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/decoding_iterators.rs | 494 ++++++++++++++++++++++++
1 file changed, 494 insertions(+)
create mode 100644 vendor/encode_unicode/src/decoding_iterators.rs
(limited to 'vendor/encode_unicode/src/decoding_iterators.rs')
diff --git a/vendor/encode_unicode/src/decoding_iterators.rs b/vendor/encode_unicode/src/decoding_iterators.rs
new file mode 100644
index 0000000..4ef4125
--- /dev/null
+++ b/vendor/encode_unicode/src/decoding_iterators.rs
@@ -0,0 +1,494 @@
+/* Copyright 2018 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.
+ */
+
+//! Iterators that turn multiple `u8`s or `u16`s into `Utf*Char`s, but can fail.
+//!
+//! To be predictable, all errors consume one element each.
+//!
+//! The iterator adaptors produce neither offset nor element length to work
+//! well with other adaptors,
+//! while the slice iterators yield both to make more advanced use cases easy.
+
+use errors::{InvalidUtf8Slice, InvalidUtf16FirstUnit, Utf16PairError};
+use errors::InvalidUtf8Slice::*;
+use errors::InvalidUtf8::*;
+use errors::InvalidUtf8FirstByte::*;
+use errors::InvalidUtf16Slice::*;
+use errors::InvalidCodepoint::*;
+use errors::Utf16PairError::*;
+use utf8_char::Utf8Char;
+use utf16_char::Utf16Char;
+use traits::U16UtfExt;
+extern crate core;
+use self::core::borrow::Borrow;
+use self::core::fmt::{self, Debug};
+use self::core::iter::Chain;
+use self::core::option;
+
+
+/// Decodes UTF-8 characters from a byte iterator into `Utf8Char`s.
+///
+/// See [`IterExt::to_utf8chars()`](../trait.IterExt.html#tymethod.to_utf8chars)
+/// for examples and error handling.
+#[derive(Clone, Default)]
+pub struct Utf8CharMerger<B:Borrow<u8>, I:Iterator<Item=B>> {
+ iter: I,
+ /// number of bytes that were read before an error was detected
+ after_err_leftover: u8,
+ /// stack because it simplifies popping.
+ after_err_stack: [u8; 3],
+}
+impl<B:Borrow<u8>, I:Iterator<Item=B>, T:IntoIterator<IntoIter=I,Item=B>>
+From<T> for Utf8CharMerger<B, I> {
+ fn from(t: T) -> Self {
+ Utf8CharMerger {
+ iter: t.into_iter(),
+ after_err_leftover: 0,
+ after_err_stack: [0; 3],
+ }
+ }
+}
+impl<B:Borrow<u8>, I:Iterator<Item=B>> Utf8CharMerger<B,I> {
+ /// Extract the inner iterator.
+ ///
+ /// If the last item produced by `.next()` was an `Err`,
+ /// up to three following bytes might be missing.
+ /// The exact number of missing bytes for each error type should not be relied on.
+ ///
+ /// # Examples
+ ///
+ /// Three bytes swallowed:
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// let mut merger = b"\xf4\xa1\xb2FS".iter().to_utf8chars();
+ /// assert!(merger.next().unwrap().is_err());
+ /// let mut inner: std::slice::Iter<u8> = merger.into_inner();
+ /// assert_eq!(inner.next(), Some(&b'S')); // b'\xa1', b'\xb2' and b'F' disappeared
+ /// ```
+ ///
+ /// All bytes present:
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// let mut merger = b"\xb0FS".iter().to_utf8chars();
+ /// assert!(merger.next().unwrap().is_err());
+ /// assert_eq!(merger.into_inner().next(), Some(&b'F'));
+ /// ```
+ ///
+ /// Two bytes missing:
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// let mut merger = b"\xe0\x80\x80FS".iter().to_utf8chars();
+ /// assert!(merger.next().unwrap().is_err());
+ /// assert_eq!(merger.into_inner().next(), Some(&b'F'));
+ /// ```
+ pub fn into_inner(self) -> I {
+ self.iter
+ }
+
+ fn save(&mut self, bytes: &[u8;4], len: usize) {
+ // forget bytes[0] and push the others onto self.after_err_stack (in reverse).
+ for &after_err in bytes[1..len].iter().rev() {
+ self.after_err_stack[self.after_err_leftover as usize] = after_err;
+ self.after_err_leftover += 1;
+ }
+ }
+ /// Reads len-1 bytes into bytes[1..]
