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-rw-r--r--library/std/src/sys_common/wtf8.rs926
-rw-r--r--library/std/src/sys_common/wtf8/tests.rs409
2 files changed, 1335 insertions, 0 deletions
diff --git a/library/std/src/sys_common/wtf8.rs b/library/std/src/sys_common/wtf8.rs
new file mode 100644
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+++ b/library/std/src/sys_common/wtf8.rs
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+//! Implementation of [the WTF-8 encoding](https://simonsapin.github.io/wtf-8/).
+//!
+//! This library uses Rust’s type system to maintain
+//! [well-formedness](https://simonsapin.github.io/wtf-8/#well-formed),
+//! like the `String` and `&str` types do for UTF-8.
+//!
+//! Since [WTF-8 must not be used
+//! for interchange](https://simonsapin.github.io/wtf-8/#intended-audience),
+//! this library deliberately does not provide access to the underlying bytes
+//! of WTF-8 strings,
+//! nor can it decode WTF-8 from arbitrary bytes.
+//! WTF-8 strings can be obtained from UTF-8, UTF-16, or code points.
+
+// this module is imported from @SimonSapin's repo and has tons of dead code on
+// unix (it's mostly used on windows), so don't worry about dead code here.
+#![allow(dead_code)]
+
+#[cfg(test)]
+mod tests;
+
+use core::str::next_code_point;
+
+use crate::borrow::Cow;
+use crate::char;
+use crate::collections::TryReserveError;
+use crate::fmt;
+use crate::hash::{Hash, Hasher};
+use crate::iter::FusedIterator;
+use crate::mem;
+use crate::ops;
+use crate::rc::Rc;
+use crate::slice;
+use crate::str;
+use crate::sync::Arc;
+use crate::sys_common::AsInner;
+
+const UTF8_REPLACEMENT_CHARACTER: &str = "\u{FFFD}";
+
+/// A Unicode code point: from U+0000 to U+10FFFF.
+///
+/// Compares with the `char` type,
+/// which represents a Unicode scalar value:
+/// a code point that is not a surrogate (U+D800 to U+DFFF).
+#[derive(Eq, PartialEq, Ord, PartialOrd, Clone, Copy)]
+pub struct CodePoint {
+ value: u32,
+}
+
+/// Format the code point as `U+` followed by four to six hexadecimal digits.
+/// Example: `U+1F4A9`
+impl fmt::Debug for CodePoint {
+ #[inline]
+ fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(formatter, "U+{:04X}", self.value)
+ }
+}
+
+impl CodePoint {
+ /// Unsafely creates a new `CodePoint` without checking the value.
+ ///
+ /// Only use when `value` is known to be less than or equal to 0x10FFFF.
+ #[inline]
+ pub unsafe fn from_u32_unchecked(value: u32) -> CodePoint {
+ CodePoint { value }
+ }
+
+ /// Creates a new `CodePoint` if the value is a valid code point.
+ ///
+ /// Returns `None` if `value` is above 0x10FFFF.
+ #[inline]
+ pub fn from_u32(value: u32) -> Option<CodePoint> {
+ match value {
+ 0..=0x10FFFF => Some(CodePoint { value }),
+ _ => None,
+ }
+ }
+
+ /// Creates a new `CodePoint` from a `char`.
+ ///
+ /// Since all Unicode scalar values are code points, this always succeeds.
+ #[inline]
+ pub fn from_char(value: char) -> CodePoint {
+ CodePoint { value: value as u32 }
+ }
+
+ /// Returns the numeric value of the code point.
+ #[inline]
+ pub fn to_u32(&self) -> u32 {
+ self.value
+ }
+
+ /// Optionally returns a Unicode scalar value for the code point.
+ ///
+ /// Returns `None` if the code point is a surrogate (from U+D800 to U+DFFF).
+ #[inline]
+ pub fn to_char(&self) -> Option<char> {
+ match self.value {
+ 0xD800..=0xDFFF => None,
+ _ => Some(unsafe { char::from_u32_unchecked(self.value) }),
+ }
+ }
+
+ /// Returns a Unicode scalar value for the code point.
+ ///
+ /// Returns `'\u{FFFD}'` (the replacement character “�”)
+ /// if the code point is a surrogate (from U+D800 to U+DFFF).
+ #[inline]
+ pub fn to_char_lossy(&self) -> char {
+ self.to_char().unwrap_or('\u{FFFD}')
+ }
+}
+
+/// An owned, growable string of well-formed WTF-8 data.
+///
+/// Similar to `String`, but can additionally contain surrogate code points
+/// if they’re not in a surrogate pair.
+#[derive(Eq, PartialEq, Ord, PartialOrd, Clone)]
+pub struct Wtf8Buf {
+ bytes: Vec<u8>,
+}
+
+impl ops::Deref for Wtf8Buf {
+ type Target = Wtf8;
+
+ fn deref(&self) -> &Wtf8 {
+ self.as_slice()
+ }
+}
+
+impl ops::DerefMut for Wtf8Buf {
+ fn deref_mut(&mut self) -> &mut Wtf8 {
+ self.as_mut_slice()
+ }
+}
+
+/// Format the string with double quotes,
+/// and surrogates as `\u` followed by four hexadecimal digits.
+/// Example: `"a\u{D800}"` for a string with code points [U+0061, U+D800]
+impl fmt::Debug for Wtf8Buf {
+ #[inline]
+ fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, formatter)
+ }
+}
+
+impl Wtf8Buf {
+ /// Creates a new, empty WTF-8 string.
+ #[inline]
+ pub fn new() -> Wtf8Buf {
+ Wtf8Buf { bytes: Vec::new() }
+ }
+
+ /// Creates a new, empty WTF-8 string with pre-allocated capacity for `capacity` bytes.
+ #[inline]
+ pub fn with_capacity(capacity: usize) -> Wtf8Buf {
+ Wtf8Buf { bytes: Vec::with_capacity(capacity) }
+ }
+
+ /// Creates a WTF-8 string from a UTF-8 `String`.
+ ///
+ /// This takes ownership of the `String` and does not copy.
+ ///
+ /// Since WTF-8 is a superset of UTF-8, this always succeeds.
+ #[inline]
+ pub fn from_string(string: String) -> Wtf8Buf {
+ Wtf8Buf { bytes: string.into_bytes() }
+ }
+
+ /// Creates a WTF-8 string from a UTF-8 `&str` slice.
+ ///
+ /// This copies the content of the slice.
