> Option<Ordering> {
+ (*self as u16).partial_cmp(&u16c.units[0])
+ }
+}
+
+
+ ///////////////////////////////////////////////////////
+ //pub impls that should be together for nicer rustdoc//
+///////////////////////////////////////////////////////
+impl Utf16Char {
+ /// Create an `Utf16Char` from the first codepoint in a string slice,
+ /// converting from UTF-8 to UTF-16.
+ ///
+ /// The returned `usize` is the number of UTF-8 bytes used from the str,
+ /// and not the number of UTF-16 units.
+ ///
+ /// Returns an error if the `str` is empty.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use encode_unicode::Utf16Char;
+ ///
+ /// assert_eq!(Utf16Char::from_str_start("a"), Ok((Utf16Char::from('a'),1)));
+ /// assert_eq!(Utf16Char::from_str_start("ab"), Ok((Utf16Char::from('a'),1)));
+ /// assert_eq!(Utf16Char::from_str_start("🂠 "), Ok((Utf16Char::from('🂠'),4)));
+ /// assert_eq!(Utf16Char::from_str_start("é"), Ok((Utf16Char::from('e'),1)));// 'e'+u301 combining mark
+ /// assert!(Utf16Char::from_str_start("").is_err());
+ /// ```
+ pub fn from_str_start(s: &str) -> Result<(Self,usize), EmptyStrError> {
+ if s.is_empty() {
+ return Err(EmptyStrError);
+ }
+ let b = s.as_bytes();
+ // Read the last byte first to reduce the number of unnecesary length checks.
+ match b[0] {
+ 0...127 => {// 1 byte => 1 unit
+ let unit = b[0] as u16;// 0b0000_0000_0xxx_xxxx
+ Ok((Utf16Char{ units: [unit, 0] }, 1))
+ },
+ 0b1000_0000...0b1101_1111 => {// 2 bytes => 1 unit
+ let unit = (((b[1] & 0x3f) as u16) << 0) // 0b0000_0000_00xx_xxxx
+ | (((b[0] & 0x1f) as u16) << 6);// 0b0000_0xxx_xx00_0000
+ Ok((Utf16Char{ units: [unit, 0] }, 2))
+ },
+ 0b1110_0000...0b1110_1111 => {// 3 bytes => 1 unit
+ let unit = (((b[2] & 0x3f) as u16) << 0) // 0b0000_0000_00xx_xxxx
+ | (((b[1] & 0x3f) as u16) << 6) // 0b0000_xxxx_xx00_0000
+ | (((b[0] & 0x0f) as u16) << 12);// 0bxxxx_0000_0000_0000
+ Ok((Utf16Char{ units: [unit, 0] }, 3))
+ },
+ _ => {// 4 bytes => 2 units
+ let second = 0xdc00 // 0b1101_1100_0000_0000
+ | (((b[3] & 0x3f) as u16) << 0) // 0b0000_0000_00xx_xxxx
+ | (((b[2] & 0x0f) as u16) << 6);// 0b0000_00xx_xx00_0000
+ let first = 0xd800-(0x01_00_00u32>>10) as u16// 0b1101_0111_1100_0000
+ + (((b[2] & 0x30) as u16) >> 4) // 0b0000_0000_0000_00xx
+ + (((b[1] & 0x3f) as u16) << 2) // 0b0000_0000_xxxx_xx00
+ + (((b[0] & 0x07) as u16) << 8); // 0b0000_0xxx_0000_0000
+ Ok((Utf16Char{ units: [first, second] }, 4))
+ }
+ }
+ }
+ /// Validate and store the first UTF-16 codepoint in the slice.
+ /// Also return how many units were needed.
+ pub fn from_slice_start(src: &[u16]) -> Result<(Self,usize), InvalidUtf16Slice> {
+ char::from_utf16_slice_start(src).map(|(_,len)| {
+ let second = if len==2 {src[1]} else {0};
+ (Utf16Char{ units: [src[0], second] }, len)
+ })
+ }
+ /// Store the first UTF-16 codepoint of the slice.
+ ///
+ /// # Safety
+ ///
+ /// The slice must be non-empty and start with a valid UTF-16 codepoint.
+ /// The length of the slice is never checked.