+ fn extra(&mut self, bytes: &mut[u8;4], len: usize) -> Result<(),InvalidUtf8Slice> {
+ // This is the only function that pushes onto after_err_stack,
+ // and it checks that all bytes are continuation bytes before fetching the next one.
+ // Therefore only the last byte retrieved can be a non-continuation byte.
+ // That last byte is also the last to be retrieved from after_err.
+ //
+ // Before this function is called, there has been retrieved at least one byte.
+ // If that byte was a continuation byte, next() produces an error
+ // and won't call this function.
+ // Therefore, we know that after_err is empty at this point.
+ // This means that we can use self.iter directly, and knows where to start pushing
+ debug_assert_eq!(self.after_err_leftover, 0, "first: {:#02x}, stack: {:?}", bytes[0], self.after_err_stack);
+ for i in 1..len {
+ if let Some(extra) = self.iter.next() {
+ let extra = *extra.borrow();
+ bytes[i] = extra;
+ if extra & 0b1100_0000 != 0b1000_0000 {
+ // not a continuation byte
+ self.save(bytes, i+1);
+ return Err(InvalidUtf8Slice::Utf8(NotAContinuationByte(i)))
+ }
+ } else {
+ self.save(bytes, i);
+ return Err(TooShort(len));
+ }
+ }
+ Ok(())
+ }
+}
+impl<B:Borrow<u8>, I:Iterator<Item=B>> Iterator for Utf8CharMerger<B,I> {
+ type Item = Result<Utf8Char,InvalidUtf8Slice>;
+ fn next(&mut self) -> Option<Self::Item> {
+ let first: u8;
+ if self.after_err_leftover != 0 {
+ self.after_err_leftover -= 1;
+ first = self.after_err_stack[self.after_err_leftover as usize];
+ } else if let Some(next) = self.iter.next() {
+ first = *next.borrow();
+ } else {
+ return None;
+ }
+
+ unsafe {
+ let mut bytes = [first, 0, 0, 0];
+ let ok = match first {
+ 0b0000_0000...0b0111_1111 => {/*1 and */Ok(())},
+ 0b1100_0010...0b1101_1111 => {//2 and not overlong
+ self.extra(&mut bytes, 2) // no extra validation required
+ },
+ 0b1110_0000...0b1110_1111 => {//3
+ if let Err(e) = self.extra(&mut bytes, 3) {
+ Err(e)
+ } else if bytes[0] == 0b1110_0000 && bytes[1] <= 0b10_011111 {
+ self.save(&bytes, 3);
+ Err(Utf8(OverLong))
+ } else if bytes[0] == 0b1110_1101 && bytes[1] & 0b11_100000 == 0b10_100000 {
+ self.save(&bytes, 3);
+ Err(Codepoint(Utf16Reserved))
+ } else {
+ Ok(())
+ }
+ },
+ 0b1111_0000...0b1111_0100 => {//4
+ if let Err(e) = self.extra(&mut bytes, 4) {
+ Err(e)
+ } else if bytes[0] == 0b11110_000 && bytes[1] <= 0b10_001111 {
+ self.save(&bytes, 4);
+ Err(InvalidUtf8Slice::Utf8(OverLong))
+ } else if bytes[0] == 0b11110_100 && bytes[1] > 0b10_001111 {
+ self.save(&bytes, 4);
+ Err(InvalidUtf8Slice::Codepoint(TooHigh))
+ } else {
+ Ok(())
+ }
+ },
+ 0b1000_0000...0b1011_1111 => {// continuation byte
+ Err(Utf8(FirstByte(ContinuationByte)))
+ },
+ 0b1100_0000...0b1100_0001 => {// 2 and overlong
+ Err(Utf8(OverLong))
+ },
+ 0b1111_0101...0b1111_0111 => {// 4 and too high codepoint
+ Err(Codepoint(TooHigh))
+ },
+ 0b1111_1000...0b1111_1111 => {
+ Err(Utf8(FirstByte(TooLongSeqence)))
+ },
+ _ => unreachable!("all possible byte values should be covered")
+ };
+ Some(ok.map(|()| Utf8Char::from_array_unchecked(bytes) ))
+ }
+ }
+ fn size_hint(&self) -> (usize,Option<usize>) {
+ let (iter_min, iter_max) = self.iter.size_hint();
+ // cannot be exact, so KISS
+ let min = iter_min / 4; // don't bother rounding up or accounting for after_err
+ // handle edge case of max > usize::MAX-3 just in case.