+ ///
+ /// Since WTF-8 is a superset of UTF-8, this always succeeds.
+ #[inline]
+ pub fn from_str(str: &str) -> Wtf8Buf {
+ Wtf8Buf { bytes: <[_]>::to_vec(str.as_bytes()) }
+ }
+
+ pub fn clear(&mut self) {
+ self.bytes.clear()
+ }
+
+ /// Creates a WTF-8 string from a potentially ill-formed UTF-16 slice of 16-bit code units.
+ ///
+ /// This is lossless: calling `.encode_wide()` on the resulting string
+ /// will always return the original code units.
+ pub fn from_wide(v: &[u16]) -> Wtf8Buf {
+ let mut string = Wtf8Buf::with_capacity(v.len());
+ for item in char::decode_utf16(v.iter().cloned()) {
+ match item {
+ Ok(ch) => string.push_char(ch),
+ Err(surrogate) => {
+ let surrogate = surrogate.unpaired_surrogate();
+ // Surrogates are known to be in the code point range.
+ let code_point = unsafe { CodePoint::from_u32_unchecked(surrogate as u32) };
+ // Skip the WTF-8 concatenation check,
+ // surrogate pairs are already decoded by decode_utf16
+ string.push_code_point_unchecked(code_point)
+ }
+ }
+ }
+ string
+ }
+
+ /// Copied from String::push
+ /// This does **not** include the WTF-8 concatenation check.
+ fn push_code_point_unchecked(&mut self, code_point: CodePoint) {
+ let mut bytes = [0; 4];
+ let bytes = char::encode_utf8_raw(code_point.value, &mut bytes);
+ self.bytes.extend_from_slice(bytes)
+ }
+
+ #[inline]
+ pub fn as_slice(&self) -> &Wtf8 {
+ unsafe { Wtf8::from_bytes_unchecked(&self.bytes) }
+ }
+
+ #[inline]
+ pub fn as_mut_slice(&mut self) -> &mut Wtf8 {
+ unsafe { Wtf8::from_mut_bytes_unchecked(&mut self.bytes) }
+ }
+
+ /// Reserves capacity for at least `additional` more bytes to be inserted
+ /// in the given `Wtf8Buf`.
+ /// The collection may reserve more space to avoid frequent reallocations.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the new capacity overflows `usize`.
+ #[inline]
+ pub fn reserve(&mut self, additional: usize) {
+ self.bytes.reserve(additional)
+ }
+
+ /// Tries to reserve capacity for at least `additional` more length units
+ /// in the given `Wtf8Buf`. The `Wtf8Buf` may reserve more space to avoid
+ /// frequent reallocations. After calling `try_reserve`, capacity will be
+ /// greater than or equal to `self.len() + additional`. Does nothing if
+ /// capacity is already sufficient.
+ ///
+ /// # Errors
+ ///
+ /// If the capacity overflows, or the allocator reports a failure, then an error
+ /// is returned.
+ #[inline]
+ pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
+ self.bytes.try_reserve(additional)
+ }
+
+ #[inline]
+ pub fn reserve_exact(&mut self, additional: usize) {
+ self.bytes.reserve_exact(additional)
+ }
+
+ /// Tries to reserve the minimum capacity for exactly `additional`
+ /// length units in the given `Wtf8Buf`. After calling
+ /// `try_reserve_exact`, capacity will be greater than or equal to
+ /// `self.len() + additional` if it returns `Ok(())`.
+ /// Does nothing if the capacity is already sufficient.
+ ///
+ /// Note that the allocator may give the `Wtf8Buf` more space than it
+ /// requests. Therefore, capacity can not be relied upon to be precisely
+ /// minimal. Prefer [`try_reserve`] if future insertions are expected.
+ ///
+ /// [`try_reserve`]: Wtf8Buf::try_reserve
+ ///
+ /// # Errors
+ ///
+ /// If the capacity overflows, or the allocator reports a failure, then an error
+ /// is returned.
+ #[inline]
+ pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError> {
+ self.bytes.try_reserve_exact(additional)
+ }
+
+ #[inline]
+ pub fn shrink_to_fit(&mut self) {
+ self.bytes.shrink_to_fit()
+ }
+
+ #[inline]
+ pub fn shrink_to(&mut self, min_capacity: usize) {
+ self.bytes.shrink_to(min_capacity)
+ }
+
+ /// Returns the number of bytes that this string buffer can hold without reallocating.
+ #[inline]
+ pub fn capacity(&self) -> usize {
+ self.bytes.capacity()
+ }
+
+ /// Append a UTF-8 slice at the end of the string.
+ #[inline]
+ pub fn push_str(&mut self, other: &str) {
+ self.bytes.extend_from_slice(other.as_bytes())
+ }
+
+ /// Append a WTF-8 slice at the end of the string.
+ ///
+ /// This replaces newly paired surrogates at the boundary
+ /// with a supplementary code point,
+ /// like concatenating ill-formed UTF-16 strings effectively would.
+ #[inline]
+ pub fn push_wtf8(&mut self, other: &Wtf8) {
+ match ((&*self).final_lead_surrogate(), other.initial_trail_surrogate()) {
+ // Replace newly paired surrogates by a supplementary code point.
+ (Some(lead), Some(trail)) => {
+ let len_without_lead_surrogate = self.len() - 3;
+ self.bytes.truncate(len_without_lead_surrogate);
+ let other_without_trail_surrogate = &other.bytes[3..];
+ // 4 bytes for the supplementary code point
+ self.bytes.reserve(4 + other_without_trail_surrogate.len());
+ self.push_char(decode_surrogate_pair(lead, trail));
+ self.bytes.extend_from_slice(other_without_trail_surrogate);
+ }
+ _ => self.bytes.extend_from_slice(&other.bytes),
+ }
+ }
+
+ /// Append a Unicode scalar value at the end of the string.
+ #[inline]
+ pub fn push_char(&mut self, c: char) {
+ self.push_code_point_unchecked(CodePoint::from_char(c))
+ }
+
+ /// Append a code point at the end of the string.
+ ///
+ /// This replaces newly paired surrogates at the boundary
+ /// with a supplementary code point,
+ /// like concatenating ill-formed UTF-16 strings effectively would.
