croaring_mw/bitmap/
iter.rs

1use std::iter::{FromIterator, IntoIterator};
2use std::marker::PhantomData;
3
4use super::{ffi, Bitmap};
5
6pub struct BitmapIterator<'a> {
7    iterator: *mut ffi::roaring_uint32_iterator_s,
8    phantom: PhantomData<&'a ()>,
9}
10
11impl<'a> BitmapIterator<'a> {
12    fn new(bitmap: &Bitmap) -> Self {
13        BitmapIterator {
14            iterator: unsafe { ffi::roaring_create_iterator(bitmap.bitmap) },
15            phantom: PhantomData,
16        }
17    }
18
19    #[inline]
20    fn current_value(&self) -> Option<u32> {
21        unsafe {
22            if self.has_value() {
23                Some((*self.iterator).current_value)
24            } else {
25                None
26            }
27        }
28    }
29
30    #[inline]
31    fn has_value(&self) -> bool {
32        unsafe { (*self.iterator).has_value }
33    }
34
35    #[inline]
36    fn advance(&mut self) -> bool {
37        unsafe { ffi::roaring_advance_uint32_iterator(self.iterator) }
38    }
39}
40
41impl<'a> Iterator for BitmapIterator<'a> {
42    type Item = u32;
43
44    fn next(&mut self) -> Option<Self::Item> {
45        match self.current_value() {
46            Some(value) => {
47                self.advance();
48
49                Some(value)
50            }
51            None => None,
52        }
53    }
54}
55
56impl<'a> Drop for BitmapIterator<'a> {
57    fn drop(&mut self) {
58        unsafe { ffi::roaring_free_uint32_iterator(self.iterator) }
59    }
60}
61
62impl Bitmap {
63    /// Returns an iterator over each value stored in the bitmap.
64    /// Returned values are ordered in ascending order.
65    ///
66    /// # Examples
67    ///
68    /// ```
69    /// use croaring::Bitmap;
70    ///
71    /// let mut bitmap = Bitmap::create();
72    /// bitmap.add(4);
73    /// bitmap.add(3);
74    /// bitmap.add(2);
75    /// let mut iterator = bitmap.iter();
76    ///
77    /// assert_eq!(iterator.next(), Some(2));
78    /// assert_eq!(iterator.next(), Some(3));
79    /// assert_eq!(iterator.next(), Some(4));
80    /// assert_eq!(iterator.next(), None);
81    /// ```
82    pub fn iter(&self) -> BitmapIterator {
83        BitmapIterator::new(self)
84    }
85}
86
87impl FromIterator<u32> for Bitmap {
88    /// Convenience method for creating bitmap from iterator.
89    ///
90    /// # Examples
91    ///
92    /// ```
93    /// use croaring::Bitmap;
94    ///
95    /// let bitmap: Bitmap = (1..3).collect();
96    ///
97    /// assert!(!bitmap.is_empty());
98    /// assert!(bitmap.contains(1));
99    /// assert!(bitmap.contains(2));
100    /// assert_eq!(bitmap.cardinality(), 2);
101    /// ```
102    fn from_iter<I: IntoIterator<Item = u32>>(iter: I) -> Self {
103        Bitmap::of(&Vec::from_iter(iter))
104    }
105}
croaring_mw/bitmap/iter.rs

croaring_mw/bitmap/
iter.rs
