1 files changed, 352 insertions, 0 deletions
diff --git a/vendor/encode_unicode/src/utf8_iterators.rs b/vendor/encode_unicode/src/utf8_iterators.rs
new file mode 100644
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+++ b/vendor/encode_unicode/src/utf8_iterators.rs
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+/* 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 utf8_char::Utf8Char;
+use errors::EmptyStrError;
+extern crate core;
+use self::core::{mem, u32, u64};
+use self::core::ops::Not;
+use self::core::fmt;
+use self::core::borrow::Borrow;
+#[cfg(feature="std")]
+use std::io::{Read, Error as ioError};
+
+
+
+/// Read or iterate over the bytes of the UTF-8 representation of a codepoint.
+#[derive(Clone)]
+pub struct Utf8Iterator (u32);
+
+impl From<Utf8Char> for Utf8Iterator {
+    fn from(uc: Utf8Char) -> Self {
+        let used = u32::from_le(unsafe{ mem::transmute(uc.to_array().0) });
+        // uses u64 because shifting an u32 by 32 bits is a no-op.
+        let unused_set = (u64::MAX  <<  uc.len() as u64*8) as u32;
+        Utf8Iterator(used | unused_set)
+    }
+}
+impl From<char> for Utf8Iterator {
+    fn from(c: char) -> Self {
+        Self::from(Utf8Char::from(c))
+    }
+}
+impl Iterator for Utf8Iterator {
+    type Item=u8;
+    fn next(&mut self) -> Option<u8> {
+        let next = self.0 as u8;
+        if next == 0xff {
+            None
+        } else {
+            self.0 = (self.0 >> 8)  |  0xff_00_00_00;
+            Some(next)
+        }
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.len(),  Some(self.len()))
+    }
+}
+impl ExactSizeIterator for Utf8Iterator {
+    fn len(&self) -> usize {// not straightforward, but possible
+        let unused_bytes = self.0.not().leading_zeros() / 8;
+        4 - unused_bytes as usize
+    }
+}
+#[cfg(feature="std")]
+impl Read for Utf8Iterator {
+    /// Always returns Ok
+    fn read(&mut self,  buf: &mut[u8]) -> Result<usize, ioError> {
+        // Cannot call self.next() until I know I can write the result.
+        for (i, dst) in buf.iter_mut().enumerate() {
+            match self.next() {
+                Some(b) => *dst = b,
+                None    => return Ok(i),
+            }
+        }
+        Ok(buf.len())
+    }
+}
+impl fmt::Debug for Utf8Iterator {
+    fn fmt(&self,  fmtr: &mut fmt::Formatter) -> fmt::Result {
+        let mut content = [0; 4];
+        let mut i = 0;
+        for b in self.clone() {
+            content[i] = b;
+            i += 1;
+        }
+        write!(fmtr, "{:?}", &content[..i])
+    }
+}
+
+
+
+/// Converts an iterator of `Utf8Char` (or `&Utf8Char`)
+/// to an iterator of `u8`s.  
+/// Is equivalent to calling `.flat_map()` on the original iterator,
+/// but the returned iterator is ~40% faster.
+///
+/// The iterator also implements `Read` (if the `std` feature isn't disabled).
+/// Reading will never produce an error, and calls to `.read()` and `.next()`
+/// can be mixed.
+///
+/// The exact number of bytes cannot be known in advance, but `size_hint()`
+/// gives the possible range.
+/// (min: all remaining characters are ASCII, max: all require four bytes)
+///
+/// # Examples
+///
+/// From iterator of values:
+///
+/// ```
+/// use encode_unicode::{iter_bytes, CharExt};
+///
+/// let iterator = "foo".chars().map(|c| c.to_utf8() );
+/// let mut bytes = [0; 4];
+/// for (u,dst) in iter_bytes(iterator).zip(&mut bytes) {*dst=u;}
+/// assert_eq!(&bytes, b"foo\0");
+/// ```
+///
+/// From iterator of references:
+///
+#[cfg_attr(feature="std", doc=" ```")]
+#[cfg_attr(not(feature="std"), doc=" ```no_compile")]
+/// use encode_unicode::{iter_bytes, CharExt, Utf8Char};
+///
+/// let chars: Vec<Utf8Char> = "💣 bomb 💣".chars().map(|c| c.to_utf8() ).collect();
+/// let bytes: Vec<u8> = iter_bytes(&chars).collect();
+/// let flat_map: Vec<u8> = chars.iter().flat_map(|u8c| *u8c ).collect();
+/// assert_eq!(bytes, flat_map);
+/// ```
+///
+/// `Read`ing from it:
+///
+#[cfg_attr(feature="std", doc=" ```")]
+#[cfg_attr(not(feature="std"), doc=" ```no_compile")]
+/// use encode_unicode::{iter_bytes, CharExt};
+/// use std::io::Read;
+///
+/// let s = "Ååh‽";
+/// assert_eq!(s.len(), 8);
+/// let mut buf = [b'E'; 9];
+/// let mut reader = iter_bytes(s.chars().map(|c| c.to_utf8() ));
+/// assert_eq!(reader.read(&mut buf[..]).unwrap(), 8);
+/// assert_eq!(reader.read(&mut buf[..]).unwrap(), 0);
+/// assert_eq!(&buf[..8], s.as_bytes());
+/// assert_eq!(buf[8], b'E');
+/// ```
+pub fn iter_bytes<U:Borrow<Utf8Char>, I:IntoIterator<Item=U>>
+(iterable: I) -> Utf8CharSplitter<U, I::IntoIter> {
+    Utf8CharSplitter{ inner: iterable.into_iter(),  prev: 0 }
+}
+
+/// The iterator type returned by `iter_bytes()`
+///
+/// See its documentation for details.