+ #[inline]
+ pub fn push(&mut self, code_point: CodePoint) {
+ if let trail @ 0xDC00..=0xDFFF = code_point.to_u32() {
+ if let Some(lead) = (&*self).final_lead_surrogate() {
+ let len_without_lead_surrogate = self.len() - 3;
+ self.bytes.truncate(len_without_lead_surrogate);
+ self.push_char(decode_surrogate_pair(lead, trail as u16));
+ return;
+ }
+ }
+
+ // No newly paired surrogates at the boundary.
+ self.push_code_point_unchecked(code_point)
+ }
+
+ /// Shortens a string to the specified length.
+ ///
+ /// # Panics
+ ///
+ /// Panics if `new_len` > current length,
+ /// or if `new_len` is not a code point boundary.
+ #[inline]
+ pub fn truncate(&mut self, new_len: usize) {
+ assert!(is_code_point_boundary(self, new_len));
+ self.bytes.truncate(new_len)
+ }
+
+ /// Consumes the WTF-8 string and tries to convert it to UTF-8.
+ ///
+ /// This does not copy the data.
+ ///
+ /// If the contents are not well-formed UTF-8
+ /// (that is, if the string contains surrogates),
+ /// the original WTF-8 string is returned instead.
+ pub fn into_string(self) -> Result<String, Wtf8Buf> {
+ match self.next_surrogate(0) {
+ None => Ok(unsafe { String::from_utf8_unchecked(self.bytes) }),
+ Some(_) => Err(self),
+ }
+ }
+
+ /// Consumes the WTF-8 string and converts it lossily to UTF-8.
+ ///
+ /// This does not copy the data (but may overwrite parts of it in place).
+ ///
+ /// Surrogates are replaced with `"\u{FFFD}"` (the replacement character “�”)
+ pub fn into_string_lossy(mut self) -> String {
+ let mut pos = 0;
+ loop {
+ match self.next_surrogate(pos) {
+ Some((surrogate_pos, _)) => {
+ pos = surrogate_pos + 3;
+ self.bytes[surrogate_pos..pos]
+ .copy_from_slice(UTF8_REPLACEMENT_CHARACTER.as_bytes());
+ }
+ None => return unsafe { String::from_utf8_unchecked(self.bytes) },
+ }
+ }
+ }
+
+ /// Converts this `Wtf8Buf` into a boxed `Wtf8`.
+ #[inline]
+ pub fn into_box(self) -> Box<Wtf8> {
+ unsafe { mem::transmute(self.bytes.into_boxed_slice()) }
+ }
+
+ /// Converts a `Box<Wtf8>` into a `Wtf8Buf`.
+ pub fn from_box(boxed: Box<Wtf8>) -> Wtf8Buf {
+ let bytes: Box<[u8]> = unsafe { mem::transmute(boxed) };
+ Wtf8Buf { bytes: bytes.into_vec() }
+ }
+}
+
+/// Creates a new WTF-8 string from an iterator of code points.
+///
+/// This replaces surrogate code point pairs with supplementary code points,
+/// like concatenating ill-formed UTF-16 strings effectively would.
+impl FromIterator<CodePoint> for Wtf8Buf {
+ fn from_iter<T: IntoIterator<Item = CodePoint>>(iter: T) -> Wtf8Buf {
+ let mut string = Wtf8Buf::new();
+ string.extend(iter);
+ string
+ }
+}
+
+/// Append code points from an iterator to the string.
+///
+/// This replaces surrogate code point pairs with supplementary code points,
+/// like concatenating ill-formed UTF-16 strings effectively would.
+impl Extend<CodePoint> for Wtf8Buf {
+ fn extend<T: IntoIterator<Item = CodePoint>>(&mut self, iter: T) {
+ let iterator = iter.into_iter();
+ let (low, _high) = iterator.size_hint();
+ // Lower bound of one byte per code point (ASCII only)
+ self.bytes.reserve(low);
+ iterator.for_each(move |code_point| self.push(code_point));
+ }
+
+ #[inline]
+ fn extend_one(&mut self, code_point: CodePoint) {
+ self.push(code_point);
+ }
+
+ #[inline]
+ fn extend_reserve(&mut self, additional: usize) {
+ // Lower bound of one byte per code point (ASCII only)
+ self.bytes.reserve(additional);
+ }
+}
+
+/// A borrowed slice of well-formed WTF-8 data.
+///
+/// Similar to `&str`, but can additionally contain surrogate code points
+/// if they’re not in a surrogate pair.
+#[derive(Eq, Ord, PartialEq, PartialOrd)]
+pub struct Wtf8 {
+ bytes: [u8],
+}
+
+impl AsInner<[u8]> for Wtf8 {
+ fn as_inner(&self) -> &[u8] {
+ &self.bytes
+ }
+}
+
+/// Format the slice with double quotes,
+/// and surrogates as `\u` followed by four hexadecimal digits.
+/// Example: `"a\u{D800}"` for a slice with code points [U+0061, U+D800]
+impl fmt::Debug for Wtf8 {
+ fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fn write_str_escaped(f: &mut fmt::Formatter<'_>, s: &str) -> fmt::Result {
+ use crate::fmt::Write;
+ for c in s.chars().flat_map(|c| c.escape_debug()) {
+ f.write_char(c)?
+ }
+ Ok(())
+ }
+
+ formatter.write_str("\"")?;
+ let mut pos = 0;
+ while let Some((surrogate_pos, surrogate)) = self.next_surrogate(pos) {
+ write_str_escaped(formatter, unsafe {
+ str::from_utf8_unchecked(&self.bytes[pos..surrogate_pos])
+ })?;
+ write!(formatter, "\\u{{{:x}}}", surrogate)?;
+ pos = surrogate_pos + 3;
+ }
+ write_str_escaped(formatter, unsafe { str::from_utf8_unchecked(&self.bytes[pos..]) })?;
+ formatter.write_str("\"")
+ }
+}
+
+impl fmt::Display for Wtf8 {
+ fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let wtf8_bytes = &self.bytes;
+ let mut pos = 0;
+ loop {
+ match self.next_surrogate(pos) {
+ Some((surrogate_pos, _)) => {
+ formatter.write_str(unsafe {
+ str::from_utf8_unchecked(&wtf8_bytes[pos..surrogate_pos])
+ })?;
+ formatter.write_str(UTF8_REPLACEMENT_CHARACTER)?;
+ pos = surrogate_pos + 3;
+ }
+ None => {
+ let s = unsafe { str::from_utf8_unchecked(&wtf8_bytes[pos..]) };
+ if pos == 0 { return s.fmt(formatter) } else { return formatter.write_str(s) }
+ }
+ }
+ }
+ }
+}
+
+impl Wtf8 {
+ /// Creates a WTF-8 slice from a UTF-8 `&str` slice.
