1 files changed, 151 insertions, 0 deletions
diff --git a/vendor/unic-char-range/src/iter.rs b/vendor/unic-char-range/src/iter.rs
new file mode 100644
index 000000000..44901dfe3
--- /dev/null
+++ b/vendor/unic-char-range/src/iter.rs
@@ -0,0 +1,151 @@
+// Copyright 2017 The UNIC Project Developers.
+//
+// See the COPYRIGHT file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.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 core::{char, ops};
+
+use crate::{step, CharRange};
+
+const SURROGATE_RANGE: ops::Range<u32> = 0xD800..0xE000;
+
+/// An iterator over a range of unicode code points.
+///
+/// Constructed via `CharRange::iter`. See `CharRange` for more information.
+#[derive(Clone, Debug)]
+pub struct CharIter {
+    /// The lowest uniterated character (inclusive).
+    ///
+    /// Iteration is finished if this is higher than `high`.
+    low: char,
+
+    /// The highest uniterated character (inclusive).
+    ///
+    /// Iteration is finished if this is lower than `low`.
+    high: char,
+}
+
+impl From<CharRange> for CharIter {
+    fn from(range: CharRange) -> CharIter {
+        CharIter {
+            low: range.low,
+            high: range.high,
+        }
+    }
+}
+
+impl From<CharIter> for CharRange {
+    fn from(iter: CharIter) -> CharRange {
+        CharRange {
+            low: iter.low,
+            high: iter.high,
+        }
+    }
+}
+
+impl CharIter {
+    #[inline]
+    #[allow(unsafe_code)]
+    // When stepping `self.low` forward would go over `char::MAX`,
+    // Set `self.high` to `'\0'` instead. It will have the same effect --
+    // consuming the last element from the iterator and ending iteration.
+    fn step_forward(&mut self) {
+        if self.low == char::MAX {
+            self.high = '\0'
+        } else {
+            self.low = unsafe { step::forward(self.low) }
+        }
+    }
+
+    #[inline]
+    #[allow(unsafe_code)]
+    // When stepping `self.high` backward would cause underflow,
+    // set `self.low` to `char::MAX` instead. It will have the same effect --
+    // consuming the last element from the iterator and ending iteration.
+    fn step_backward(&mut self) {
+        if self.high == '\0' {
+            self.low = char::MAX;
+        } else {
+            self.high = unsafe { step::backward(self.high) }
+        }
+    }
+
+    #[inline]
+    /// ExactSizeIterator::is_empty() for stable
+    fn is_finished(&self) -> bool {
+        self.low > self.high
+    }
+}
+
+impl Iterator for CharIter {
+    type Item = char;
+
+    #[inline]
+    fn next(&mut self) -> Option<char> {
+        if self.is_finished() {
+            return None;
+        }
+
+        let ch = self.low;
+        self.step_forward();
+        Some(ch)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.len();
+        (len, Some(len))
+    }
+
+    fn last(self) -> Option<char> {
+        if self.is_finished() {
+            None
+        } else {
+            Some(self.high)
+        }
+    }
+
+    fn max(self) -> Option<char> {
+        self.last()
+    }
+
+    fn min(mut self) -> Option<char> {
+        self.next()
+    }
+}
+
+impl DoubleEndedIterator for CharIter {
+    #[inline]
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if self.is_finished() {
+            None
+        } else {
+            let ch = self.high;
+            self.step_backward();
+            Some(ch)
+        }
+    }
+}
+
+impl ExactSizeIterator for CharIter {
+    fn len(&self) -> usize {
+        if self.is_finished() {
+            return 0;
+        }
+        let naive_range = (self.low as u32)..(self.high as u32 + 1);
+        if naive_range.start <= SURROGATE_RANGE.start && SURROGATE_RANGE.end <= naive_range.end {
+            naive_range.len() - SURROGATE_RANGE.len()
+        } else {
+            naive_range.len()
+        }
+    }
+
+    #[cfg(feature = "exact-size-is-empty")]
+    fn is_empty(&self) -> bool {
+        self.is_finished()
+    }
+}