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+// Copyright 2014-2017 The html5ever 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.
+
+//! This module contains a single struct [`SmallCharSet`]. See its documentation for details.
+//!
+//! [`SmallCharSet`]: struct.SmallCharSet.html
+
+/// Represents a set of "small characters", those with Unicode scalar
+/// values less than 64.
+///
+/// This is stored as a bitmap, with 1 bit for each value.
+#[derive(Debug, Eq, PartialEq, Clone, Copy, Hash)]
+pub struct SmallCharSet {
+ pub bits: u64,
+}
+
+impl SmallCharSet {
+ /// Checks whether a character (u8 value below 64) is stored in the SmallCharSet.
+ ///
+ /// # Examples
+ ///
+ /// ```ignore
+ /// # use markup5ever::SmallCharSet;
+ /// let set = SmallCharSet {
+ /// bits: 0b00000000_01000000_00000100_00000000_00000000_00000000_00010000_00000000
+ /// };
+ /// assert!(set.contains(64));
+ /// assert!(set.contains(b'6')); // `b'6'` is the same as 64u8
+ /// ```
+ #[inline]
+ fn contains(&self, n: u8) -> bool {
+ 0 != (self.bits & (1 << (n as usize)))
+ }
+
+ /// Count the number of bytes of characters at the beginning of `buf` which are not in the set.
+ ///
+ /// This functionality is used in [`BufferQueue::pop_except_from`].
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # #[macro_use] extern crate markup5ever;
+ /// # fn main() {
+ /// let set = small_char_set!(48 49 50); // '0' '1' '2'
+ /// // `test` is 4 chars, ๐Ÿ˜ is 4 chars, then we meet a character in the set
+ /// let test_str = "test๐Ÿ˜01232afd";
+ /// assert_eq!(set.nonmember_prefix_len(test_str), 8);
+ /// # }
+ /// ```
+ ///
+ /// [`BufferQueue::pop_except_from`]: buffer_queue/struct.BufferQueue.html#method.pop_except_from
+ pub fn nonmember_prefix_len(&self, buf: &str) -> u32 {
+ let mut n = 0;
+ for b in buf.bytes() {
+ if b >= 64 || !self.contains(b) {
+ n += 1;
+ } else {
+ break;
+ }
+ }
+ n
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use std::iter::repeat;
+
+ #[test]
+ fn nonmember_prefix() {
+ for &c in ['&', '\0'].iter() {
+ for x in 0..48u32 {
+ for y in 0..48u32 {
+ let mut s = repeat("x").take(x as usize).collect::<String>();
+ s.push(c);
+ s.push_str(&repeat("x").take(y as usize).collect::<String>());
+ let set = small_char_set!('&' '\0');
+
+ assert_eq!(x, set.nonmember_prefix_len(&s));
+ }
+ }
+ }
+ }
+}