+ ///
+ /// Since WTF-8 is a superset of UTF-8, this always succeeds.
+ #[inline]
+ pub fn from_str(value: &str) -> &Wtf8 {
+ unsafe { Wtf8::from_bytes_unchecked(value.as_bytes()) }
+ }
+
+ /// Creates a WTF-8 slice from a WTF-8 byte slice.
+ ///
+ /// Since the byte slice is not checked for valid WTF-8, this functions is
+ /// marked unsafe.
+ #[inline]
+ unsafe fn from_bytes_unchecked(value: &[u8]) -> &Wtf8 {
+ mem::transmute(value)
+ }
+
+ /// Creates a mutable WTF-8 slice from a mutable WTF-8 byte slice.
+ ///
+ /// Since the byte slice is not checked for valid WTF-8, this functions is
+ /// marked unsafe.
+ #[inline]
+ unsafe fn from_mut_bytes_unchecked(value: &mut [u8]) -> &mut Wtf8 {
+ mem::transmute(value)
+ }
+
+ /// Returns the length, in WTF-8 bytes.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.bytes.len()
+ }
+
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ self.bytes.is_empty()
+ }
+
+ /// Returns the code point at `position` if it is in the ASCII range,
+ /// or `b'\xFF' otherwise.
+ ///
+ /// # Panics
+ ///
+ /// Panics if `position` is beyond the end of the string.
+ #[inline]
+ pub fn ascii_byte_at(&self, position: usize) -> u8 {
+ match self.bytes[position] {
+ ascii_byte @ 0x00..=0x7F => ascii_byte,
+ _ => 0xFF,
+ }
+ }
+
+ /// Returns an iterator for the string’s code points.
+ #[inline]
+ pub fn code_points(&self) -> Wtf8CodePoints<'_> {
+ Wtf8CodePoints { bytes: self.bytes.iter() }
+ }
+
+ /// Tries to convert the string to UTF-8 and return a `&str` slice.
+ ///
+ /// Returns `None` if the string contains surrogates.
+ ///
+ /// This does not copy the data.
+ #[inline]
+ pub fn as_str(&self) -> Option<&str> {
+ // Well-formed WTF-8 is also well-formed UTF-8
+ // if and only if it contains no surrogate.
+ match self.next_surrogate(0) {
+ None => Some(unsafe { str::from_utf8_unchecked(&self.bytes) }),
+ Some(_) => None,
+ }
+ }
+
+ /// Lossily converts the string to UTF-8.
+ /// Returns a UTF-8 `&str` slice if the contents are well-formed in UTF-8.
+ ///
+ /// Surrogates are replaced with `"\u{FFFD}"` (the replacement character “�”).
+ ///
+ /// This only copies the data if necessary (if it contains any surrogate).
+ pub fn to_string_lossy(&self) -> Cow<'_, str> {
+ let surrogate_pos = match self.next_surrogate(0) {
+ None => return Cow::Borrowed(unsafe { str::from_utf8_unchecked(&self.bytes) }),
+ Some((pos, _)) => pos,
+ };
+ let wtf8_bytes = &self.bytes;
+ let mut utf8_bytes = Vec::with_capacity(self.len());
+ utf8_bytes.extend_from_slice(&wtf8_bytes[..surrogate_pos]);
+ utf8_bytes.extend_from_slice(UTF8_REPLACEMENT_CHARACTER.as_bytes());
+ let mut pos = surrogate_pos + 3;
+ loop {
+ match self.next_surrogate(pos) {
+ Some((surrogate_pos, _)) => {
+ utf8_bytes.extend_from_slice(&wtf8_bytes[pos..surrogate_pos]);
+ utf8_bytes.extend_from_slice(UTF8_REPLACEMENT_CHARACTER.as_bytes());
+ pos = surrogate_pos + 3;
+ }
+ None => {
+ utf8_bytes.extend_from_slice(&wtf8_bytes[pos..]);
+ return Cow::Owned(unsafe { String::from_utf8_unchecked(utf8_bytes) });
+ }
+ }
+ }
+ }
+
+ /// Converts the WTF-8 string to potentially ill-formed UTF-16
+ /// and return an iterator of 16-bit code units.
+ ///
+ /// This is lossless:
+ /// calling `Wtf8Buf::from_ill_formed_utf16` on the resulting code units
+ /// would always return the original WTF-8 string.
+ #[inline]
+ pub fn encode_wide(&self) -> EncodeWide<'_> {
+ EncodeWide { code_points: self.code_points(), extra: 0 }
+ }
+
+ #[inline]
+ fn next_surrogate(&self, mut pos: usize) -> Option<(usize, u16)> {
+ let mut iter = self.bytes[pos..].iter();
+ loop {
+ let b = *iter.next()?;
+ if b < 0x80 {
+ pos += 1;
+ } else if b < 0xE0 {
+ iter.next();
+ pos += 2;
+ } else if b == 0xED {
+ match (iter.next(), iter.next()) {
+ (Some(&b2), Some(&b3)) if b2 >= 0xA0 => {
+ return Some((pos, decode_surrogate(b2, b3)));
+ }
+ _ => pos += 3,
+ }
+ } else if b < 0xF0 {
+ iter.next();
+ iter.next();
+ pos += 3;
+ } else {
+ iter.next();
+ iter.next();
+ iter.next();
+ pos += 4;
+ }
+ }
+ }
+
+ #[inline]
+ fn final_lead_surrogate(&self) -> Option<u16> {
+ match self.bytes {
+ [.., 0xED, b2 @ 0xA0..=0xAF, b3] => Some(decode_surrogate(b2, b3)),
+ _ => None,
+ }
+ }
+
+ #[inline]
+ fn initial_trail_surrogate(&self) -> Option<u16> {
+ match self.bytes {
+ [0xED, b2 @ 0xB0..=0xBF, b3, ..] => Some(decode_surrogate(b2, b3)),
+ _ => None,
+ }
+ }
+
+ pub fn clone_into(&self, buf: &mut Wtf8Buf) {
+ self.bytes.clone_into(&mut buf.bytes)
+ }
+
+ /// Boxes this `Wtf8`.
+ #[inline]
+ pub fn into_box(&self) -> Box<Wtf8> {
+ let boxed: Box<[u8]> = self.bytes.into();
+ unsafe { mem::transmute(boxed) }
+ }
+
+ /// Creates a boxed, empty `Wtf8`.