+#[derive(Clone)]
+pub struct Utf8CharSplitter<U:Borrow<Utf8Char>, I:Iterator<Item=U>> {
+    inner: I,
+    prev: u32,
+}
+impl<I:Iterator<Item=Utf8Char>> From<I> for Utf8CharSplitter<Utf8Char,I> {
+    /// A less generic constructor than `iter_bytes()`
+    fn from(iter: I) -> Self {
+        iter_bytes(iter)
+    }
+}
+impl<U:Borrow<Utf8Char>, I:Iterator<Item=U>> Utf8CharSplitter<U,I> {
+    /// Extracts the source iterator.
+    ///
+    /// Note that `iter_bytes(iter.into_inner())` is not a no-op:  
+    /// If the last returned byte from `next()` was not an ASCII by,
+    /// the remaining bytes of that codepoint is lost.
+    pub fn into_inner(self) -> I {
+        self.inner
+    }
+}
+impl<U:Borrow<Utf8Char>, I:Iterator<Item=U>> Iterator for Utf8CharSplitter<U,I> {
+    type Item = u8;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.prev == 0 {
+            self.inner.next().map(|u8c| {
+                let array = u8c.borrow().to_array().0;
+                self.prev = unsafe{ u32::from_le(mem::transmute(array)) } >> 8;
+                array[0]
+            })
+        } else {
+            let next = self.prev as u8;
+            self.prev >>= 8;
+            Some(next)
+        }
+    }
+    fn size_hint(&self) -> (usize,Option<usize>) {
+        // Doesn't need to handle unlikely overflows correctly because
+        // size_hint() cannot be relied upon anyway. (the trait isn't unsafe)
+        let (min, max) = self.inner.size_hint();
+        let add = 4 - (self.prev.leading_zeros() / 8) as usize;
+        (min.wrapping_add(add), max.map(|max| max.wrapping_mul(4).wrapping_add(add) ))
+    }
+}
+#[cfg(feature="std")]
+impl<U:Borrow<Utf8Char>, I:Iterator<Item=U>> Read for Utf8CharSplitter<U,I> {
+    /// Always returns `Ok`
+    fn read(&mut self,  buf: &mut[u8]) -> Result<usize, ioError> {
+        let mut i = 0;
+        // write remaining bytes of previous codepoint
+        while self.prev != 0  &&  i < buf.len() {
+            buf[i] = self.prev as u8;
+            self.prev >>= 8;
+            i += 1;
+        }
+        // write whole characters
+        while i < buf.len() {
+            let bytes = match self.inner.next() {
+                Some(u8c) => u8c.borrow().to_array().0,
+                None => break
+            };
+            buf[i] = bytes[0];
+            i += 1;
+            if bytes[1] != 0 {
+                let len = bytes[0].not().leading_zeros() as usize;
+                let mut written = 1;
+                while written < len {
+                    if i < buf.len() {
+                        buf[i] = bytes[written];
+                        i += 1;
+                        written += 1;
+                    } else {
+                        let bytes_as_u32 = unsafe{ u32::from_le(mem::transmute(bytes)) };
+                        self.prev = bytes_as_u32 >> (8*written);
+                        return Ok(i);
+                    }
+                }
+            }
+        }
+        Ok(i)
+    }
+}
+
+
+
+/// An iterator over the `Utf8Char` of a string slice, and their positions.
+///
+/// This struct is created by the `utf8char_indices() method from [`StrExt`] trait. See its documentation for more.