+ // Using wrapping_add() wouldn't violate any API contract as the trait isn't unsafe.
+ let max = iter_max.and_then(|max| {
+ max.checked_add(self.after_err_leftover as usize)
+ });
+ (min, max)
+ }
+}
+impl<B:Borrow<u8>, I:Iterator<Item=B>+Debug> Debug for Utf8CharMerger<B,I> {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ let mut in_order = [0u8; 3];
+ for i in 0..self.after_err_leftover as usize {
+ in_order[i] = self.after_err_stack[self.after_err_leftover as usize - i - 1];
+ }
+ fmtr.debug_struct("Utf8CharMerger")
+ .field("buffered", &&in_order[..self.after_err_leftover as usize])
+ .field("inner", &self.iter)
+ .finish()
+ }
+}
+
+
+/// An [`Utf8CharMerger`](struct.Utf8CharMerger.html) that also produces
+/// offsets and lengths, but can only iterate over slices.
+///
+/// See [`SliceExt::utf8char_indices()`](../trait.SliceExt.html#tymethod.utf8char_indices)
+/// for examples and error handling.
+#[derive(Clone, Default)]
+pub struct Utf8CharDecoder<'a> {
+ slice: &'a[u8],
+ index: usize,
+}
+impl<'a> From<&'a[u8]> for Utf8CharDecoder<'a> {
+ fn from(s: &[u8]) -> Utf8CharDecoder {
+ Utf8CharDecoder { slice: s, index: 0 }
+ }
+}
+impl<'a> Utf8CharDecoder<'a> {
+ /// Extract the remainder of the source slice.
+ ///
+ /// # Examples
+ ///
+ /// Unlike `Utf8CharMerger::into_inner()`, bytes directly after an error
+ /// are never swallowed:
+ /// ```
+ /// # use encode_unicode::SliceExt;
+ /// let mut iter = b"\xf4\xa1\xb2FS".utf8char_indices();
+ /// assert!(iter.next().unwrap().1.is_err());
+ /// assert_eq!(iter.as_slice(), b"\xa1\xb2FS");
+ /// ```
+ pub fn as_slice(&self) -> &'a[u8] {
+ &self.slice[self.index..]
+ }
+}
+impl<'a> Iterator for Utf8CharDecoder<'a> {
+ type Item = (usize, Result<Utf8Char,InvalidUtf8Slice>, usize);
+ fn next(&mut self) -> Option<Self::Item> {
+ let start = self.index;
+ match Utf8Char::from_slice_start(&self.slice[self.index..]) {
+ Ok((u8c, len)) => {
+ self.index += len;
+ Some((start, Ok(u8c), len))
+ },
+ Err(TooShort(1)) => None,
+ Err(e) => {
+ self.index += 1;
+ Some((start, Err(e), 1))
+ }
+ }
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize,Option<usize>) {
+ let bytes = self.slice.len() - self.index;
+ // Cannot be exact, so KISS and don't bother rounding up.
+ // The slice is unlikely be full of 4-byte codepoints, so buffers
+ // allocated with the lower bound will have to be grown anyway.
+ (bytes/4, Some(bytes))
+ }
+}
+impl<'a> DoubleEndedIterator for Utf8CharDecoder<'a> {
+ fn next_back(&mut self) -> Option<Self::Item> {
+ if self.index < self.slice.len() {
+ let extras = self.slice.iter()
+ .rev()
+ .take_while(|&b| b & 0b1100_0000 == 0b1000_0000 )
+ .count();
+ let starts = self.slice.len() - (extras+1);
+ match Utf8Char::from_slice_start(&self.slice[starts..]) {
+ Ok((u8c,len)) if len == 1+extras => {
+ self.slice = &self.slice[..starts];
+ Some((starts, Ok(u8c), len))
+ },
+ // This enures errors for every byte in both directions,
+ // but means overlong and codepoint errors will be turned into
+ // tooshort errors.