+ pub fn empty_box() -> Box<Wtf8> {
+ let boxed: Box<[u8]> = Default::default();
+ unsafe { mem::transmute(boxed) }
+ }
+
+ #[inline]
+ pub fn into_arc(&self) -> Arc<Wtf8> {
+ let arc: Arc<[u8]> = Arc::from(&self.bytes);
+ unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Wtf8) }
+ }
+
+ #[inline]
+ pub fn into_rc(&self) -> Rc<Wtf8> {
+ let rc: Rc<[u8]> = Rc::from(&self.bytes);
+ unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Wtf8) }
+ }
+
+ #[inline]
+ pub fn make_ascii_lowercase(&mut self) {
+ self.bytes.make_ascii_lowercase()
+ }
+
+ #[inline]
+ pub fn make_ascii_uppercase(&mut self) {
+ self.bytes.make_ascii_uppercase()
+ }
+
+ #[inline]
+ pub fn to_ascii_lowercase(&self) -> Wtf8Buf {
+ Wtf8Buf { bytes: self.bytes.to_ascii_lowercase() }
+ }
+
+ #[inline]
+ pub fn to_ascii_uppercase(&self) -> Wtf8Buf {
+ Wtf8Buf { bytes: self.bytes.to_ascii_uppercase() }
+ }
+
+ #[inline]
+ pub fn is_ascii(&self) -> bool {
+ self.bytes.is_ascii()
+ }
+
+ #[inline]
+ pub fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
+ self.bytes.eq_ignore_ascii_case(&other.bytes)
+ }
+}
+
+/// Returns a slice of the given string for the byte range \[`begin`..`end`).
+///
+/// # Panics
+///
+/// Panics when `begin` and `end` do not point to code point boundaries,
+/// or point beyond the end of the string.
+impl ops::Index<ops::Range<usize>> for Wtf8 {
+ type Output = Wtf8;
+
+ #[inline]
+ fn index(&self, range: ops::Range<usize>) -> &Wtf8 {
+ // is_code_point_boundary checks that the index is in [0, .len()]
+ if range.start <= range.end
+ && is_code_point_boundary(self, range.start)
+ && is_code_point_boundary(self, range.end)
+ {
+ unsafe { slice_unchecked(self, range.start, range.end) }
+ } else {
+ slice_error_fail(self, range.start, range.end)
+ }
+ }
+}
+
+/// Returns a slice of the given string from byte `begin` to its end.
+///
+/// # Panics
+///
+/// Panics when `begin` is not at a code point boundary,
+/// or is beyond the end of the string.
+impl ops::Index<ops::RangeFrom<usize>> for Wtf8 {
+ type Output = Wtf8;
+
+ #[inline]
+ fn index(&self, range: ops::RangeFrom<usize>) -> &Wtf8 {
+ // is_code_point_boundary checks that the index is in [0, .len()]
+ if is_code_point_boundary(self, range.start) {
+ unsafe { slice_unchecked(self, range.start, self.len()) }
+ } else {
+ slice_error_fail(self, range.start, self.len())
+ }
+ }
+}
+
+/// Returns a slice of the given string from its beginning to byte `end`.
+///
+/// # Panics
+///
+/// Panics when `end` is not at a code point boundary,
+/// or is beyond the end of the string.
+impl ops::Index<ops::RangeTo<usize>> for Wtf8 {
+ type Output = Wtf8;
+
+ #[inline]
+ fn index(&self, range: ops::RangeTo<usize>) -> &Wtf8 {
+ // is_code_point_boundary checks that the index is in [0, .len()]
+ if is_code_point_boundary(self, range.end) {
+ unsafe { slice_unchecked(self, 0, range.end) }
+ } else {
+ slice_error_fail(self, 0, range.end)
+ }
+ }
+}
+
+impl ops::Index<ops::RangeFull> for Wtf8 {
+ type Output = Wtf8;
+
+ #[inline]
+ fn index(&self, _range: ops::RangeFull) -> &Wtf8 {
+ self
+ }
+}
+
+#[inline]
+fn decode_surrogate(second_byte: u8, third_byte: u8) -> u16 {
+ // The first byte is assumed to be 0xED
+ 0xD800 | (second_byte as u16 & 0x3F) << 6 | third_byte as u16 & 0x3F
+}
+
+#[inline]
+fn decode_surrogate_pair(lead: u16, trail: u16) -> char {
+ let code_point = 0x10000 + ((((lead - 0xD800) as u32) << 10) | (trail - 0xDC00) as u32);
+ unsafe { char::from_u32_unchecked(code_point) }
+}
+
+/// Copied from core::str::StrPrelude::is_char_boundary
+#[inline]
+pub fn is_code_point_boundary(slice: &Wtf8, index: usize) -> bool {
+ if index == slice.len() {
+ return true;
+ }
+ match slice.bytes.get(index) {
+ None => false,
+ Some(&b) => b < 128 || b >= 192,
+ }
+}
+
+/// Copied from core::str::raw::slice_unchecked
+#[inline]
+pub unsafe fn slice_unchecked(s: &Wtf8, begin: usize, end: usize) -> &Wtf8 {
+ // memory layout of a &[u8] and &Wtf8 are the same
+ Wtf8::from_bytes_unchecked(slice::from_raw_parts(s.bytes.as_ptr().add(begin), end - begin))
+}
+
+/// Copied from core::str::raw::slice_error_fail
+#[inline(never)]
+pub fn slice_error_fail(s: &Wtf8, begin: usize, end: usize) -> ! {
+ assert!(begin <= end);
+ panic!("index {begin} and/or {end} in `{s:?}` do not lie on character boundary");
+}
+
+/// Iterator for the code points of a WTF-8 string.
+///
+/// Created with the method `.code_points()`.
+#[derive(Clone)]
+pub struct Wtf8CodePoints<'a> {
+ bytes: slice::Iter<'a, u8>,
+}
+
+impl<'a> Iterator for Wtf8CodePoints<'a> {
+ type Item = CodePoint;
+
+ #[inline]
+ fn next(&mut self) -> Option<CodePoint> {
+ // SAFETY: `self.bytes` has been created from a WTF-8 string
+ unsafe { next_code_point(&mut self.bytes).map(|c| CodePoint { value: c }) }
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let len = self.bytes.len();
+ (len.saturating_add(3) / 4, Some(len))
+ }
+}
+
+/// Generates a wide character sequence for potentially ill-formed UTF-16.