+ pub unsafe fn from_slice_start_unchecked(src: &[u16]) -> (Self,usize) {
+ let first = *src.get_unchecked(0);
+ if first.is_utf16_leading_surrogate() {
+ (Utf16Char{ units: [first, *src.get_unchecked(1)] }, 2)
+ } else {
+ (Utf16Char{ units: [first, 0] }, 1)
+ }
+ }
+ /// Validate and store an UTF-16 array as returned from `char.to_utf16_array()`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use encode_unicode::Utf16Char;
+ /// use encode_unicode::error::InvalidUtf16Array;
+ ///
+ /// assert_eq!(Utf16Char::from_array(['x' as u16, 'y' as u16]), Ok(Utf16Char::from('x')));
+ /// assert_eq!(Utf16Char::from_array(['睷' as u16, 0]), Ok(Utf16Char::from('睷')));
+ /// assert_eq!(Utf16Char::from_array([0xda6f, 0xdcde]), Ok(Utf16Char::from('\u{abcde}')));
+ /// assert_eq!(Utf16Char::from_array([0xf111, 0xdbad]), Ok(Utf16Char::from('\u{f111}')));
+ /// assert_eq!(Utf16Char::from_array([0xdaaf, 0xdaaf]), Err(InvalidUtf16Array::SecondIsNotTrailingSurrogate));
+ /// assert_eq!(Utf16Char::from_array([0xdcac, 0x9000]), Err(InvalidUtf16Array::FirstIsTrailingSurrogate));
+ /// ```
+ pub fn from_array(units: [u16; 2]) -> Result<Self,InvalidUtf16Array> {
+ if (units[0] & 0xf8_00) != 0xd8_00 {
+ Ok(Utf16Char { units: [units[0], 0] })
+ } else if units[0] < 0xdc_00 && (units[1] & 0xfc_00) == 0xdc_00 {
+ Ok(Utf16Char { units: units })
+ } else if units[0] < 0xdc_00 {
+ Err(InvalidUtf16Array::SecondIsNotTrailingSurrogate)
+ } else {
+ Err(InvalidUtf16Array::FirstIsTrailingSurrogate)
+ }
+ }
+ /// Create an `Utf16Char` from an array as returned from `char.to_utf16_array()`.
+ ///
+ /// # Safety
+ ///
+ /// The units must form a valid codepoint, and the second unit must be 0
+ /// when a surrogate pair is not required.
+ /// Violating this can easily lead to undefined behavior, although unlike
+ /// `char` bad `Utf16Char`s simply existing is not immediately UB.
+ pub unsafe fn from_array_unchecked(units: [u16; 2]) -> Self {
+ Utf16Char { units: units }
+ }
+ /// Validate and store a UTF-16 pair as returned from `char.to_utf16_tuple()`.
+ pub fn from_tuple(utf16: (u16,Option<u16>)) -> Result<Self,InvalidUtf16Tuple> {
+ unsafe {char::from_utf16_tuple(utf16).map(|_|
+ Self::from_tuple_unchecked(utf16)
+ )}
+ }
+ /// Create an `Utf16Char` from a tuple as returned from `char.to_utf16_tuple()`.
+ ///
+ /// # Safety
+ ///
+ /// The units must form a valid codepoint with the second being 0 when a
+ /// surrogate pair is not required.
+ /// Violating this can easily lead to undefined behavior.
+ pub unsafe fn from_tuple_unchecked(utf16: (u16,Option<u16>)) -> Self {
+ Utf16Char { units: [utf16.0, utf16.1.unwrap_or(0)] }
+ }
+ /// Create an `Utf16Char` from a single unit.
+ ///
+ /// Codepoints < '\u{1_0000}' (which fit in a `u16`) are part of the basic
+ /// multilingual plane unless they are reserved for surrogate pairs.
+ ///
+ /// # Errors
+ ///
+ /// Returns `NonBMPError` if the unit is in the range `0xd800..0xe000`
+ /// (which means that it's part of a surrogat pair)
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use encode_unicode::Utf16Char;
+ /// assert_eq!(Utf16Char::from_bmp(0x40).unwrap(), '@');
+ /// assert_eq!(Utf16Char::from_bmp('ø' as u16).unwrap(), 'ø');
+ /// assert!(Utf16Char::from_bmp(0xdddd).is_err());
+ /// ```
+ pub fn from_bmp(bmp_codepoint: u16) -> Result<Self,NonBMPError> {
+ if bmp_codepoint & 0xf800 != 0xd800 {
+ Ok(Utf16Char{ units: [bmp_codepoint, 0] })
+ } else {
+ Err(NonBMPError)
+ }
+ }
+ /// Create an `Utf16Char` from a single unit without checking that it's a
+ /// valid codepoint on its own.
+ ///
+ /// # Safety
+ ///
+ /// The unit must be less than 0xd800 or greater than 0xdfff.