+ Err(e) if extras == 0 => {
+ self.slice = &self.slice[..self.slice.len()-1];
+ Some((self.slice.len()-1, Err(e), 1))
+ },
+ _ => {
+ self.slice = &self.slice[..self.slice.len()-1];
+ Some((self.slice.len()-1, Err(Utf8(FirstByte(ContinuationByte))), 1))
+ },
+ }
+ } else {
+ None
+ }
+ }
+}
+impl<'a> Debug for Utf8CharDecoder<'a> {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ write!(fmtr, "Utf8CharDecoder {{ bytes[{}..]: {:?} }}", self.index, self.as_slice())
+ }
+}
+
+
+
+/// Decodes UTF-16 characters from a `u16` iterator into `Utf16Char`s.
+///
+/// See [`IterExt::to_utf16chars()`](../trait.IterExt.html#tymethod.to_utf16chars)
+/// for examples and error handling.
+#[derive(Clone, Default)]
+pub struct Utf16CharMerger<B:Borrow<u16>, I:Iterator<Item=B>> {
+ iter: I,
+ /// Used when a trailing surrogate was expected, the u16 can be any value.
+ prev: Option<B>,
+}
+impl<B:Borrow<u16>, I:Iterator<Item=B>, T:IntoIterator<IntoIter=I,Item=B>>
+From<T> for Utf16CharMerger<B,I> {
+ fn from(t: T) -> Self {
+ Utf16CharMerger { iter: t.into_iter(), prev: None }
+ }
+}
+impl<B:Borrow<u16>, I:Iterator<Item=B>> Utf16CharMerger<B,I> {
+ /// Extract the inner iterator.
+ ///
+ /// If the last item produced was an `Err`, the first unit might be missing.
+ ///
+ /// # Examples
+ ///
+ /// Unit right after an error missing
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// # use encode_unicode::error::Utf16PairError;
+ /// let mut merger = [0xd901, 'F' as u16, 'S' as u16].iter().to_utf16chars();
+ /// assert_eq!(merger.next(), Some(Err(Utf16PairError::UnmatchedLeadingSurrogate)));
+ /// let mut inner: std::slice::Iter<u16> = merger.into_inner();
+ /// assert_eq!(inner.next(), Some('S' as u16).as_ref()); // 'F' was consumed by Utf16CharMerger
+ /// ```
+ ///
+ /// Error that doesn't swallow any units
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// # use encode_unicode::error::Utf16PairError;
+ /// let mut merger = [0xde00, 'F' as u16, 'S' as u16].iter().to_utf16chars();
+ /// assert_eq!(merger.next(), Some(Err(Utf16PairError::UnexpectedTrailingSurrogate)));
+ /// let mut inner: std::slice::Iter<u16> = merger.into_inner();
+ /// assert_eq!(inner.next(), Some('F' as u16).as_ref()); // not consumed
+ /// ```
+ pub fn into_inner(self) -> I {
+ self.iter
+ }
+ /// Returns an iterator over the remaining units.
+ /// Unlike `into_inner()` this will never drop any units.
+ ///
+ /// The exact type of the returned iterator should not be depended on.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use encode_unicode::IterExt;
+ /// # use encode_unicode::error::Utf16PairError;
+ /// let slice = [0xd901, 'F' as u16, 'S' as u16];
+ /// let mut merger = slice.iter().to_utf16chars();
+ /// assert_eq!(merger.next(), Some(Err(Utf16PairError::UnmatchedLeadingSurrogate)));
+ /// let mut remaining = merger.into_remaining_units();
+ /// assert_eq!(remaining.next(), Some('F' as u16).as_ref());
+ /// ```
+ pub fn into_remaining_units(self) -> Chain<option::IntoIter<B>,I> {
+ self.prev.into_iter().chain(self.iter)
+ }
+}
+impl<B:Borrow<u16>, I:Iterator<Item=B>> Iterator for Utf16CharMerger<B,I> {
+ type Item = Result<Utf16Char,Utf16PairError>;
+ fn next(&mut self) -> Option<Self::Item> {
+ let first = self.prev.take().or_else(|| self.iter.next() );
+ first.map(|first| unsafe {
+ match first.borrow().utf16_needs_extra_unit() {
+ Ok(false) => Ok(Utf16Char::from_array_unchecked([*first.borrow(), 0])),
+ Ok(true) => match self.iter.next() {