+#[stable(feature = "rust1", since = "1.0.0")]
+#[derive(Clone)]
+pub struct EncodeWide<'a> {
+ code_points: Wtf8CodePoints<'a>,
+ extra: u16,
+}
+
+// Copied from libunicode/u_str.rs
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<'a> Iterator for EncodeWide<'a> {
+ type Item = u16;
+
+ #[inline]
+ fn next(&mut self) -> Option<u16> {
+ if self.extra != 0 {
+ let tmp = self.extra;
+ self.extra = 0;
+ return Some(tmp);
+ }
+
+ let mut buf = [0; 2];
+ self.code_points.next().map(|code_point| {
+ let n = char::encode_utf16_raw(code_point.value, &mut buf).len();
+ if n == 2 {
+ self.extra = buf[1];
+ }
+ buf[0]
+ })
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let (low, high) = self.code_points.size_hint();
+ let ext = (self.extra != 0) as usize;
+ // every code point gets either one u16 or two u16,
+ // so this iterator is between 1 or 2 times as
+ // long as the underlying iterator.
+ (low + ext, high.and_then(|n| n.checked_mul(2)).and_then(|n| n.checked_add(ext)))
+ }
+}
+
+#[stable(feature = "encode_wide_fused_iterator", since = "1.62.0")]
+impl FusedIterator for EncodeWide<'_> {}
+
+impl Hash for CodePoint {
+ #[inline]
+ fn hash<H: Hasher>(&self, state: &mut H) {
+ self.value.hash(state)
+ }
+}
+
+impl Hash for Wtf8Buf {
+ #[inline]
+ fn hash<H: Hasher>(&self, state: &mut H) {
+ state.write(&self.bytes);
+ 0xfeu8.hash(state)
+ }
+}
+
+impl Hash for Wtf8 {
+ #[inline]
+ fn hash<H: Hasher>(&self, state: &mut H) {
+ state.write(&self.bytes);
+ 0xfeu8.hash(state)
+ }
+}
diff --git a/library/std/src/sys_common/wtf8/tests.rs b/library/std/src/sys_common/wtf8/tests.rs
new file mode 100644
index 000000000..931996791
--- /dev/null
+++ b/library/std/src/sys_common/wtf8/tests.rs
@@ -0,0 +1,409 @@
+use super::*;
+use crate::borrow::Cow;
+
+#[test]
+fn code_point_from_u32() {
+ assert!(CodePoint::from_u32(0).is_some());
+ assert!(CodePoint::from_u32(0xD800).is_some());
+ assert!(CodePoint::from_u32(0x10FFFF).is_some());
+ assert!(CodePoint::from_u32(0x110000).is_none());
+}
+
+#[test]
+fn code_point_to_u32() {
+ fn c(value: u32) -> CodePoint {
+ CodePoint::from_u32(value).unwrap()
+ }
+ assert_eq!(c(0).to_u32(), 0);
+ assert_eq!(c(0xD800).to_u32(), 0xD800);
+ assert_eq!(c(0x10FFFF).to_u32(), 0x10FFFF);
+}
+
+#[test]
+fn code_point_from_char() {
+ assert_eq!(CodePoint::from_char('a').to_u32(), 0x61);
+ assert_eq!(CodePoint::from_char('💩').to_u32(), 0x1F4A9);
+}
+
+#[test]
+fn code_point_to_string() {
+ assert_eq!(format!("{:?}", CodePoint::from_char('a')), "U+0061");
+ assert_eq!(format!("{:?}", CodePoint::from_char('💩')), "U+1F4A9");
+}
+
+#[test]
+fn code_point_to_char() {
+ fn c(value: u32) -> CodePoint {
+ CodePoint::from_u32(value).unwrap()
+ }
+ assert_eq!(c(0x61).to_char(), Some('a'));
+ assert_eq!(c(0x1F4A9).to_char(), Some('💩'));
+ assert_eq!(c(0xD800).to_char(), None);
+}
+
+#[test]
+fn code_point_to_char_lossy() {
+ fn c(value: u32) -> CodePoint {
+ CodePoint::from_u32(value).unwrap()
+ }
+ assert_eq!(c(0x61).to_char_lossy(), 'a');
+ assert_eq!(c(0x1F4A9).to_char_lossy(), '💩');
+ assert_eq!(c(0xD800).to_char_lossy(), '\u{FFFD}');
+}
+
+#[test]
+fn wtf8buf_new() {
+ assert_eq!(Wtf8Buf::new().bytes, b"");
+}
+
+#[test]
+fn wtf8buf_from_str() {
+ assert_eq!(Wtf8Buf::from_str("").bytes, b"");
+ assert_eq!(Wtf8Buf::from_str("aé 💩").bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+fn wtf8buf_from_string() {
+ assert_eq!(Wtf8Buf::from_string(String::from("")).bytes, b"");
+ assert_eq!(Wtf8Buf::from_string(String::from("aé 💩")).bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+fn wtf8buf_from_wide() {
+ assert_eq!(Wtf8Buf::from_wide(&[]).bytes, b"");
+ assert_eq!(
+ Wtf8Buf::from_wide(&[0x61, 0xE9, 0x20, 0xD83D, 0xD83D, 0xDCA9]).bytes,
+ b"a\xC3\xA9 \xED\xA0\xBD\xF0\x9F\x92\xA9"
+ );
+}
+
+#[test]
+fn wtf8buf_push_str() {
+ let mut string = Wtf8Buf::new();
+ assert_eq!(string.bytes, b"");
+ string.push_str("aé 💩");
+ assert_eq!(string.bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+fn wtf8buf_push_char() {
+ let mut string = Wtf8Buf::from_str("aé ");
+ assert_eq!(string.bytes, b"a\xC3\xA9 ");
+ string.push_char('💩');
+ assert_eq!(string.bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+fn wtf8buf_push() {
+ let mut string = Wtf8Buf::from_str("aé ");
+ assert_eq!(string.bytes, b"a\xC3\xA9 ");
+ string.push(CodePoint::from_char('💩'));
+ assert_eq!(string.bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+
+ fn c(value: u32) -> CodePoint {
+ CodePoint::from_u32(value).unwrap()
+ }
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xD83D)); // lead
+ string.push(c(0xDCA9)); // trail
+ assert_eq!(string.bytes, b"\xF0\x9F\x92\xA9"); // Magic!
