enumoid 0.1.1

Enum Indexed Containers
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

use crate::base::EnumFlagsHelper;
use std::fmt;
use std::fmt::Debug;
use std::ops::{Index, Range};

/// A set of enumoid `T`'s members.
#[derive(Copy, Clone)]
pub struct EnumFlags<T: EnumFlagsHelper> {
  data: T::FlagsArray,
}

const BITS: usize = 8;

impl<T: EnumFlagsHelper> EnumFlags<T> {
  pub fn new() -> Self {
    EnumFlags {
      data: Default::default(),
    }
  }

  #[inline]
  pub(crate) fn set_internal(&mut self, i: usize, x: bool) {
    debug_assert!(i < T::SIZE, "Enum out of bounds: {} >= {}", i, T::SIZE);
    let j = i / BITS;
    let mask = 1 << (i % BITS);
    let slice = T::slice_flags_mut(&mut self.data);
    slice[j] = if x { slice[j] | mask } else { slice[j] & !mask }
  }

  pub fn set(&mut self, e: T, x: bool) {
    self.set_internal(T::into_usize(e), x)
  }

  pub fn clear(&mut self) {
    self.data = Default::default();
  }

  #[inline]
  pub(crate) fn get_internal(&self, i: usize) -> bool {
    debug_assert!(i < T::SIZE, "Enum out of bounds: {} >= {}", i, T::SIZE);
    let j = i / BITS;
    let slice = T::slice_flags(&self.data);
    (slice[j] >> (i % BITS)) & 1 == 1
  }

  pub fn get(&self, e: T) -> bool {
    self.get_internal(T::into_usize(e))
  }

  pub fn iter(&self) -> EnumFlagsIter<T> {
    EnumFlagsIter {
      flags: self,
      iter: 0..T::SIZE,
    }
  }

  pub fn count(&self) -> usize {
    let slice = T::slice_flags(&self.data);
    slice
      .iter()
      .fold(0, |acc, &val| acc + val.count_ones() as usize)
  }

  pub fn any(&self) -> bool {
    let slice = T::slice_flags(&self.data);
    slice.iter().any(|&val| val != 0)
  }

  pub fn all(&self) -> bool {
    let slice = T::slice_flags(&self.data);
    let last = !0 >> (BITS - T::SIZE % BITS);
    slice[..T::SIZE / BITS].iter().all(|&val| val == !0)
      && (T::SIZE % BITS == 0 || slice[T::SIZE / BITS] == last)
  }
}

impl<T: EnumFlagsHelper + Debug> Debug for EnumFlags<T> {
  fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
    fmt.debug_map().entries(self.iter()).finish()
  }
}

impl<T: EnumFlagsHelper> Default for EnumFlags<T> {
  fn default() -> Self {
    EnumFlags::<T>::new()
  }
}

const TRUE: &bool = &true;
const FALSE: &bool = &false;

impl<T: EnumFlagsHelper> Index<T> for EnumFlags<T> {
  type Output = bool;

  #[inline]
  fn index(&self, i: T) -> &bool {
    if self.get(i) {
      TRUE
    } else {
      FALSE
    }
  }
}

pub struct EnumFlagsIter<'a, T: EnumFlagsHelper> {
  flags: &'a EnumFlags<T>,
  iter: Range<usize>,
}

impl<'a, T: EnumFlagsHelper> Iterator for EnumFlagsIter<'a, T> {
  type Item = (T, bool);

  fn next(&mut self) -> Option<Self::Item> {
    let flags = &self.flags;
    self
      .iter
      .next()
      .map(|i| (T::from_usize(i), flags.get_internal(i)))
  }

  fn size_hint(&self) -> (usize, Option<usize>) {
    self.iter.size_hint()
  }

  fn fold<B, F>(self, init: B, f: F) -> B
  where
    F: FnMut(B, Self::Item) -> B,
  {
    let flags = &self.flags;
    self
      .iter
      .map(|i| (T::from_usize(i), flags.get_internal(i)))
      .fold(init, f)
  }
}