+ /// In other words, not part of a surrogate pair.
+ /// Violating this can easily lead to undefined behavior.
+ #[inline]
+ pub unsafe fn from_bmp_unchecked(bmp_codepoint: u16) -> Self {
+ Utf16Char{ units: [bmp_codepoint, 0] }
+ }
+ /// Checks that the codepoint is in the basic multilingual plane.
+ ///
+ /// # Examples
+ /// ```
+ /// # use encode_unicode::Utf16Char;
+ /// assert_eq!(Utf16Char::from('e').is_bmp(), true);
+ /// assert_eq!(Utf16Char::from('€').is_bmp(), true);
+ /// assert_eq!(Utf16Char::from('𝔼').is_bmp(), false);
+ /// ```
+ #[inline]
+ pub fn is_bmp(&self) -> bool {
+ self.units[1] == 0
+ }
+
+ /// The number of units this character is made up of.
+ ///
+ /// Is either 1 or 2 and identical to `.as_char().len_utf16()`
+ /// or `.as_ref().len()`.
+ #[inline]
+ pub fn len(self) -> usize {
+ 1 + (self.units[1] as usize >> 15)
+ }
+ // There is no `.is_emty()` because it would always return false.
+
+ /// Checks that the codepoint is an ASCII character.
+ #[inline]
+ pub fn is_ascii(&self) -> bool {
+ self.units[0] <= 127
+ }
+ /// Checks that two characters are an ASCII case-insensitive match.
+ ///
+ /// Is equivalent to `a.to_ascii_lowercase() == b.to_ascii_lowercase()`.
+ #[cfg(feature="std")]
+ pub fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
+ self.to_ascii_lowercase() == other.to_ascii_lowercase()
+ }
+ /// Converts the character to its ASCII upper case equivalent.
+ ///
+ /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+ /// but non-ASCII letters are unchanged.
+ #[cfg(feature="std")]
+ pub fn to_ascii_uppercase(&self) -> Self {
+ let n = self.units[0].wrapping_sub(b'a' as u16);
+ if n < 26 {Utf16Char{ units: [n+b'A' as u16, 0] }}
+ else {*self}
+ }
+ /// Converts the character to its ASCII lower case equivalent.
+ ///
+ /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+ /// but non-ASCII letters are unchanged.
+ #[cfg(feature="std")]
+ pub fn to_ascii_lowercase(&self) -> Self {
+ let n = self.units[0].wrapping_sub(b'A' as u16);
+ if n < 26 {Utf16Char{ units: [n+b'a' as u16, 0] }}
+ else {*self}
+ }
+ /// Converts the character to its ASCII upper case equivalent in-place.
+ ///
+ /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+ /// but non-ASCII letters are unchanged.
+ #[cfg(feature="std")]
+ pub fn make_ascii_uppercase(&mut self) {
+ *self = self.to_ascii_uppercase()
+ }
+ /// Converts the character to its ASCII lower case equivalent in-place.
+ ///
+ /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+ /// but non-ASCII letters are unchanged.
+ #[cfg(feature="std")]
+ pub fn make_ascii_lowercase(&mut self) {
+ *self = self.to_ascii_lowercase();
+ }
+
+ /// Convert from UTF-16 to UTF-32
+ pub fn to_char(self) -> char {
+ self.into()
+ }
+ /// Write the internal representation to a slice,
+ /// and then returns the number of `u16`s written.
+ ///
+ /// # Panics
+ /// Will panic the buffer is too small;
+ /// You can get the required length from `.len()`,
+ /// but a buffer of length two is always large enough.
+ pub fn to_slice(self, dst: &mut[u16]) -> usize {
+ // Write the last unit first to avoid repeated length checks.
+ let extra = self.units[1] as usize >> 15;
+ match dst.get_mut(extra) {
+ Some(first) => *first = self.units[extra],
+ None => panic!("The provided buffer is too small.")
+ }
+ if extra != 0 {dst[0] = self.units[0];}
+ extra+1
+ }
+ /// Get the character represented as an array of two units.
+ ///
+ /// The second `u16` is zero for codepoints that fit in one unit.
+ #[inline]
+ pub fn to_array(self) -> [u16;2] {
+ self.units
+ }
+ /// The second `u16` is used for surrogate pairs.
+ #[inline]
+ pub fn to_tuple(self) -> (u16,Option<u16>) {
+ (self.units[0], if self.units[1]==0 {None} else {Some(self.units[1])})
+ }
+}
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