+ Some(second) => match second.borrow().utf16_needs_extra_unit() {
+ Err(InvalidUtf16FirstUnit) => Ok(Utf16Char::from_tuple_unchecked((
+ *first.borrow(),
+ Some(*second.borrow())
+ ))),
+ Ok(_) => {
+ self.prev = Some(second);
+ Err(Utf16PairError::UnmatchedLeadingSurrogate)
+ }
+ },
+ None => Err(Utf16PairError::Incomplete)
+ },
+ Err(InvalidUtf16FirstUnit) => Err(Utf16PairError::UnexpectedTrailingSurrogate),
+ }
+ })
+ }
+ fn size_hint(&self) -> (usize,Option<usize>) {
+ let (iter_min, iter_max) = self.iter.size_hint();
+ // cannot be exact, so KISS
+ let min = iter_min / 2; // don't bother rounding up or accounting for self.prev
+ let max = match (iter_max, &self.prev) {
+ (Some(max), &Some(_)) => max.checked_add(1),
+ (max, _) => max,
+ };
+ (min, max)
+ }
+}
+impl<B:Borrow<u16>, I:Iterator<Item=B>+Debug> Debug for Utf16CharMerger<B,I> {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ fmtr.debug_struct("Utf16CharMerger")
+ .field("buffered", &self.prev.as_ref().map(|b| *b.borrow() ))
+ .field("inner", &self.iter)
+ .finish()
+ }
+}
+
+
+/// An [`Utf16CharMerger`](struct.Utf16CharMerger.html) that also produces
+/// offsets and lengths, but can only iterate over slices.
+///
+/// See [`SliceExt::utf16char_indices()`](../trait.SliceExt.html#tymethod.utf16char_indices)
+/// for examples and error handling.
+#[derive(Clone, Default)]
+pub struct Utf16CharDecoder<'a> {
+ slice: &'a[u16],
+ index: usize,
+}
+impl<'a> From<&'a[u16]> for Utf16CharDecoder<'a> {
+ fn from(s: &'a[u16]) -> Self {
+ Utf16CharDecoder{ slice: s, index: 0 }
+ }
+}
+impl<'a> Utf16CharDecoder<'a> {
+ /// Extract the remainder of the source slice.
+ ///
+ /// # Examples
+ ///
+ /// Unlike `Utf16CharMerger::into_inner()`, the unit after an error is never swallowed:
+ /// ```
+ /// # use encode_unicode::SliceExt;
+ /// # use encode_unicode::error::Utf16PairError;
+ /// let mut iter = [0xd901, 'F' as u16, 'S' as u16].utf16char_indices();
+ /// assert_eq!(iter.next(), Some((0, Err(Utf16PairError::UnmatchedLeadingSurrogate), 1)));
+ /// assert_eq!(iter.as_slice(), &['F' as u16, 'S' as u16]);
+ /// ```
+ pub fn as_slice(&self) -> &[u16] {
+ &self.slice[self.index..]
+ }
+}
+impl<'a> Iterator for Utf16CharDecoder<'a> {
+ type Item = (usize,Result<Utf16Char,Utf16PairError>,usize);
+ #[inline]
+ fn next(&mut self) -> Option<Self::Item> {
+ let start = self.index;
+ match Utf16Char::from_slice_start(self.as_slice()) {
+ Ok((u16c,len)) => {
+ self.index += len;
+ Some((start, Ok(u16c), len))
+ },
+ Err(EmptySlice) => None,
+ Err(FirstLowSurrogate) => {
+ self.index += 1;
+ Some((start, Err(UnexpectedTrailingSurrogate), 1))
+ },
+ Err(SecondNotLowSurrogate) => {
+ self.index += 1;
+ Some((start, Err(UnmatchedLeadingSurrogate), 1))
+ },
+ Err(MissingSecond) => {
+ self.index = self.slice.len();
+ Some((start, Err(Incomplete), 1))
+ }
+ }
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize,Option<usize>) {
+ let units = self.slice.len() - self.index;
+ // Cannot be exact, so KISS and don't bother rounding up.
+ // The slice is unlikely be full of surrogate pairs, so buffers
+ // allocated with the lower bound will have to be grown anyway.
+ (units/2, Some(units))
+ }
+}
+impl<'a> Debug for Utf16CharDecoder<'a> {
+ fn fmt(&self, fmtr: &mut fmt::Formatter) -> fmt::Result {
+ write!(fmtr, "Utf16CharDecoder {{ units[{}..]: {:?} }}", self.index, self.as_slice())
+ }
+}
--
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