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xD83D)); // lead
+ string.push(c(0x20)); // not surrogate
+ string.push(c(0xDCA9)); // trail
+ assert_eq!(string.bytes, b"\xED\xA0\xBD \xED\xB2\xA9");
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xD800)); // lead
+ string.push(c(0xDBFF)); // lead
+ assert_eq!(string.bytes, b"\xED\xA0\x80\xED\xAF\xBF");
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xD800)); // lead
+ string.push(c(0xE000)); // not surrogate
+ assert_eq!(string.bytes, b"\xED\xA0\x80\xEE\x80\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xD7FF)); // not surrogate
+ string.push(c(0xDC00)); // trail
+ assert_eq!(string.bytes, b"\xED\x9F\xBF\xED\xB0\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0x61)); // not surrogate, < 3 bytes
+ string.push(c(0xDC00)); // trail
+ assert_eq!(string.bytes, b"\x61\xED\xB0\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push(c(0xDC00)); // trail
+ assert_eq!(string.bytes, b"\xED\xB0\x80");
+}
+
+#[test]
+fn wtf8buf_push_wtf8() {
+ let mut string = Wtf8Buf::from_str("aé");
+ assert_eq!(string.bytes, b"a\xC3\xA9");
+ string.push_wtf8(Wtf8::from_str(" 💩"));
+ assert_eq!(string.bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+
+ fn w(v: &[u8]) -> &Wtf8 {
+ unsafe { Wtf8::from_bytes_unchecked(v) }
+ }
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\xA0\xBD")); // lead
+ string.push_wtf8(w(b"\xED\xB2\xA9")); // trail
+ assert_eq!(string.bytes, b"\xF0\x9F\x92\xA9"); // Magic!
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\xA0\xBD")); // lead
+ string.push_wtf8(w(b" ")); // not surrogate
+ string.push_wtf8(w(b"\xED\xB2\xA9")); // trail
+ assert_eq!(string.bytes, b"\xED\xA0\xBD \xED\xB2\xA9");
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\xA0\x80")); // lead
+ string.push_wtf8(w(b"\xED\xAF\xBF")); // lead
+ assert_eq!(string.bytes, b"\xED\xA0\x80\xED\xAF\xBF");
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\xA0\x80")); // lead
+ string.push_wtf8(w(b"\xEE\x80\x80")); // not surrogate
+ assert_eq!(string.bytes, b"\xED\xA0\x80\xEE\x80\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\x9F\xBF")); // not surrogate
+ string.push_wtf8(w(b"\xED\xB0\x80")); // trail
+ assert_eq!(string.bytes, b"\xED\x9F\xBF\xED\xB0\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"a")); // not surrogate, < 3 bytes
+ string.push_wtf8(w(b"\xED\xB0\x80")); // trail
+ assert_eq!(string.bytes, b"\x61\xED\xB0\x80");
+
+ let mut string = Wtf8Buf::new();
+ string.push_wtf8(w(b"\xED\xB0\x80")); // trail
+ assert_eq!(string.bytes, b"\xED\xB0\x80");
+}
+
+#[test]
+fn wtf8buf_truncate() {
+ let mut string = Wtf8Buf::from_str("aé");
+ string.truncate(1);
+ assert_eq!(string.bytes, b"a");
+}
+
+#[test]
+#[should_panic]
+fn wtf8buf_truncate_fail_code_point_boundary() {
+ let mut string = Wtf8Buf::from_str("aé");
+ string.truncate(2);
+}
+
+#[test]
+#[should_panic]
+fn wtf8buf_truncate_fail_longer() {
+ let mut string = Wtf8Buf::from_str("aé");
+ string.truncate(4);
+}
+
+#[test]
+fn wtf8buf_into_string() {
+ let mut string = Wtf8Buf::from_str("aé 💩");
+ assert_eq!(string.clone().into_string(), Ok(String::from("aé 💩")));
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ assert_eq!(string.clone().into_string(), Err(string));
+}
+
+#[test]
+fn wtf8buf_into_string_lossy() {
+ let mut string = Wtf8Buf::from_str("aé 💩");
+ assert_eq!(string.clone().into_string_lossy(), String::from("aé 💩"));
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ assert_eq!(string.clone().into_string_lossy(), String::from("aé 💩�"));
+}
+
+#[test]
+fn wtf8buf_from_iterator() {
+ fn f(values: &[u32]) -> Wtf8Buf {
+ values.iter().map(|&c| CodePoint::from_u32(c).unwrap()).collect::<Wtf8Buf>()
+ }
+ assert_eq!(f(&[0x61, 0xE9, 0x20, 0x1F4A9]).bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+
+ assert_eq!(f(&[0xD83D, 0xDCA9]).bytes, b"\xF0\x9F\x92\xA9"); // Magic!
+ assert_eq!(f(&[0xD83D, 0x20, 0xDCA9]).bytes, b"\xED\xA0\xBD \xED\xB2\xA9");
+ assert_eq!(f(&[0xD800, 0xDBFF]).bytes, b"\xED\xA0\x80\xED\xAF\xBF");
+ assert_eq!(f(&[0xD800, 0xE000]).bytes, b"\xED\xA0\x80\xEE\x80\x80");
+ assert_eq!(f(&[0xD7FF, 0xDC00]).bytes, b"\xED\x9F\xBF\xED\xB0\x80");
+ assert_eq!(f(&[0x61, 0xDC00]).bytes, b"\x61\xED\xB0\x80");
+ assert_eq!(f(&[0xDC00]).bytes, b"\xED\xB0\x80");
+}
+
+#[test]
+fn wtf8buf_extend() {
+ fn e(initial: &[u32], extended: &[u32]) -> Wtf8Buf {
+ fn c(value: &u32) -> CodePoint {
+ CodePoint::from_u32(*value).unwrap()
+ }
+ let mut string = initial.iter().map(c).collect::<Wtf8Buf>();
+ string.extend(extended.iter().map(c));
+ string
+ }
+
+ assert_eq!(e(&[0x61, 0xE9], &[0x20, 0x1F4A9]).bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+
+ assert_eq!(e(&[0xD83D], &[0xDCA9]).bytes, b"\xF0\x9F\x92\xA9"); // Magic!