+#[derive(Clone)]
+pub struct Utf8CharIndices<'a>{
+    str: &'a str,
+    index: usize,
+}
+impl<'a> From<&'a str> for Utf8CharIndices<'a> {
+    fn from(s: &str) -> Utf8CharIndices {
+        Utf8CharIndices{str: s, index: 0}
+    }
+}
+impl<'a> Utf8CharIndices<'a> {
+    /// Extract the remainder of the source `str`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use encode_unicode::{StrExt, Utf8Char};
+    /// let mut iter = "abc".utf8char_indices();
+    /// assert_eq!(iter.next_back(), Some((2, Utf8Char::from('c'))));
+    /// assert_eq!(iter.next(), Some((0, Utf8Char::from('a'))));
+    /// assert_eq!(iter.as_str(), "b");
+    /// ```
+    pub fn as_str(&self) -> &'a str {
+        &self.str[self.index..]
+    }
+}
+impl<'a> Iterator for Utf8CharIndices<'a> {
+    type Item = (usize,Utf8Char);
+    fn next(&mut self) -> Option<(usize,Utf8Char)> {
+        match Utf8Char::from_str_start(&self.str[self.index..]) {
+            Ok((u8c, len)) => {
+                let item = (self.index, u8c);
+                self.index += len;
+                Some(item)
+            },
+            Err(EmptyStrError) => None
+        }
+    }
+    fn size_hint(&self) -> (usize,Option<usize>) {
+        let len = self.str.len() - self.index;
+        // For len+3 to overflow, the slice must fill all but two bytes of
+        // addressable memory, and size_hint() doesn't need to be correct.
+        (len.wrapping_add(3)/4, Some(len))
+    }
+}
+impl<'a> DoubleEndedIterator for Utf8CharIndices<'a> {
+    fn next_back(&mut self) -> Option<(usize,Utf8Char)> {
+        // Cannot refactor out the unwrap without switching to ::from_slice()
+        // since slicing the str panics if not on a boundary.
+        if self.index < self.str.len() {
+            let rev = self.str.bytes().rev();
+            let len = 1 + rev.take_while(|b| b & 0b1100_0000 == 0b1000_0000 ).count();
+            let starts = self.str.len() - len;
+            let (u8c,_) = Utf8Char::from_str_start(&self.str[starts..]).unwrap();
+            self.str = &self.str[..starts];
+            Some((starts, u8c))
+        } else {
+            None
+        }
+    }
+}
+impl<'a> fmt::Debug for Utf8CharIndices<'a> {
+    fn fmt(&self,  fmtr: &mut fmt::Formatter) -> fmt::Result {
+        fmtr.debug_tuple("Utf8CharIndices")
+            .field(&self.index)
+            .field(&self.as_str())
+            .finish()
+    }
+}
+
+
+/// An iterator over the codepoints in a `str` represented as `Utf8Char`.
+#[derive(Clone)]
+pub struct Utf8Chars<'a>(Utf8CharIndices<'a>);
+impl<'a> From<&'a str> for Utf8Chars<'a> {
+    fn from(s: &str) -> Utf8Chars {
+        Utf8Chars(Utf8CharIndices::from(s))
+    }
+}
+impl<'a> Utf8Chars<'a> {
+    /// Extract the remainder of the source `str`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use encode_unicode::{StrExt, Utf8Char};
+    /// let mut iter = "abc".utf8chars();
+    /// assert_eq!(iter.next(), Some(Utf8Char::from('a')));
+    /// assert_eq!(iter.next_back(), Some(Utf8Char::from('c')));
+    /// assert_eq!(iter.as_str(), "b");
+    /// ```
+    pub fn as_str(&self) -> &'a str {
+        self.0.as_str()
+    }
+}
+impl<'a> Iterator for Utf8Chars<'a> {
+    type Item = Utf8Char;
+    fn next(&mut self) -> Option<Utf8Char> {
+        self.0.next().map(|(_,u8c)| u8c )
+    }
+    fn size_hint(&self) -> (usize,Option<usize>) {
+        self.0.size_hint()
+    }
+}
+impl<'a> DoubleEndedIterator for Utf8Chars<'a> {
+    fn next_back(&mut self) -> Option<Utf8Char> {
+        self.0.next_back().map(|(_,u8c)| u8c )
+    }
+}
+impl<'a> fmt::Debug for Utf8Chars<'a> {
+    fn fmt(&self,  fmtr: &mut fmt::Formatter) -> fmt::Result {
+        fmtr.debug_tuple("Utf8CharIndices")
+            .field(&self.as_str())
+            .finish()
+    }
+}