+ assert_eq!(e(&[0xD83D, 0x20], &[0xDCA9]).bytes, b"\xED\xA0\xBD \xED\xB2\xA9");
+ assert_eq!(e(&[0xD800], &[0xDBFF]).bytes, b"\xED\xA0\x80\xED\xAF\xBF");
+ assert_eq!(e(&[0xD800], &[0xE000]).bytes, b"\xED\xA0\x80\xEE\x80\x80");
+ assert_eq!(e(&[0xD7FF], &[0xDC00]).bytes, b"\xED\x9F\xBF\xED\xB0\x80");
+ assert_eq!(e(&[0x61], &[0xDC00]).bytes, b"\x61\xED\xB0\x80");
+ assert_eq!(e(&[], &[0xDC00]).bytes, b"\xED\xB0\x80");
+}
+
+#[test]
+fn wtf8buf_show() {
+ let mut string = Wtf8Buf::from_str("a\té \u{7f}💩\r");
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ assert_eq!(format!("{string:?}"), "\"a\\té \\u{7f}\u{1f4a9}\\r\\u{d800}\"");
+}
+
+#[test]
+fn wtf8buf_as_slice() {
+ assert_eq!(Wtf8Buf::from_str("aé").as_slice(), Wtf8::from_str("aé"));
+}
+
+#[test]
+fn wtf8buf_show_str() {
+ let text = "a\té 💩\r";
+ let string = Wtf8Buf::from_str(text);
+ assert_eq!(format!("{text:?}"), format!("{string:?}"));
+}
+
+#[test]
+fn wtf8_from_str() {
+ assert_eq!(&Wtf8::from_str("").bytes, b"");
+ assert_eq!(&Wtf8::from_str("aé 💩").bytes, b"a\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+fn wtf8_len() {
+ assert_eq!(Wtf8::from_str("").len(), 0);
+ assert_eq!(Wtf8::from_str("aé 💩").len(), 8);
+}
+
+#[test]
+fn wtf8_slice() {
+ assert_eq!(&Wtf8::from_str("aé 💩")[1..4].bytes, b"\xC3\xA9 ");
+}
+
+#[test]
+#[should_panic]
+fn wtf8_slice_not_code_point_boundary() {
+ let _ = &Wtf8::from_str("aé 💩")[2..4];
+}
+
+#[test]
+fn wtf8_slice_from() {
+ assert_eq!(&Wtf8::from_str("aé 💩")[1..].bytes, b"\xC3\xA9 \xF0\x9F\x92\xA9");
+}
+
+#[test]
+#[should_panic]
+fn wtf8_slice_from_not_code_point_boundary() {
+ let _ = &Wtf8::from_str("aé 💩")[2..];
+}
+
+#[test]
+fn wtf8_slice_to() {
+ assert_eq!(&Wtf8::from_str("aé 💩")[..4].bytes, b"a\xC3\xA9 ");
+}
+
+#[test]
+#[should_panic]
+fn wtf8_slice_to_not_code_point_boundary() {
+ let _ = &Wtf8::from_str("aé 💩")[5..];
+}
+
+#[test]
+fn wtf8_ascii_byte_at() {
+ let slice = Wtf8::from_str("aé 💩");
+ assert_eq!(slice.ascii_byte_at(0), b'a');
+ assert_eq!(slice.ascii_byte_at(1), b'\xFF');
+ assert_eq!(slice.ascii_byte_at(2), b'\xFF');
+ assert_eq!(slice.ascii_byte_at(3), b' ');
+ assert_eq!(slice.ascii_byte_at(4), b'\xFF');
+}
+
+#[test]
+fn wtf8_code_points() {
+ fn c(value: u32) -> CodePoint {
+ CodePoint::from_u32(value).unwrap()
+ }
+ fn cp(string: &Wtf8Buf) -> Vec<Option<char>> {
+ string.code_points().map(|c| c.to_char()).collect::<Vec<_>>()
+ }
+ let mut string = Wtf8Buf::from_str("é ");
+ assert_eq!(cp(&string), [Some('é'), Some(' ')]);
+ string.push(c(0xD83D));
+ assert_eq!(cp(&string), [Some('é'), Some(' '), None]);
+ string.push(c(0xDCA9));
+ assert_eq!(cp(&string), [Some('é'), Some(' '), Some('💩')]);
+}
+
+#[test]
+fn wtf8_as_str() {
+ assert_eq!(Wtf8::from_str("").as_str(), Some(""));
+ assert_eq!(Wtf8::from_str("aé 💩").as_str(), Some("aé 💩"));
+ let mut string = Wtf8Buf::new();
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ assert_eq!(string.as_str(), None);
+}
+
+#[test]
+fn wtf8_to_string_lossy() {
+ assert_eq!(Wtf8::from_str("").to_string_lossy(), Cow::Borrowed(""));
+ assert_eq!(Wtf8::from_str("aé 💩").to_string_lossy(), Cow::Borrowed("aé 💩"));
+ let mut string = Wtf8Buf::from_str("aé 💩");
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ let expected: Cow<'_, str> = Cow::Owned(String::from("aé 💩�"));
+ assert_eq!(string.to_string_lossy(), expected);
+}
+
+#[test]
+fn wtf8_display() {
+ fn d(b: &[u8]) -> String {
+ (&unsafe { Wtf8::from_bytes_unchecked(b) }).to_string()
+ }
+
+ assert_eq!("", d("".as_bytes()));
+ assert_eq!("aé 💩", d("aé 💩".as_bytes()));
+
+ let mut string = Wtf8Buf::from_str("aé 💩");
+ string.push(CodePoint::from_u32(0xD800).unwrap());
+ assert_eq!("aé 💩�", d(string.as_inner()));
+}
+
+#[test]
+fn wtf8_encode_wide() {
+ let mut string = Wtf8Buf::from_str("aé ");
+ string.push(CodePoint::from_u32(0xD83D).unwrap());
+ string.push_char('💩');
+ assert_eq!(
+ string.encode_wide().collect::<Vec<_>>(),
+ vec![0x61, 0xE9, 0x20, 0xD83D, 0xD83D, 0xDCA9]
+ );
+}
+
+#[test]
+fn wtf8_encode_wide_size_hint() {
+ let string = Wtf8Buf::from_str("\u{12345}");
+ let mut iter = string.encode_wide();
+ assert_eq!((1, Some(8)), iter.size_hint());
+ iter.next().unwrap();
+ assert_eq!((1, Some(1)), iter.size_hint());
+ iter.next().unwrap();
+ assert_eq!((0, Some(0)), iter.size_hint());
+ assert!(iter.next().is_none());
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-17 08:26:00 +0000